Battery Tester

[TheBikeMan]

Hi,
Does anyone have experience with any ebike battery testers? I've got SkyRC and Nitcore gear to test individual cells but i'm looking for something that will take an 8, 10, 12, 14s systems. I would like one that will charge and discharge each cell and measure each individual cells performance, resistance etc... I've looked at the BA500 but there is little positive info on it and some negative. Surely considering the need, there must be not only a market for this kit but a few companies making things like this. Any ideas?

 

[soundwave]

 

[Sturmey]

Hi. I use to 'load test' large 50 volt lead acid batteries when I worked for the phone company. I presume the same principles could apply to test any battery.
To test a battery then, you need a suitable load (e.g. resistance wire), an ammeter,voltmeter and a clock.
So, for example, if I wanted to test my 36 volt battery at say (nominally ) 10 amps, I would make up a 3.6 ohm load that can handle over 360 watts (put the resistance wire into a bucket of water to keep it cool if necessary) etc.
After fully charging the battery and a rest period, the battery is connected to the load via the ammeter and allowed to discharge. The times are noted, along with the current and voltage readings at say 10 minute intervals and the battery is taken to be discharged when the battery voltage drops to say 28 volts.
From the readings, the capacity of the battery can be calculated.

It would also be great if the voltage of the individual cell groups could be taken during the discharge test, but this may involve opening the battery The test is usually stopped if there is a serious imbalance in the battery (i.e. one cell group voltage high/low relative to the others), as this points to a problem and no cell group should be allowed fall below 2.7 volt

 

[TheBikeMan]

Thanks Sturmey. Yes I want something that can test the individual cell groups up to 52V so it will have to have inputs for BMS plugs up to 14S. The RC charger I have now goes up to 6S but ebike batteries really start at 8S so it can't be made to do the job.