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试验项目
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章节号
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标准要求
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Gas emission
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6.1
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6.1.1 The test shall be carried out with six cells or three monobloc batteries.
6.1.2 The test units shall be selected and prepared according to 5.2.
6.1.3 The test units shall be tested connected in series and maintained during the test between 20℃ and 25 ℃(temperature of test unit). The units shall be fitted with an individual or common gas collection device so that the emitted gas can be collected from all cells over several days and its volume determined with the required accuracy.
6.1.4 The gas collection shall be carried out, for example, with a volumetric measurement or gas collection device similar to that shown in Figure 1. Careful attention shall be paid to ensure leak-free gas transport from the test units to the collection device during long unattended operation. The maximum hydrostatic head (as given by the difference in collection vessel immersion depth and water level) shall be not more than 20 mm.
6.1.5 The test units shall have, before starting the test, an actual capacity Ca of at least Crt (3 h rate - Ufinal 1.70 Vpc at the selected reference temperature), be fully charged and then float charged, in a series string, for 72h ± 0.1 h with the manufacturer’s specified float voltage of n×Uflo ±0,01 Vpc. This voltage shall be recorded and reported. All units shall be checked for absence of leaks before commencing the test.
6.1.6 After 72 h ± 0.1h of float charge, the gas collection shall commence and the collection of gas be continued for four periods each of 168 h±0.1 h duration.
6.1.7 The cumulative total gas volume (Va in mL) collected over each of the four periods of 168 h ± 0.1 h shall be recorded together with the ambient temperature Ta (in K) and the ambient pressure Pa (in kPa) at which each determination of the gas volumes was made.
6.1.8 The corrected volume of gas Vn emitted at the reference temperature of 293 K (20℃) or 298 K (25 ℃) and the reference pressure of 101.3 kPa, shall be calculated by the formula (ignoring correction for water vapour pressure)
Vn=[(Va×Tr)/Ta] ×(Pa/Pr) in ml
where
Va is the cumulative total gas collected of all cells in ml;
Tr is the reference temperature in K (at 293 K or 298 K);
Ta is the ambient temperature (in K) = 273 + Ta (in °C);
Pa is the ambient atmospheric pressure in kPa;
Pr is the reference pressure of 101.3 kPa.
6.1.9 The normalized gas emission Ge per cell at float charge voltage conditions shall be calculated for each of the four 168 h ± 0.1 h periods with the formula below:
Ge = Vn / (n×168 ×Crt) in ml per cell, hour and Ah (rated C3)
where
Vn is the total corrected gas volume emitted per test unit in ml
n is the number of cells from which the gas was collected in the collection vessel
168 is the number of hours during which the gas was collected
Crt is the rated C3 capacity in Ah of the test units from which the gas was collected.
The normalized gas emission Ge per cell at float charge voltage conditions during each of the four periods of 168 h ± 0.1 h of the test shall be reported.
6.1.10 The charge voltage of the same test unit string shall then be increased to
n× 2,40 Vpc ± 0.01 Vpc
6.1.11 After 24 h ± 0.1 h of charge at n × 2,40 Vpc ± 0,01 Vpc the gas collection shall commence and the collection of gas be continued for one period of 48 h ± 0.1 h duration or until 1000 ml have been collected. In this case the time tc (in hours) to collect 1000 ml shall also be reported.
6.1.12 The cumulative total gas volume (Va in ml) collected over one period of 48 h ± 0.1 h shall be recorded together with the ambient temperature Ta (in K) and the ambient pressure Pa (in kPa) at which the determination of the gas volumes was made. If the collection has been stopped at time tc after accumulation of 1 000 ml, the volume after 48 h shall be determined by a simple calculation Va = (1000 ml / tc) ×48 in ml.
6.1.13 The corrected volume of gas Vn emitted at the reference temperature of 293 K(20 °C) or 298 K (25 °C) and the reference pressure of 101.3 kPa shall be calculated by the formula (ignoring correction for water vapour pressure)
Vn=[(Va×Tr)/Ta] ×(Pa/Pr) in ml
where
Va is the cumulative total gas collected of all cells in ml;
Tr is the reference temperature in K (at 293 K or 298 K);
Ta is the ambient temperature (in K) = 273 + Ta (in °C);
Pa is the ambient atmospheric pressure in kPa;
Pr is the reference pressure of 101.3 kPa.
6.1.14 The normalized gas emission Ge per cell at elevated charge voltage (2,40 Vpc)conditions shall be calculated for the 48 h ± 0.1 h period using the formula below:
Ge = Vn / (n×48× Crt) in ml per cell, hour and Ah (rated C3)
where
Vn is the corrected gas volume emitted per test unit in ml
n is the number of cells from which the gas was collected in the collection vessel
48 is the number of hours during which the gas was collected
Crt is the rated C3 capacity in Ah of the test units from which the gas was collected.
The normalized gas emission Ge at elevated charge voltage (2,40 Vpc) conditions during the 48 h ± 0.1 h of the test shall be reported.
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High current tolerance
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6.2
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6.2.1 The test shall be carried out with three cells or three monobloc batteries.
6.2.2 The test units shall be selected and prepared according to 5.2.
6.2.3 The test units shall have, before starting the test, an actual capacity Ca of at least Crt (3 h rate – Ufinal 1,70 Vpc at the selected reference temperature), be fully charged and have unit temperature between 20 °C and 25 °C.
6.2.4 The test units shall be discharged for 30 s with a current equal to 3 times the 5 min rate current (to Ufinal 1,80 Vpc at 20 °C or 25 °C) or with a current equal to the maximum allowable discharge current, both as specified by the manufacturer in the relevant technical documentation of the product range.
6.2.5 After the completion of the specified discharge duration, the test units shall stand for 5 min in open circuit and their voltage measured and reported.
6.2.6 The test units shall be examined, after the discharge, internally and externally for effects of high current flow and signs of melting. The conditions of all three units shall be reported and documented photographically.
