Acceptable Delta

Brett V

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I top balanced and was extremely careful building the battery. These are 230 amp EVE cells in a straight 16s configuration. I'm seeing an average .005 - .007 cell delta, with #1 usually being the low cell. In normal practice, is this considered acceptable?
 

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A delta of 5mv at 3.30x volts is fine.
Its the high and low knees where you will find out how good your top balance is and how well your cells match.
Especially with non trivial current flow.
Since you did a meticulous top balance and battery assembly, your cells should be well synchronized into the high knee at significant amperage.
I suggest you test that.
Also discharge with significant current until the first cell drops off the cliff.
That will characterize your pack and its bandwidth.
 
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Brett V

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Charger is set to 40 amps. The voltage starts to shoot up once the cells pass 3.4 volts. Current is beginning to drop.
 

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Brett V

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Just seconds before the charger switched to float voltage.
 

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Brett V

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Is temperature sensor 1 the bms itself?
Sensor 1 is actually taped to the black leads off the bms. Sensor 2 is through a hole in to a plastic box outside of my battery box, and sensor 3 is taped to the side of one of the cells.
 

Brett V

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I attached a small project box to house the shunt meter.
 

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Sensor 1 is actually taped to the black leads off the bms. Sensor 2 is through a hole in to a plastic box outside of my battery box, and sensor 3 is taped to the side of one of the cells.
You might want to check for hot-spots on the joinery all around the circuit.
 

Brett V

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This is where the cells landed just minutes before cutoff on a deep discharge. I hope to not normally take the pack this low...
 

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