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Old 01-19-2012, 01:45 PM   #1 (permalink)
Daox
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Max sustained amperage from lead acid batteries

I was talking with Darin today about my battery electric riding mower which I recently got the snowblower attachment working on (pics & video here). He had a concern that I was pulling too many amps continuously. The concern is not for the motor (which doens't heat up at all in the winter), but for the batteries. They are flooded lead acid 150Ah group 31 batteries (4). During normal mowing I probably pull about 80A, so .5C for about a half hour. However, while snowblowing I'm probably pulling much more at times. Darin seemed to remember that with lead acid there is a rule on how long you can pull .5C, 1C, 2C etc. like there is for lithium batteries. I've never heard this, but it made me wonder. He couldn't remember where he read this, so we decided to post here and see if anyone knew anything?

Obviously the peukert effect is magnified quite a bit at higher C rates, but capacity isn't an issue as I just recharged the mower and only put 1kwh (from the wall) into the 7kWh pack.

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