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Short-circuit current and d.c. internal resistance
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6.3
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6.3.1 The test shall be carried out with three cells or three monobloc batteries.
6.3.2 The test units shall be selected and prepared according to 5.2.
6.3.3 The test units shall have, before starting the test, an actual capacity Ca of at least Crt(3 h rate – Ufinal 1,70 Vpc at the selected reference temperature), be fully charged and have unit temperature between 20 °C and 25 °C.
NOTE This test is designed to yield values of the possible short circuit current (accuracy ±10 %) capable to be delivered from the cell and monobloc battery when the external circuit has a negligible resistance compared to that of the unit itself. The test also yields the values of the internal (d.c.) resistance of the cell or monobloc battery when this value is derived from the voltage vs. current I relationship during a pulsed discharge of a defined magnitude. The values of short circuit current and internal resistance can be used for the sizing of safety devices such as fuses. It shall be noted that the short circuit current of a fully discharged unit is approximately 60 % of that of a fully charged unit.
6.3.4 The voltage of the test units shall be measured at the terminals of each test unit in order to make sure that no external voltage drop interferes with the test result. A suitable circuit is given in Figure 2.
6.3.5 The short circuit current shall be defined by determining two data pairs in the following way:
a) First data pair (Ua, Ia)
After 20 s of discharge at the current Ia = 4×I10, the voltage and current shall be recorded to give the first data pair. The current shall be interrupted after 25 s maximum and, without recharge and after an open circuit stand of 5 min, the second data pair shall be determined.
b) Second data pairs (Ub, Ib)
After 5 s of discharge at the current Ib = 20 × I10, the voltage and current shall be recorded to give the second data pair.
NOTE When testing very large units and when the test current 20 I10 is beyond the capability of the test equipment it is acceptable to extrapolate the values of Isc and Ri from measurements carried out on units of smaller Ah capacity but of the same design.
6.3.6 The characteristics U = f(I) shall be linearly extrapolated from the two data pairs to U = 0. The intercept indicates the short-circuit current Isc.
The internal resistance Ri can be also determined by interpolation from these two data pairs.
The appropriate formulas for this interpolation are:
Short circuit current Isc = [(Ua× Ib) – (Ub× Ia)] / (Ua – Ub) in amperes
Internal resistance Ri = (Ua – Ub) / (Ib – Ia) in ohms
The individual value of Isc and Ri of all cells and monobloc batteries of the product range shall be reported.
NOTE Interpolations with more data pairs or other test currents or test times can give different short circuit current and internal resistance values.
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Protection against internal ignition from external spark sources
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6.4
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6.4.1 The test (see Table 7) shall be carried out with three fully functional valve assemblies of the concerned cells or monobloc batteries of the product range.
This valve assembly may be a single valve system (screw-in type) or a valve system integrated in the cell or monobloc battery cover.
In both cases all design relevant features (flame barriers, seal lines and similar) shall be present in the valve assembly to be tested.
NOTE This test is designed to validate the degree of protection afforded by the valve and associated flame barriers against the ignition of the gases within a cell by an external spark source. In this test, proper precautions must be taken to safeguard personnel and equipment from explosion hazards and burns.
6.4.2 The test shall be carried out under the guidance of the safety procedures described in IEC 61430 (1997).
6.4.3 The test shall be carried out according to IEC 61430 Clause 4.2 using a test fixture as shown in Figure 3 and placed in an explosion test chamber shown in Figure 2 of IEC 61430. The test shall be carried out at an ambient temperature between 15 °C and 30 °C.
6.4.4 The three functional valve assemblies shall be mounted together onto the test fixture as shown below and be documented photographically in the test report.
6.4.5 The test shall be carried out according to the following procedures and subclauses of IEC 61430.
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Object
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Subclauses of IEC 61430
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Test
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Spark test for a venting system only
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Explosion test chamber
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B.2.1 B.2.1.1 to B.2.1.5
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Procedure
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B.2.2 B.2.2.1 – B.2.2.3
B.2.2.4 – B.2.2.5
(not B.2.2.2)
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Equipment
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Test fixture of Figure 1 of IEC 61430
Test chamber of Figure 2 of IEC 61430
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Test object
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3 complete valve – flame barrier assemblies mounted in parallel
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Gas source
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A fully charged 2V flooded lead-acid cell
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Gas quantity flowing
through the valve assembly
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As produced with 0,2 I10 (A) where I10 is the 10 h current to Ufinal 1,80 Vpc of the largest VRLA cell or monobloc battery using the valve under test.
This current flows through the flooded cell above.
The volume of gas flowing through each of the 3 valves under test is equivalent to
0,2 I10× 0,336× 0,640× 0,333 in litre per hour
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6.4.6 The outcome of the test shall be reported and, for the purposes of IEC 60896-21 and IEC 60896-22, the valve assembly is deemed to have passed the test when no explosion or rapid combustion event occurred within the test fixture.
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Protection against ground short propensity
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6.5
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6.5.1 The test shall be carried out with one cell or monobloc battery.
6.5.2 The test unit shall be selected and prepared according to 5.2
6.5.3 The test unit shall have, before starting the test, an actual capacity Ca of at least 0,95 Crt (3 h rate – Ufinal 1,70 Vpc at the selected reference temperature), be fully charged and have unit temperature between 20 °C and 25 °C.
NOTE This test is designed to determine the resistance of the unit against the development of current flow paths through seals and other points of structural discontinuity. The necessary safety precautions against high voltage, possible explosions and fire must be taken.
6.5.4 The case to cover seal line of the unit shall be placed in contact with a metallic surface. This contact can be achieved, for example, by taping a conducting aluminium foil strip onto the seal line. The injection moulding points at the cell or monobloc battery case bottom can be additional site of ground short propensity and shall be investigated if needed.
6.5.5 The unit shall be placed horizontally (see Figure 4) and sequentially on all four possible faces according to the time schedule in 6.5.8 and 6.5.9 and float charged, with Uflo as specified by the manufacturer, at a room temperature between 20 °C and 25 °C.
