Disaster!!! Or, learning the expensive way...

[codfish]

I suppose I will have to get some sort of manual charger. And try to get them to the charging threshold...

Also, I do have a battery tender. Could I try trickle charging it? I assume it’s for a 12v battery though.

I'd split it into two 12v packs, wire those in parallel, and put the Battery Tender on it.
At even 1 amp you can start those ions shuffling back in the right direction. It will sit at the starting voltage for a Very long time, but if the cells are OK, then you would eventually fully charge the 12v pack. I've done it with these 280ah cells using a Battery Tender (with lithium setting). If you don't have some way of monitoring individual cells then stop if it ever gets in the middle of the range, say 13.2 V.

 

[shaymcquaid]

Ok. Here is where I am:

Broke the banks down to 12v blocks.
(Took individual cell readings) All over the place. I’ll make a diagram tomorrow))
Cells were as low as 1.5v and as high as 3.35. (wth?)

Zapped the 12v blocks with an lead acid charger @ 40A (no settings on charger).
Cells took the amps like a thirsty camel.
Stopped the charge @ 12.2 volts.
Have dissembled the blocks and the raw cell voltages are between 2.57v and 2.8v.

I am recording voltages and will try to figure out my cell balancer tomorrow.

I am cautiously optimistic.

What are the symptoms of damage I should look out for?

I ordered they load tester that Will uses. I’ll definitely know more then.

More info tomorrow. I’m beat up.
Thanks for all who contributed ?

 

[MisterSandals]

I am recording voltages and will try to figure out my cell balancer tomorrow.

I am cautiously optimistic.

What are the symptoms of damage I should look out for?

See if the cells self-discharged overnight. Record voltages again. If they hold the voltage that you recorded today, i'd be cautiously optimistic too.

 

[shaymcquaid]

16 hours later:

ALL CELLS ARE HOLDING CHARGE PERFECTLY!!!

Can this mean I could have dodged a bullet?
What should my next steps be?

Thank you all

 

[solardad]

@shaymcquaid Awesome that the cells are back but I would be all over the inverter to see why it did not respect the low voltage shut down setting. Bum inverter, poor programing when it was 1st setup, etc...? A BMS should not be your 1st list of defense, it should be your parachute I believe. If you have a product that is not working as expected I think you are rolling dice with some other issue that could pop up.

 

[John Frum]

16 hours later:

ALL CELLS ARE HOLDING CHARGE PERFECTLY!!!

Can this mean I could have dodged a bullet?
What should my next steps be?

Thank you all

1. Capacity test the batteries.
2. verify that the inverter low voltage cutoff
3. if you have dc loads they also should have a low voltage cutoff device
4. Think about a bms even if its only used to balance the cells.

 

[shaymcquaid]

Thanks again for all of your help!

As stated, cell voltages are still rock solid after 20 hours.
I couldn’t get my cell balancer to behave, so I just broke down the banks and made a long conga line of cells in parallel and will give them a day or two to equalize.

Capacity tester will be here in a week.

 

[Sojourner1]

Out of curiosity what voltage are they holding at now?

 

[shaymcquaid]

3.208v-3.217v s l o w l y equalizing.

Difference of .009 at this hour.

 

[MisterSandals]

I hope you labeled your cells. The one that got down to 1.5v will be interesting to watch.

 

[LukeVader]

Thanks again for all of your help!

As stated, cell voltages are still rock solid after 20 hours.
I couldn’t get my cell balancer to behave, so I just broke down the banks and made a long conga line of cells in parallel and will give them a day or two to equalize.

Capacity tester will be here in a week.
View attachment 12347

Who did you get the tester from? I ordered mine quite a while ago and I'm still waiting.

 

[shaymcquaid]

Amazon. It’s thank makerhawk branded one will uses sometimes.

 

[shaymcquaid]

Good morning ☀
Cells have equalized @ 3.216v or 3.217v

I will check periodically through out the day and keep an especially close eye on the cells that suffered the deepest discharges. (Yes,I labeled them?)

I’m pretty hopeful that maybe I didn’t completely dork my bank. I reckon the capacity test will tell the tale.
I really wish I would have done a capacity test base line. Live and learn.

 

[Sojourner1]

With them sitting just equalizing It would be hard to tell if one is damaged, you will see once you put a load on them if a cell is struggling within the entire pack. Or atleast that's what I imagine.

 

[MisterSandals]

Live and learn

Good judgement comes from experience. Experience comes from poor judgement.

 

[shaymcquaid]

Good Sunday everyone.
Been putting up walls in my skoolie today.
Haven’t monkeyed with the cells.
They just sitting there chillin and waiting on the load tester and BMS (s) to get here.

The voltage has decayed.
The range is 3.205-3.223

 

[Delta-V]

I think that's promising. That's a mild drop considering the circumstances. Even with my 16 good cells I see a similar settling like this after they rest for a while.

 

[iceledoar]

What is the voltage of your panels at the mpp?

 

[shaymcquaid]

No PV panels yet.

 

[iceledoar]

No PV panels yet.

so 0vdc...lol