Doinit said:No relationship at all... not even if the voltage is at its resting voltage?
Doinit said:None of the cells are bad tho is what Im saying since they all have equal voltage .....
Doinit said:What kind of load could I use for the 60v battery..
Doinit said:Is it safe to assume that none of the individual cells are bad (less capacity than the others) if they all have the same voltage?
I was thinking that maybe the entire module could have low capacity but i thought if all the cells voltages match after resting that all the individual cells are of similar capacity
Doinit said:I was thinking that maybe the entire module could have low capacity but i thought if all the cells voltages match after resting that all the individual cells are of similar capacity
Doinit said:Like for instance I cant power a regular house light bulb directly off the battery.. its 60v not 120v
Doin it said:If the capacity of an individual cell (while there isnt any charging or discharging and battery has rested) is different than another cells capacity in the same module then will that individuals cell voltage be different than the other cells voltage?
Doinit said:If the capacity of an individual cell (while there isnt any charging or discharging and battery has rested) is different than another cells capacity in the same module then will that individuals cell voltage be different than the other cells voltage?
Doinit said:Ok I got ya Sean.. so this is why I cell needs to be tested while being discharged and charged to confirm capacity-health of the cell....?
Korishan said:It is impossible under standard load conditions for cells in parallel to have different voltages. Voltages will always balance out with the other cells in parallel.
CrimpDaddy said:1) I completely agree with what @Sean is saying... cell voltage has no relation to cell health, capacity, quality, or even the actual balance levels. You could have a small pack with uneven capacity cell groups, and balance that battery at one specific voltage. The battery will be balanced and have the same voltage at that one specific state of charge. For example a common would be a top balance, or a bottom balance.
2) Testing (Hobby charger, constant current load and timer, power analyzer / watt hour counter.) If you cant find a resistor load or something to load up with 60v, you would always get a DC-DC step down and use something else too.
These little inline Watt Meter & Power Analyzer things that cost<$20are awesome... great for testing randomthings, but I forgot what its max supported voltage it. Might stop at 60v
The Victron Battery Monitors are also good options if you need / want something like this anyways.
https://www.victronenergy.com/battery-monitors
If you an break out the cell groups, a RC charger like this would also work well... my preferred method as it also allows you to balance the pack. Not instructional, but this is how I was testing my EV modules... just to give you an idea of what type of info you might see with a charger. This would could do20stotal, assuming I can break it out into two 10s cell groups.
Electronic DC Load (not a bench power supply) has also been a great tool for battery work. Here I have an 8 amp load on this PCB for testing. BattGo to monitor cell groups.
Hope that gets the creative juices flowing. Lots of ways to do this.