6.5.6 The units shall be connected, to a circuit which applies a d.c. voltage of at least 500 V ± 5 V between one terminal and the metallic surface (aluminium foil strip) in contact with the seal line. A suggested test circuit is shown in Figure 5 below
6.5.7 The negative terminal of the d.c. voltage source shall be connected to the terminal of the unit(s) and the positive terminal to the aluminium foil strip.
6.5.8 The unit shall be placed horizontally first on face 1 for 30 days or until either electrolyte leakage (with pH paper, d.c. ohmmeters or similar) or significant ground short current flow (few mA of current) is detected.
6.5.9 After 30 days of test, the unit shall be placed horizontally for 7 days on face 2, followed by 7 days on face 3 followed by 7 days on face 4 or until either electrolyte leakage (with pH paper, d.c. ohmmeters or similar) or significant ground short current flow (few mA of current) is detected.
6.5.10 The presence or absence of ground short/leakage phenomena shall be reported.
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Content and durability of required markings
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6.6
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6.6.1 The test shall be carried out on three of the required markings in their definitive size, form, material and execution. Required markings may be printed, painted or moulded on the case or cover or included in a label affixed to the case or cover.
6.6.2 The test shall consist of visual verification of a) the presence and b) the legibility of all the required markings before and after exposure to selected chemicals.
6.6.3 The durability of the marking shall be tested, consistent with 1.7.13 of IEC 60950-1, as follows:
Test with water and aliphatic solvent.
The procedure is as follows:
a) A label or marking shall be rubbed for 15 s with a piece of cloth soaked with water and again for 15 s with a piece of cloth soaked with petroleum spirit, dried in air and then inspected visually.
b) The petroleum spirit used for this test shall be n-hexane (C6H14 – alkane C6) with an initial boiling point of 65 °C, a dry point of approximately 69 °C, a density of 0,7 kg/l and a maximum aromatic hydrocarbon content of 0,1 % per volume.
Test with neutralizing solutions
The procedure is as follows:
A new label or marking shall be rubbed for 15 s with a piece of cloth soaked with a saturated solution of sodium carbonate (Na2CO3) or bicarbonate (NaHCO3) in water, dried in air and then inspected visually.
Test with electrolyte
The procedure is as follows:
A new label or marking shall be rubbed for 15 s with a piece of cloth soaked with a solution of 40 % in weight of H2SO4 in water, washed with water, dried in air and then inspected visually.
6.6.4 Each required label or marking shall be visually inspected, fully described and depicted photographically before and after the application of the test chemical.
IMPORTANT: Solvents shall not be used to clean cells and monobloc batteries as otherwise damage to the plastic components may result. Approved cleaning fluids are only those expressly specified by the manufacturer.
NOTE The content of the required markings is specified in IEC 60896-22.
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Material identification
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6.7
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6.7.1 The inspection shall be carried out with one cell or monobloc battery cover or case having all the specified information applied in its definitive size, form, material and execution.
If the case material differs from the cover material so as to justify another symbol, the inspection shall be carried out on both the case and the cover.
6.7.2 The specified information for material identification shall be selected from the list of abbreviation published in ISO 1043-1.
6.7.3 The cover and case shall be visually inspected for a marking showing an ISO 1043-1 defined abbreviation of the name of the polymer(s) forming the bulk of the case and/or cover.
6.7.4 The stability of the marking shall be tested, if needed, with the test outlined in 6.6.
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Valve operation
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6.8
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6.8.1 The test shall be carried out with the units destined for the test 6.16 (impact of a stress temperature of 55 °C or 60 °C).
6.8.2 The units shall be tested for valve opening before and at the end of the stress temperature impact test at 55 °C or 60 °C as follows:
a) The units shall be fully charged and at a temperature between 18 °C to 27 °C.
b) The units shall be overcharged with a constant voltage between 2,60 Vpc to 2,70 Vpc for at least 1 h.
c) A gas collection cover shall be placed sequentially onto each valve opening in such a way that all gas released from that valve is captured.
d) If the valve openings are hidden by, or integrated in a gas collection cover or manifold, gas flowing from the outlet of this cover or manifold shall be collected.
e) A tubing shall carry the gas from this collection cover to the bubble detection device such as for example an U-shaped glass tubing of about 15 mm diameter and with the bottom of the U filled with water. See also Figure 6.
f) The opening of each valve, at a test temperature of 18 °C to 27 °C shall be verified visually by detecting the released gas bubbling through the liquid at the bottom of the Ushaped glass tubing.
6.8.3 The observed valve opening (adequate opening or otherwise) before and after the test of 6.16 shall be reported.
NOTE For the correct proper operation of a stationary VRLA battery, air must not enter through the valve when a slight vacuum is present in the cell interior. The adequate valve seal performance of the valve can be tested by creating a vacuum of –40 kPa and confirming, once the vacuum line is disconnected, that a given negative pressure remains for 24 h and the leak rate eventually observed does not interfere with proper operation of the cell or monobloc battery.
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Flammability rating of materials
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6.9
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6.9.1 The test shall be carried out with appropriately sized samples of the material used for the manufacture of the cell or monobloc battery case and, if different, also of the cell or monobloc battery cover.
6.9.2 The test shall be carried out by an appropriate test laboratory.
6.9.3 The test method used shall be in accordance with IEC 60707 and IEC 60695-11-10 or equivalent test methods for all of the above.
6.9.4 The test result and the resulting flammability classification of the material shall appear on a dated and signed test certificate.
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Intercell connector performance
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6.10
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6.10.1 The test shall be carried out with the cells and monobloc batteries destined for the test of 6.11 (discharge capacity at the C0,25 or 0,25 h rate with a current I0.25 to Ufinal = 1,60 Vpc) or alternatively with the highest discharge current for a particular unit and intercell connector size as specified/allowed by the manufacturer in the relevant technical
documentation of the product range The temperature of the units at the start of the test shall be between 20 °C and 25 °C.
6.10.2 The shape, size and construction details and the maximum temperature reached of the intercell connectors during this discharge test shall be reported.
