new bms volt check

[csjones10d]

hi I have just fitted a new bms to my battery as the other blew, iv done a single sell check and bellow is the volts of each sell I don't think it is working right as 3 of the sells are lower than the rest what do you think and what should I do as I am trying to sort out this battery through advice from here as I know nothing about this subject and I am just leaning

sell

1 - 3.3
2 - 3.3
3- 3.5
4 - 3.6
5 - 3.4
6 -3.5
7 - 3.5
8 - 3.5
9 - 3.6
10- 3.6
11-3.6
12- 3.5
13- 3.6
14- 3.6
15- 3.6
16- 3.5

so I see sell numbers 1, 2 and 5 are low any advice would be great


thanks chris

 

[999zip999]

Hello Chris welcome to E.S. More info on your battery would help a link of where you got it or pics.
I guess it's lifepo4 as posted 16s. I like to first balance the battery to help the Slow balance circuit of the bms. I use a 3.6v voltpheaks single cell charger. You can use a little charger for a cell phone ect. They say what voltage they could provide ? That means nothing Check it. Printed 3.6v may be 7volt. You want 3.6v if not you can Sit and watch it, by sitting next to it and monitor it. Very important. 3.3v is the meat of state of charge of lifepo4 3.4v is 80% full 3.45v is 90% full so after 3.45v it will race upward to 3.6v so you must sit and watch closely. Not to go over 3.6v .

 

[wesnewell]

Leave it on the charger 12 hours and then measure the voltages again, but to a hundredth of a volt minimum. If the bms is working properly, the cells should start to balance out better.

 

[dnmun]

hi I have just fitted a new bms to my battery as the other blew, iv done a single sell check and bellow is the volts of each sell I don't think it is working right as 3 of the sells are lower than the rest what do you think and what should I do as I am trying to sort out this battery through advice from here as I know nothing about this subject and I am just leaning

sell

no, buy!! buy buy buy!

measure the output voltage of your charger using the 200V DC scale, then plug in your battery and measure each channel while it is charging using the 20V DC scale. while charging.

what was wrong with the other BMS and why did you not just use it?

 

[999zip999]

A guess it's been sitting and the bms uses the number 1 and 2 cell and time has sucked them down. What, what how many guesses do I get ?
Pre charging the two cells speeds up the balancing process. Be careful it's very much alive. Like a snake with a exploding spark for bite.
Charging to 3.5v is fine.