Lead-Acid Battery Capacity Tester

Hi All,

I am looking for methods to test battery reserve capacity of Lead Acid Batteries of 12 Volt of upto 200AH. Following are links of some commercial models :

Battery Tester Options Lead Acid, VRLA, AGM, SLA, 12 volt, 6 volt,
ZTS Lead Acid Multi-Battery Tester™ (MBT-LA2)
**broken link removed**

These products rapidly test the battery capacity without discharging it fully. It is not only an AC conductance test but a series of other measurements.

I am seeking ideas and insights into this. Rapid and accurate battery reserve capacity detection, -- HOW TO --

Thanks for reading

Best Regards
andig

I think they work by applying a high current load for a short period of time and calculating the batteries internal resistance based on the voltage drop. This can be correlated to battery health.

As part of an aircraft annual inspection, you are supposed to do a reserve capacity test. I built a computer-controlled tester, utilizing a DOS-only 286 laptop that works fine for me. I use a discharge current (~35A) which is close to the average load in my aircraft if the alternator trips off line. The goal is to show that the battery capacity is sufficient to get you on the ground before the electrons run out.

Dear ronv and MikeML

Thanks for the reply. High current load based discharge for short time does give SOC (State of Charge) result but SOH (State of Health) still remains doubtful. The goal is to find for say a battery of 100AH capacity, whether it is capable of delivering the rated capacity. Battery conductance is normally measured by passing an AC current through it. As MikeML mentioned although a heavy discharge load could be used to determined in case of Automotive application that if it can crank up enough juice for the self starter still total capacity remains questioned.

My application is for standby battery as used in UPS system for early detection of ageing batteries.
Regards