NOTE This test gives an indication of the temperature to be expected during a high rate–short duration discharge. In mission critical installations (UPS battery service) the knowledge of the temperature reached under actual discharge conditions is essential to determine if potential hazards exist.
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Discharge capacity
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6.11
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6.11.1 The test shall be carried out with five times six cells or five times six monobloc batteries.
6.11.2 The test units shall be selected and prepared according to 5.2.
6.11.3 The test for the actual capacity Ca, at the moment of dispatch, shall be carried out at each of the following discharge rates each time with six fully charged units. These units shall not have been previously submitted to any discharge.
The capacities shall be determined with the following rates to the following end-of-discharge
voltages:
C10 10h rate with current I10 to Ufinal = 1,80 Vpc (ë= 0,006)
C8 8h rate with current I8 to Ufinal = 1,75 Vpc (ë= 0,006)
C3 3h rate with current I3 to Ufinal = 1,70 Vpc (ë = 0,006)
C 1h rate with current I1 to Ufinal = 1,60 Vpc (ë= 0,01)
C0,25 0,25h rate with current I0,25 to Ufinal = 1,60 Vpc (ë= 0,01)
(whereë is the rated temperature correction factor of the capacity at the relevant rate)
6.11.4 The test shall be carried out with the units fully charged and with each unit temperature between 18 °C and 27 °C measured immediately prior the discharge.
This initial temperature q of the unit shall be used for the correction of its capacity in function of temperature.
NOTE 1 It is desirable that the initial average cell or monobloc battery temperature and the ambient temperature be as near to the reference temperature of either 20 °C or 25 °C as practically possible.
NOTE 2 For several applications the knowledge of the performance of the units under constant power discharge conditions is necessary. These performance data shall be gathered with actual discharges where the power delivered from a unit is held constant and not by means of calculation from average discharge voltage levels.
6.11.5 The discharge shall be started within 1 h to 24 h after termination of charge and with the discharge current Idis held constant within 1 % throughout the whole discharge duration.
6.11.6 The voltage measured at the terminals, including one intercell connector length, of all the units shall be either recorded automatically against time or by taking the readings manually with a voltmeter. In the latter case readings shall be made at least at 25 %, 50 % and 80 % of the calculated discharge time with:
t = Crt / Irt (h)
and then at suitable time intervals, which permits the detection of the transition to the final discharge voltage Ufinal.
6.11.7 In a type test for the determination of the actual capacity Ca at the moment of dispatch with five discharge rates (this subclause), the discharge shall be terminated when the following value has been recorded from each unit:
tdisch = elapsed time of discharge of each unit, with n cells, to a final voltage of
Ufinal = n× Ufinal (V).
6.11.8 The six individual capacity data, normalized to 20 °C and 25 °C for each of the five discharge rates shall be reported.
6.11.9 In the type test for determination of the actual capacity Ca preceding or following a particular test routine, the discharge shall be terminated, if not specified otherwise, when the elapsed time of discharge tdisch of each unit with n cells to a final voltage of Ufinal = n × Ufinal (V) has been recorded.
6.11.10 In an acceptance or commissioning test the discharge, at one rate only, shall be terminated when one of the following values tdisch, whichever comes first, has been recorded:
tdisch = the elapsed time of discharge of the string, with n cells, to a voltage of n× Ufinal (V)
or
tdisch = the elapsed time when the first of the unit in the string reached a voltage of
U = (Ufinal – × 0,2) in volts
with the value of ( ×0,2) as shown below, or as agreed between the battery manufacturer and the battery user. Individual unit voltages can be used to assess variability within the lot.
Table 8 – Final voltage de-rating factor in commissioning or acceptance test
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Unit voltage V
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× 0,2
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2
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1.000× 0,20V=0.200
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4
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1.414× 0,20V=0.282
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6
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1.732× 0,20V=0.346
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8
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2.000×0,20V=0.400
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10
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2.236× 0,20V=0.447
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12
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2.449× 0,20V=0.489
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16
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2.828× 0,20V=0.565
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48
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4.989× 0,20V=0.979
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EXAMPLE: In a string of eight 12 V monobloc batteries the discharge (e.g. at the I3 rate to Ufinal 1,70 Vpc) shall be terminated when a string voltage of 48 × 1,70 Vpc = 81,6 V is reached or when one of the eight monobloc batteries of the string reached a unit voltage of 10,2 V – 0,489 V = 9,711 V.
6.11.11 The measured capacity Ca (Ah) at the initial temperature q shall be calculated as the product of the discharge current (A) and tdisch i.e. the discharge time (h).
6.11.12 If the initial temperature q is different from the reference temperature of either 20 °C or 25 °C, the measured capacity shall be corrected by means of the following equation to
obtain the actual capacity Ca at the selected reference temperature:
Ca20 °C = C /[1+ l(q - 20)] in Ah or Ca25 °C = C /[1+l (q- 25)] in Ah
The coefficient ë shall be taken always as shown in 6.11.3 and according to the relative discharge rate.
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Charge retention during storage
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6.12
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6.12.1 The test shall be carried out with six cells or six monobloc batteries.
6.12.2 The test units shall be selected and prepared according to 5.2.
6.12.3 The test units shall have, before starting the test, an actual capacity Ca of at least Crt (3 h rate – Ufinal 1,70 Vpc at the selected reference temperature), and be fully charged.
6.12.4 The units shall be stored at an ambient temperature of 25 °C ± 5 K and fully disconnected from any external circuit.
6.12.5 After 180 days of storage the units shall be discharged without any prior recharge so that their actual capacity after storage Cast (3 h – Ufinal 1,70 Vpc at the selected reference temperature) can be determined.
6.12.6 The charge retention factor Crf shall be expressed as percentage, and is equal to Crf = (Cast × 100) / Ca (%)
6.12.7 The six individual values of Crf shall be reported
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Float service with daily discharges
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6.13
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6.13.1 The test shall be carried out with six cells or three monobloc batteries.
