Lithium 58V battery Charger -Adjusting Voltage

[jeffro22]

took a shot on a different style charger off ebay . Seller said it could be adjusted down to 58V for my Leaf packs, but I cant seem to get it below 60v. I found 2 trim pots and have made all the adjustments allowed by these but when I test with a voltmeter I am between 60-62v

I know I should probably buy the charger that was recommended off amazon and be done with it but is there anything I am missing with the one I already have?

[Sergio]

Post a picture of the charger board (...I see you updated with the picture).

Did You count the turns and put the trimpots back to where they were?

One of those likely controls the maximum power or finishing current so You need to be careful to put them back if you did not measure a difference.

[Sergio]

Not W1 (the one on the close-up photo), but the other trimpot near where the DC power output to the charger is connected.

Without a load (DC side unplugged), mark the location (take a good photo) and turn the trimpot counterclockwise a couple of turns while measuring the output voltage.

[jeffro22]

ok thanks,

i can get voltage to adjust but cant get it any lower than 60.2v. the pot only has a one 360* turn. It will go up to 62v and down to 60.2

[Sergio]

Then send the charger back since the label says "58.8v", it is obviously out of spec if the lowest voltage is 60.2v.

Make sure Your meter is reading correctly, at least try putting new batteries on the meter or using a different meter to verify the voltage reading.

Also make sure your turn the trimpot very very slowly since the 1 turn model has a much less granular change than the multi-turn model of the same value.

[jeffro22]

Originally Posted by Sergio

Then send the charger back since the label says "58.8v", it is obviously out of spec if the lowest voltage is 60.2v.

Make sure Your meter is reading correctly, at least try putting new batteries on the meter or using a different meter to verify the voltage reading.

Also make sure your turn the trimpot very very slowly since the 1 turn model has a much less granular change than the multi-turn model of the same value.

Kind of what I was thinking. Seems to far out of spec. If it was actually putting out the specified 58.8v then I should be have had enough adjustment to get it to 58.0

Although I guess I should verify that my meter is reading correctly

[jeffro22]

Apparently my voltmeter was out of spec. Bought a new one and with the trim pot adjusted down now I am reading 58.1v

[Sergio]

Originally Posted by jeffro22

Apparently my voltmeter was out of spec. Bought a new one and with the trim pot adjusted down now I am reading 58.1v

Good news but I personally think 4.15v is too high of a charging voltage unless you need all the capacity you can get out of the pack.

According to batteryuniversity data for every 0.10V drop below 4.20V/cell charge it doubles the cycle life expectancy of the pack.

I am currently charging mine to 4.05v but may lower it to 4.0v as I evaluate the Regen brake intensity after a full charge a little longer and get a better feel for how long the charge lasts for my driving/use conditions.

[jeffro22]

Originally Posted by Sergio

Good news but I personally think 4.15v is too high of a charging voltage unless you need all the capacity you can get out of the pack.

According to batteryuniversity data for every 0.10V drop below 4.20V/cell charge it doubles the cycle life expectancy of the pack.

I am currently charging mine to 4.05v but may lower it to 4.0v as I evaluate the Regen brake intensity after a full charge a little longer and get a better feel for how long the charge lasts for my driving/use conditions.

Thanks. So you are thinking 56 v is the ideal charge for max battery life?

[jeffro22]

sergio, I am trying to understand this correctly, but if I have the BMS set to cutoff the charge at 57.4V (high cell voltage set to 4.1) does it matter (within reason) what the charger is set too ? (other than maybe having 2 fail-safes on the HV,)