FLBikeDude
10 mW
- Joined
- Aug 26, 2013
- Messages
- 24
So I have this battery made with Headways...
16s,2p - 38120L cells
The pack has been "fine" for over 3 months, when all of a sudden a group of parallel cells just crapped out.
The cells have been previously charged about 50 times with no issues whatsoever.. i.e. Perfectly balanced to 3.60-3.68v each..
I've hit LVC on the BMS only twice and the cells were still very well balanced (within .2v of each other, e.g. The last time I hit LVC, ALL the cells were in the 2.7 - 2.9 range) 20.3 AH used at 1C or less 15-18a
One group of cells died (2p) so I removed them...
I ordered 2 new cells.. Should be here in about a week..
In the mean time I am charging with a 12v Charger... 2a
Well last night I wasn't paying attention and one 4s group of cells were all charged to 3.9v (charger makes a small noise when it shuts off (normal operation) at 15.6v and I immediately checked the voltage on the cells and they were all at 3.85 - 3.90v and all dropped to 3.60-3.70 within a min or so...
The only question I have is..
How badly did I damage the cells..
I know the charging drops from 2a to about 650ma when it hits 14.8v
16s,2p - 38120L cells
The pack has been "fine" for over 3 months, when all of a sudden a group of parallel cells just crapped out.
The cells have been previously charged about 50 times with no issues whatsoever.. i.e. Perfectly balanced to 3.60-3.68v each..
I've hit LVC on the BMS only twice and the cells were still very well balanced (within .2v of each other, e.g. The last time I hit LVC, ALL the cells were in the 2.7 - 2.9 range) 20.3 AH used at 1C or less 15-18a
One group of cells died (2p) so I removed them...
I ordered 2 new cells.. Should be here in about a week..
In the mean time I am charging with a 12v Charger... 2a
Well last night I wasn't paying attention and one 4s group of cells were all charged to 3.9v (charger makes a small noise when it shuts off (normal operation) at 15.6v and I immediately checked the voltage on the cells and they were all at 3.85 - 3.90v and all dropped to 3.60-3.70 within a min or so...
The only question I have is..
How badly did I damage the cells..
I know the charging drops from 2a to about 650ma when it hits 14.8v