6.13.2 The test units shall be selected and prepared according to 5.2.
6.13.3 The test units shall have, before starting the test, an actual capacity Ca of at least 0,95 Crt (3 h – Ufinal 1,70 Vpc at the selected reference temperature) and be fully charged.
6.13.4 The units shall be connected to a device whereby they undergo a series of discharge and charge cycles. In case of test equipment voltage limitations, 2 V or 4 V units can be grouped together in series to form a larger voltage string. However the number of individual cycle performance data points should be kept constant.
Each cycle shall comprise:
a) A discharge for 2 h with a current of I = 2,0 I10 maintained constant within ±1 % where I10 = [C10] / [10] in A and followed immediately by
b) A charge for 22 h with a current limited to I = 2,0 I10 and a voltage limited to the float voltage specified by the manufacturer for either 20 °C or 25 °C.
c) The cells and monobloc batteries shall be operated at a temperature between 18 °C and 27 °C and the discharge–charge cycle routine a) and b) continued until, during a discharge of step a), a voltage of Ufinal 1,80 Vpc× n cells per string is reached in a time shorter than 2 h.
d) The unit or string voltages and number of cycles achieved with the discharge–charge cycle routine a) and b) shall be recorded.
NOTE This cycle number represents the amount of cycles which can be achieved in one single sequence without any prolonged charge or boost charge treatment and when the unit is subjected to a 24 h back-to-back sequence of a 2 h discharge to 40 % d.o.d (C10) followed by 22 h of charge and when recharged exclusively with the maximum charge voltage equivalent to the float voltage. This test is designed to more closely simulate the type of cycle service a battery experiences during constant voltage float service where no boost charge
mode is available. Battery manufacturer may propose a special charging routine when such a battery is used for a genuine cycle service such as in PVES, Load levelling or similar applications.
e) The units having reached the conditions outlined in c) shall then be subjected for 168 h ± 0,1 h to a charge with a current limited to I = 2,0 I10 and a voltage limited to the float voltage specified by the manufacturer for either 20 °C or 25 °C.
f) At the end of the 168 h ± 0,1 h of charge, the units shall be subjected to a capacity test with a constant current of I = I3 to Ufinal 1,70 Vpc and the capacity Caf corrected to 20 °C or 25 °C and recorded. This value Caf represents the residual capacity available when units, after numerous cycles, are then subjected to a prolonged period of charge with a charge voltage equivalent to the float voltage.
g) At the conclusion of the capacity test outlined in f), the units shall be fully charged and then subjected to an equalization or boost charge according to the manufacturer’s specifications. At the conclusion of this equalization or boost charge treatment the units shall be subjected to a capacity test with a constant current of I = I3 to Ufinal 1,70 Vpc and the capacity Cab corrected to 20 °C or 25 °C and recorded. This value Cab represents the residual capacity available when the units, after numerous cycles and a prolonged charge with float voltage settings, are subjected to a manufacturer specific equalization or boost charge treatment.
NOTE This additional test sequence is designed to generate information (Caf and Cab in % of Crt ) as to how an observed capacity walk-down is reversible either by prolonged charge or by a boost charge treatment suggested by the manufacturer for the battery under test.
The test sequence a) to g) shall be repeated until, in the steps f) and g), the test units show a capacity Caf and Cab lower than 80 % of Crt (3 h rate to Ufinal 1,70 Vpc at the selected reference temperature).
6.13.5 The test results:
a) Number of cycles achieved by each unit before reaching 1,80 Vpc during the 2 h of discharge
b) Capacity Caf expressed in % of Crt after 168 h float charge
c) Capacity Cab expressed in % of Crt after the manufacturer’s specified boost charge treatment
The number or routines a) to g) (of 6.13.4) achieved by each unit before either Caf or Cab showed a residual capacity of less than 80 % of Crt. shall be reported as the individual value of a), b), c) and d) of each unit tested and as shown (see Tables 9 and 10 below).
Table 9 – List of results of float service with daily discharges
Table 10 – Summary of results of float service with daily discharges
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Recharge behaviour
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6.14
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6.14.1 The test shall be carried out with three cells or three monobloc batteries in a single string.
6.14.2 The test units shall be selected and prepared according to 5.2.
6.14.3 The test units shall have, before starting the test, an actual capacity Ca of at least Crt (10 h – Ufinal 1,80 Vpc at the selected reference temperature) and be fully charged.
6.14.4 The string shall be discharged, with unit temperature between 18 °C to 27 °C, and a constant current of I = I10 to a string voltage Ufinal n×1,80 Vpc. This capacity Ca value shall be corrected to 20 °C or 25 °C.
6.14.5 After the discharge and a 1h ± 0,1h stand in the discharged state, the units shall be recharged, with unit temperature between 18 °C to 27 °C, with a current limited to I = 2,0I10 and a voltage limited to the float voltage specified by the manufacturer for either 20 °C or 25 °C.
6.14.6 After 24 h ± 0,1 h of charge the units shall be immediately discharged again with a current of I10 to a string voltage Ufinal n× 1,80 Vpc. This capacity value Ca24 shall be corrected to 20 °C or 25 °C.
6.14.7 The capacity found after 24 h of charge Ca24 shall be expressed as percentage of the initial actual capacity (recharge behaviour factor Rbf) as follows:
Rbf24h = (Ca24×100) / Ca %
6.14.8 The units shall be fully recharged and then again discharged, with unit temperature between 18 °C to 27 °C and a constant current of I = I10 to a string voltage of n× 1,80 Vpc. This capacity Ca value shall be corrected to 20 °C or 25 °C.
6.14.9 After the discharge and a 1h± 0.1h stand in the discharged state, the units shall be recharged with a current limited to I = 2,0 I10 and a voltage limited to the float voltage specified by the manufacturer for either 20 °C or 25 °C.
6.14.10 After 168 h ± 0,1 h of charge the units shall be discharged again with a current of I10 to a string voltage of Ufinal n × 1,80 Vpc. This capacity value Ca168 shall be corrected to 20 °C or 25 °C.
