Battery Cell Load Testing...Load Wattage?

Use a standard H2 halogen headlight bulb in the highest wattage you can find. Wire both high and low beams together, but 60/55 W will work satisfactorily.

6.0 V is safe, although you can go as low as 4.8 V with relatively low risk. You will need charger to charge them back up to 7.2-7.4 V as well.

 

couple of simple questions:
1. using the car light bulb at 55 watts only puts a load of 7.5 amps. I know this is the standard protocol. but isn't this too high of a load?
2. I thought the real life load for the entire battery was 200 watts which equals about only 1 amp per module.
3. am I missing some basic math here? please help with the math

 

By definition, a load test puts load on a "circuit" for a fixed amount of time - (typically 2 minutes on most threads I've seen). You record the initial voltage, apply the load, then record the voltage at the end of 2 minutes, just before removing the load.

Generally, you aren't using the bulb to completely discharge the modules. So you aren't worried about minimum voltage during the test.

Using a hobby charger to cycle the modules, I have gone down to 6V, then 5V if needed, but that was 1.5-2A, "clamped" in the mounting frame, while constantly cooled by low fan pushing air through the bottom duct.

I'm not sure what "math" you're referring to. The HV pack can charge or discharge at 20A for quite a while. For a few seconds I have seen 100A+ charge and 160A+ discharge. Multiply that by the battery voltage equals a whole bunch of watts.

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That got addressed in the other thread, just by clarifying that in a series-wired battery, each module sees just its 'share' of the total voltage, but the full total current.