Well I almost burnt the house down. Time to ask for some help....

GeorgeV7

New Member
First of all, I'm new to this. I'm posting in the the beginners area hoping not to be overrun with messages about how dumb I am.

I watched dozens of Will's videos and thought I knew enough. I put up the solar panels and bought a very expensive brand new 32 cell 48v lifepo4 battery and a good solar charger.

The cells came certified fully balanced and since they were brand new all I did was check the voltage and they were all the same. Also I thought if everything is new and balanced you don't need a bms. So hooked up the charger and everything looked good.

I left it for a while and came back an hour later to find one cell with HUGE bulges on both sides and was so hot I couldn't touch it. My kids were home so thank God it didn't explode.

Obviously I shut everything down and took it outside with a pair of gloves. Now the other cells are reading different voltages too.

I'm devastated. I don't know what to do, how to fix this, or even what I did wrong and I think i ruined my $4000 battery.

I don't know what happened or what to do now. Any help would be sooo appreciated.
 

Attachments

  • Screenshot_20200606-201035_Gallery.jpg
    Screenshot_20200606-201035_Gallery.jpg
    92.4 KB · Views: 410
Last edited:

PsychoticEpisode

Solar Addict
Never build a battery with no BMS, the bms will keep the battery for over charging and bulging on you. The solar controller will not know when to stop charging the battery that is what the BMS is for. See if you can maybe return the cells as defective, then get new cells and a BMS and try again. If you cant return them then get a BMS and see if they can be saved.
 

Sojourner1

Itinerant
Never build a battery with no BMS, the bms will keep the battery for over charging and bulging on you. The solar controller will not know when to stop charging the battery that is what the BMS is for. See if you can maybe return the cells as defective, then get new cells and a BMS and try again. If you cant return them then get a BMS and see if they can be saved.
Solar controller will know when to shut down or go to float, that's what the settings are for. What it won't know is what the cells are doing.

OP, what was your settings? Did you top balance the cells?

To all new folks just because the cell are matched as they sit with no load on them (either charge or discharging) doesn't mean they'll be that way in the knees when charging or discharging, as can be seen in photo all cells aren't perfectly match.

Not the end of the world it will just cost you to replace the cell or cells.
 

Sojourner1

Itinerant
The cells came certified fully balanced and since they were brand new all I did was check the voltage and they were all the same. Also I thought if everything is new and balanced you don't need a bms. So hooked up the charger and everything looked good.

Now the other cells are reading different voltages too.

That cell really expanded and didn't pop it's blow hole.

Video time... put it in the middle of the yard and keep charging it for the blow hole venting. I haven't seen any aluminium cells overcharge/ venting videos. ;)

What are the other individual cells reading now?
 

GeorgeV7

New Member
Thank you for the replies. The charger is the Victron Smartsolar 250/100 for 48v. The cells were 2 groups together in parallel with 16 cells in series each group. I didn't make any changes to the charge controller's settings other than to set it for 48v and lifepo4.

The cell that blew up was the 2nd one in one of the groups.

So I guess they weren't really balanced from the store then? I need to too balance them by putting the rest of them in parallel? Can I still use the battery with the cell missing?
 

GeorgeV7

New Member
That cell really expanded and didn't pop it's blow hole.

Video time... put it in the middle of the yard and keep charging it for the blow hole venting. I haven't seen any aluminium cells overcharge/ venting videos. ;)

What are the other individual cells reading now?

Some are the same voltage and some are a little different. 3.32 3.35 3.4 etc.
 

Sojourner1

Itinerant
If they are in that range that's not bad at all. No cell deformities in the rest of the cells? If not break them down in parallel and top balance them.
You do know how from Wills video? Order a replacement cell, bms.
 

GeorgeV7

New Member
If they are in that range that's not bad at all. No cell deformities in the rest of the cells? If not break them down in parallel and top balance them.
You do know how from Wills video? Order a replacement cell, bms.
Ok. What bms do I get? I'm only confused because the ones I see on his site say 16s - but I have a 32 cell battery (16 in series + 16 in series) well, 15 now.
 

GeorgeV7

New Member
A cell that did that in an hour while the other cells stayed in the 3.3v range was either very defective or (dare I say) connected backwards.
Oh ok, it was absolutely not backwards. I guess it was defective but it came from China so Im just out the money I guess.
 

Supervstech

Administrator
Staff member
Moderator
From your description of the design, and the charger settings, that cell must have been near full, and others were much lower.
what voltage were all the cells at when they arrived?
 

Dzl

Unofficial Forum Librarian
Staff member
Moderator
First of all, I'm new to this. I'm posting in the the beginners area hoping not to be overrun with messages about how dumb I am.

I watched dozens of Will's videos and thought I knew enough. I put up the solar panels and bought a very expensive brand new 32 cell 48v lifepo4 battery and a good solar charger.

The cells came certified fully balanced and since they were brand new all I did was check the voltage and they were all the same. Also I thought if everything is new and balanced you don't need a bms. So hooked up the charger and everything looked good.

I left it for a while and came back an hour later to find one cell with HUGE bulges on both sides and was so hot I couldn't touch it. My kids were home so thank God it didn't explode.

Obviously I shut everything down and took it outside with a pair of gloves. Now the other cells are reading different voltages too.

I'm devastated. I don't know what to do, how to fix this, or even what I did wrong and I think i ruined my $4000 battery.

I don't know what happened or what to do now. Any help would be sooo appreciated.

Who did you buy from? Can you post a link?

I have a couple questions:
You referred to your 'battery' a few times, in my experience people who purchase raw cells more often refer to cells, packs, banks in this context. This (combined with your comment that the cells were 'certified fully balanced') makes me wonder if they were sold to you as a packaged battery? If so maybe you have more recourse, at least its worth a try.

What exactly do you mean 'certified fully balanced'
 

pierre

Somewhere down South
Ok. What bms do I get? I'm only confused because the ones I see on his site say 16s - but I have a 32 cell battery (16 in series + 16 in series) well, 15 now.
I would suggest 2 x 16S BMS's . Run each series bank on its own BMS. At least if you lose one bank you are still in business and you have better control over each cell. I agree , a BMS is essential and maybe this tragedy could have been mitigated by a properly set up BMS.
 
Last edited:
Top