6.14.11 The capacity found after 168 h Ca168 shall be expressed as percentage of the initial actual capacity charge (recharge behaviour factor Rbf) as follows:
Rbf168 h = (Ca168 ×100) / Ca %
6.14.12 The value of Rbf24 h and Rbf168 h of the string shall be reported.
NOTE This test gives information about the recharge behaviour in terms of effective available capacity after 24 h and 168 h of a recharge with float voltage settings and avoids reliance on data like ampere hours charged back that is irrelevant to the real application condition.
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Service life at an operating temperature of 40 °C
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6.15
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6.15.1 The test shall be carried out with three cells or three monobloc batteries.
6.15.2 The test units shall be selected and prepared according to 5.2.
6.15.3 The test units shall have, before starting the test, an actual capacity Ca of at least 0,95Crt (3 h – Ufinal 1,70 Vpc at the selected reference temperature) and be fully charged.
6.15.4 The units shall be float charged at 40 °C with the manufacturer’s recommended float voltage for 25 °C.
6.15.5 The units shall not be outfitted with means of dimensional stabilization beyond that normally present in the cell or monobloc battery assembly and shown/specified in the appropriate technical documentation of the product range.
6.15.6 The units shall be placed in a hot air enclosure with such an air temperature that the monobloc batteries have a temperature of 40 °C ± 2 K. The relative humidity level of the air of the chamber shall lower than 35 % and its actual value reported.
6.15.7 Every 118 days ± 3 days the units shall, after cooling down to room temperature under float charge voltage setting, be subjected within 24 h ± 12 h to a determination of their individual actual capacity Ca (Crt 3 h – Ufinal 1,70 Vpc at the selected reference temperature).
No charge with voltages beyond the float charge voltage is admissible before or after such a capacity determination. After capacity determination, the units are returned to float charge in the hot air enclosure as in 6.15.6 for another 118 days at 40 °C. The test of a unit is terminated when the individual actual capacity of that unit is less than 0,8 Crt. The remaining
units continue to be tested until the actual capacity of each unit is less than 0,8 Crt
6.15.8 The individual capacity values Ca shall be plotted in a graph as function of days elapsed at 40 °C ± 2 K.
For each of the three cells or monobloc batteries, the intersection of the regression line, connecting the individual Ca data points, with a horizontal line representing a capacity level of 0,8 Crt (Crt 3 h – Ufinal 1,70 Vpc at the selected reference temperature) shall be determined in terms of elapsed days at 40 °C and reported as the three individual values of days elapsed.
NOTE This test gives information about the service behaviour of cells and monobloc batteries under elevated operating temperature conditions.
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Impact of a stress temperature of 55 °C or 60 °C
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6.16
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6.16.1 The test shall be carried out with three cells or three monobloc batteries.
6.16.2 The test units shall be selected and prepared according to 5.2.
6.16.3 The test units shall have, before starting the test, an actual capacity Ca of at least 0,95Crt (3 h – Ufinal 1,70 Vpc and/or 0,25h – Ufinal 1,60 Vpc) at the selected reference temperature) and be fully charged.
6.16.4 The units shall be float charged at 55 °C or 60 °C with the manufacturer’s recommended float voltage for 25 °C.
6.16.5 The units can be outfitted with means of dimensional stabilization beyond that normally present in the cell or monobloc battery assembly and shown/specified in the appropriate technical documentation of the product range. These means shall be described/shown in the test report of the product range.
6.16.6 The units shall be placed in a hot air enclosure with such an air temperature that the monobloc batteries have a temperature of 55 °C ± 2 K or 60 °C ± 2 K. The relative humidity level of the air of the chamber shall be lower than 35 % and its actual value reported.
6.16.7 When tested at 55 °C, the units shall be cooled down, every 42 days ± 3 days, to room temperature under float charge setting and subjected, within 24h ± 12h, to a determination of their individual actual capacity Ca (at the 3 h rate to Ufinal 1,70 Vpc and/or at the 0,25 h rate to Ufinal 1,60 Vpc at the selected reference temperature).
When tested at 60 °C, the units shall be cooled down, every 30 days ± 3 days, to room temperature under float charge and subjected, within 24 h ± 12 h, to a determination of their individual actual capacity Ca (at the 3 h rate to Ufinal 1,70 Vpc and/or at the 0,25 h rate to Ufinal 1,60 Vpc at the selected reference temperature). Discharges at the 0,25 h rate are useful to evaluate the impact of the temperature on performance under UPS discharge rate conditions.
No charge with voltages beyond the float charge voltage is admissible before or after such a capacity determination. After capacity determinations, the units are returned to float charge in the hot air enclosure as in 6.16.6 for another 42 days at 55 °C (or 30 days at 60 °C). The test is terminated for a unit when the individual actual capacity of that unit is less than 0,8Crt. At the 3 h and/or the 0,25 h rate The remaining units continue to be tested until the actual capacity of each unit is less than 0,8Crt.
6.16.8 The individual capacity values Ca at the 3 h rate and/or the 0.25 h rate shall be plotted in a graph as function of days elapsed at 55 °C ± 2 K or 60 °C ± 2 K. For each of the three cells or monobloc batteries, the intersection of the regression line, connecting the individual Ca data points, with a horizontal line representing a capacity level of 0,8Crt (Crt 3 h – Ufinal 1,70 Vpc and/or 0,25 h to Ufinal 1,60 Vpc at the selected reference
temperature) shall be determined in terms of elapsed days at 55 °C or 60 °C and reported as three individual values of days elapsed.
NOTE This test can give information about the service behaviour of cells and monobloc batteries under very abusive operating temperature conditions.
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Abusive over-discharge
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6.17
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6.17.1 The test shall be carried out with the number of units shown below.
6.17.2 The test units shall be selected and prepared according to 5.2.
6.17.3 The test units shall have, before starting the test, an actual capacity Ca of at least Crt (3 h – Ufinal 1,70 Vpc at the selected reference temperature) and be fully charged.
