How to test a Lead Acid Battery

Using the ACT 612 Intelligent Battery Tester for 6V and 12V standby SLA, cyckic GEL and WET batteries

  • Visually inspect each battery for any sign of damage or leakage. Recycle if found to be defective.
  • Allow new-out-of-the-box batteries to acclimatize overnight to room temperature 20 – 25C 68 – 75F in order to verify stated Ah capacity.
  • Verify battery voltage is above 6.35V min and 6.50V max for 6V batteries, and 12.70V min 13.00 max for 12V batteries using a calibrated Digital Volt Meter.
  • Check that the ACT 612 test lead sockets are thoroughly clean using a suitable cotton bud dipped in PCB cleaning fluid.
  • Connect battery tester to battery terminals making good tight connections in accordance with the operating instructions.
  • Set calibration adjustment to ‘0’ (6 O’clock) for generic C20 rated standby SLA batteries, 9 O’clock for cyclic C10 rated GEL batteries and 3 O’clock car WET (Flooded) batteries.
  • Record battery voltage reading obtained. Above 6.35 (6V) and 12.70 (12V) the maximum Ah capacity available in the battery will be obtained. (If battery voltage is above 7.00 (6V) and 14.00 (12V), apply a load to reduce overcharge surface voltage from battery).
  • Record Ah reading available in the battery. Repeat test twice to verify Ah reading obtained. If significant fluctuations occur, recheck connections both to meter and battery terminals.
  • When connected to the battery in accordance with the instructions, the Ah reading obtained is based on (a) battery voltage (b) battery temperature (c) battery resistance.
  • When performing accuracy comparisons between ACT 612 and ACT GOLD PLUS Intelligent Battery Testers, carefully unplug leads from one tester to another and DO NOT DISTURB TEST LEADS CONNECTED TO BATTERY.

IMPORTANT: When testing new-out-of-the-box batteries, verify that the date code stamped in the battery does not exceed 6 months from the date of manufacture and that the battery voltage is above 6.35 (6V) and 12.70 (12V). Batteries older than 6 months and below 6.25 (6V) and 12.50V (12V) must be re-charged before use or returned to your supplier as not fit for purpose. Installing a new old-stock or discharged battery to your equipment could result in costly repeat call outs and/or system failure.

SPECIAL NOTE: The generic battery software employed in the ACT 612 and previous ACT GOLD PLUS models are identical, however differences in the physical design and construction may show slight variations in Ah readings obtained (see operating manuals for relative specifications).

USEFUL TIP: To test stock of standby SLA, cyclic GEL and car WET generic batteries of different Ah capacities adjust the Calibration Control according the the above instructions. To test stock to a specific brand and Ah capacity, select a new out-of-the-box battery which is fully charged and at room temperature (as specified above) and after marking it up as your master battery, adjust the ACT 612 / ACT GOLD PLUS Calibration Control to the stated Ah capacity on the battery. You can now verify all stock of the same brand and Ah capacity has the same, above or below available Ah capacity. Remember, no two batteries are identical due to variations in component construction and internal resistance (up to +/-20%).

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