6.17.4 The unbalanced string over-discharge test shall be carried out with four fully charged cells or monobloc batteries.
6.17.5 One of the 4 units shall be discharged, at a unit temperature of 18 °C to 27 °C, with a current of I10 for 3 h and then connected to the remaining 3 fully charged units in series and with the intercell connectors giving, between each units, an air gap of 10 mm or as specified in the appropriate technical documentation of the product range.
6.17.6 This four unit string shall then be discharged, with all unit temperatures between 18 °C to 27 °C, with a current I = I10 (Ufinal 1,80 Vpc) until the voltage of the three, initially fully charged (i.e. not predischarged) units reach a total voltage of Ufinal of 3 × n ×1,70 Vpc where n is the number of cells in this substring.
6.17.7 After the discharge and a 24 h ± 0,1 h stand in the discharged state, the four unit string shall be recharged in series for 168 h ± 0,1 h with a current limited to I = 2,0 I10 and a voltage limited to the float voltage specified by the manufacturer for either 20 °C or 25 °C.
6.17.8 At the end of the 168 h ± 0.1 h of charge, the units shall be subjected, as a four unit string, to a capacity test with a constant current of I = I3 to a Ufinal of 4 × n × 1,70 Vpc and the capacity Ca corrected to 20 °C or 25 °C.
6.17.9 The capacity Ca of the string shall be referenced to the rated capacity Crt (3 h – Ufinal 1,70 Vpc at the selected reference temperature) as shown below and gives the unbalanced over-discharge Caod capacity ratio. This value shall be reported. Caod = Ca / Crt
NOTE This test is designed to yield the value Caod which represents the fraction of capacity available, after recharge, when cells and monobloc batteries with an irregular initial capacity, due to prolonged storage or similar, are subjected to a complete discharge and one week of float charge.
6.17.10 The cyclic over-discharge test shall be carried out with three fully charged units.
6.17.11 The units shall be discharged individually or as a string, with all unit temperatures between 18 °C to 27 °C and with a constant current of I = I10 to a voltage Ufinal of n × 1,25 Vpc where n is the number of cells per unit or string.
6.17.12 After the discharge and a 1 h ± 0,1 h stand in the discharged state, the units shall be recharged for 168 h ± 0,1 h with a current limited to I = 2,0 I10 and a voltage limited to the float voltage specified by the manufacturer for either 20 °C or 25 °C.
6.17.13 The sequence outlined above shall be repeated 5 times.
6.17.14 At the end of the fifth 168 h ± 0,1 h of charge, the units or the string shall be subjected to a capacity test with a constant current of I = I3 to Ufinal of n × 1,70 Vpc and the capacity Ca corrected to 20 °C or 25 °C.
6.17.15 The capacity Ca of each unit or of the string shall be referenced to the rated capacity Crt (3 h – Ufinal 1,70 Vpc at the selected reference temperature) as shown below and gives the cyclic over-discharge Caoc capacity ratio. This value(s) shall be reported Caoc = Ca / Crt
NOTE This test is designed to replicate repetitive abusive over-discharge operating conditions, which may be encountered in the field. Its listing does not intent to encourage the battery operator to routinely plan for such service conditions, but if it does occur, the subsequent performance of the cells and monobloc batteries can be predicted.
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Thermal runaway sensitivity
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6.18
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6.18.1 The test shall be carried out with six cells or six monobloc batteries.
6.18.2 The test units shall be selected and prepared according to 5.2.
6.18.3 The test units shall have, before starting the test, an actual capacity Ca of at least Crt (3 h – Ufinal 1,70 Vpc at the selected reference temperature) and be fully charged.
6.18.4 The units shall be assembled with the intercell connectors as specified in the appropriate technical documentation of the product range and the test configuration photographed and associated distances reported.
6.18.5 The ambient temperature shall be between 20 °C to 25 °C during the test and any natural airflow across the units shall be slower than 0,5 m.s–1.
Any forced airflow would enhance cooling to the monobloc batteries and thus result in an unacceptable modification of the test condition and has therefore to be rigorously avoided.
6.18.6 Temperature probes, with a resolution of 1 K and allowing a continuous registration of the temperature (interval between temperature measurements ≤0,25 h), shall be installed as follows (see also Figures 7 and 8 below):
a) One probe in contact with the surface of the case of the second unit in the string. The wall selected shall be that which is in contact with the outmost plate of the cell element and is located between two adjacent units (probe a).
b) One probe in the air in the gap inside the string (probe b).
c) One probe in the air at distance of 100 mm from the string (probe c).
6.18.7 The string shall be charged with a source of d.c. current and with a voltage as specified below. The current flowing through the string shall be monitored with an appropriate resolution and at an interval, between measurements, of ≤0,25 h.
6.18.8 The constant charge voltage, measured at the terminals of the string, shall be set to n × 2,45 Vpc ± 0,01 Vpc throughout the test, where n is the number of cells in the string.
6.18.9 The elapsed time of charge to a unit temperature of 60 °C ± 1 K, measured with the probe a) at the surface or the temperature reached after 168 h continuous charge, shall be recorded and the test stopped whichever comes first.
6.18.10 The string shall then be cooled down to room temperature in open circuit condition and then utilized for the test in 6.18.11.
6.18.11 The previously utilized string shall be charged with a source of d.c. current and with a voltage as specified below. The current flowing through the string shall be monitored with an appropriate resolution at an interval between measurements of ≤0,25 h.
6.18.12 The constant charge voltage, measured at the terminals of the string, shall be set to n ×2,60 Vpc ± 0,01 Vpc throughout the test, where n is the number of cells in the string.
6.18.13 The elapsed time of charge to a temperature of unit 60 °C ± 1 K, measured with the probe a) at the surface or the temperature reached after 168 h continuous charge, shall be recorded and the test stopped whichever comes first.
6.18.14 At the conclusion of both tests the test data shall be assembled and presented as follows:
a) Duration of charge until a unit temperature of 60 °C ± 1 K (probe a) is reached or the effective temperature (probe a) after 168 h of charge with 2,45 Vpc
b) Duration of charge until a unit temperature of 60 °C ± 1 K (probe a) is reached or the effective temperature (probe a) after 168 h of charge with 2,60 Vpc
c) Graphic or trace of the temperatures recorded by probes a), b) and c) during both test
d) Graphic or trace of string current during both test
NOTE This test is designed to allow the comparison of different cell and monobloc batteries designs under reproducible test conditions. A sensitivity to thermal runaway should be deduced not only from the time to 60 °C but also from the speed in which a temperature rise in the critical 40 °C to 60 °C range occurs together with the associated current rise and the temperature differential between battery and outside air. The test does not pretend
to replicate all conditions leading to thermal runaway.
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Low temperature sensitivity
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6.19
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6.19.1 The test shall be carried out with three cells or three monobloc batteries.
6.19.2 The test units shall be selected and prepared according to 5.2.
6.19.3 The test units shall have, before starting the test, an actual capacity Ca of at least Crt (3 h – Ufinal 1,70 Vpc at the selected reference temperature) and be fully charged.
6.19.4 The units shall be individually discharged with a current of I = I10 to an Ufinal of n ××80 Vpc at a unit temperature between 18 °C and 27 °C.
6.19.5 The discharged units shall then be placed in a test chamber with a forced flow of air having a temperature of –18 °C ± 2 K.
6.19.6 After 72 h ± 1 h of residence in the test chamber the units shall be withdrawn from the test chamber and, after 24 h ± 1 h of stand at open circuit, charged in a room with an ambient temperature between +18 to +27 °C for 168 h ± 0,1 h with a current limited to I =2,0 I10 and a voltage limited to the float voltage specified by the manufacturer for either 20 °C or 25 °C.
6.19.7 The units shall then be individually discharged with a current of I =I3 to an Ufinal of n ×1,70 Vpc and the actual capacity Ca corrected to 20 °C or 25 °C shall be recorded.
6.19.8 The capacity Ca of each unit shall be referenced to the rated capacity Crt. (3 h – Ufinal 1,70 Vpc at the selected reference temperature) as shown below and gives the Cals capacity ratio.
Cals = Ca / Crt
6.19.9 The units shall be inspected for fractures, excessive bulging or other freezing induced damages.
6.19.10 The three individual values of Cals as also freezing damage shall be reported.
6.19.11 The sequence 6.19.1 to 6.19.10 shall be repeated with a new set of units only if the previous freeze cycle resulted in a significant capacity loss or freezing damages and be modified as shown in 6.19.12.
6.19.12 These units shall be individually discharged in this second test, before low temperature exposure, with a current of I = I3 to an Ufinal of n × 1,70 Vpc at a unit temperature between 18 °C and 27 °C.
6.19.13 The test data shall be reported as follows (see Table 11):
Table 11 – Data report
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Discharged before
freezing with
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Capacity ratio Cals
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Freezing damages
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I10 to n × 1,80 Vpc
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unit 1
unit 2
unit 3
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unit 1
unit 2
unit 3
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I3 data to be shown only if previous test shows freezing damage or Cals < 0,8
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I3 to n× 1,70 Vpc
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unit 1
unit 2
unit 3
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unit 1
unit 2
unit 3
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NOTE This test yields information on the behaviour of batteries in environments with uncontrolled temperatures where power outages can cause a battery discharge with associated prolonged low temperature stand and unavailability of power for recharge.
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Dimensional stability at elevated internal pressures and temperatures
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6.20
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6.20.1 The test shall be carried out with one cell or one monobloc battery.
6.20.2 The test unit, inclusive eventual standard structural stabilizing features, shall be adapted with a pressure regulator to maintain a pressure in all interior cavities of the test unit equal to the maximum valve opening pressure present in units and as specified by the manufacturer. This value shall be measured and reported. This specified pressure shall be maintained throughout the test.
6.20.3 The maximum outside dimension (width and length) of the cell case shall be measured before pressurization and recorded.
6.20.4 The pressurized unit shall be placed into a chamber with recirculating air at a temperature of 50 °C ± 2 K.
6.20.5 After 24 h ± 0,1 h of residence in the test chamber and under pressure, the maximum outside dimension (width and length) of the cell case shall be measured and recorded at a temperature as close as possible to 50 °C ± 2 K.
6.20.6 The increase in the cell case dimensions after 24 h ± 0,1 h at 50 °C ± 2 K shall be reported both as percentage deviation from the value before the test and as measured change in mm.
NOTE This test yields information to allay battery users concerns about removal difficulties when batteries are installed in tight places.
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Stability against mechanical abuse of units during installation
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6.21
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6.21.1 The test shall be carried out with two cells or two monobloc batteries.
6.21.2 The test unit shall be selected and prepared according to 5.2 and not have any protective packing.
6.21.3 The units shall be dropped according to the height prescriptions of IEC 60068-2-32 and amendment. Two “Free Fall”, for resistance against leakages caused by two drops each onto a smooth, level concrete floor from drop heights as specified below:
Fall from 100 mm for units weighing up to 50 kg
Fall from 50 mm for units weighing between 50 kg and 100 kg
Fall from 25 mm for units weighing more than 100 kg
6.21.4 The drop test conditions shall assure, with test arrangements as shown in Figures 9, 10 and 11 below, reproducible impact points for the shortest edge drop impact and the corner impact. The two impacts, per impact type, shall be on the same corner and on the same shortest edge.
6.21.5 For the corner and edge drops, the unit shall be oriented in such a fashion that a straight line drawn through the struck corner/edge and the unit geometric centre is approximately perpendicular to the impact surface.
6.21.6 Each of the units shall be inspected, after the two consecutive drops, for gas and liquid leaks with adequate and sensitive means such as a high voltage (2 kV to 5 kV) dielectric breakdown test, helium leak detectors, hydrogen detectors, pH indicator paper and the like and the findings documented and reported.
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