diy solar

diy solar

Vestwoods 200ah one cell "severe overvoltage alarm" error?

W

Windtest

New Member
Joined
Oct 23, 2022
Messages
2
New to lithium iron phosphate. Purchased a cheap China Vestoods battery. First battery worked fantastic fell in love, after a month or two bought two more.

Both new batteries show one cell overrunning voltage just before complete charge on other three cells. 3.855 versus 3.355.

Bluetooth BMS Screenshot_20221022-121218_Video Player.jpgshows charge MOS disconnecting due to "serious cell Over voltage" error.

EBay vendor says this is normal but does not sound right to me? Any thoughts?
 
Knock your charge voltage down half a volt or so, so that the #1 cell cannot go that high, hopefully then the BMS can manage and complete the charge and balance cycle. It looks like it might have a good BMS, can go series and parallel to a useful sized bank.
Also hopefully the battery will even out over a few cycles.
 
Last edited:
Supervstech said:
It shows the builder didn't g
Supervstech said:
It shows the builder didn't get matched cells in the pack.
Results of a cheap battery.
It is surprising you have access to the bms on one.
Pics?
Click to expand...

et matched cells in the pack.
Results of a cheap battery.
It is surprising you have access to the bms on one.
Pics?
Click to expand...
 

Attachments

  • Screenshot_20221023-082852_eBay.jpg
    Screenshot_20221023-082852_eBay.jpg
    234.6 KB · Views: 14
How do you even stay in business like this?

I mean allowing a cell to go up to 3.844v before tripping?
And then allowing the user to see that with the app! Any googling shows that this is a bad thing.

If that value is actually true, then at least don't provide the user with an app to see it!

Then the mind reels - what if the bms voltage sensor is wrong, and the batts are actually all right? But the bms trips and doesn't allow for a proper balance ...

I mean, how is the user ... .supposing something else ... might be ok...but maybe not ... MY MIND IS MELTING.. :)
 
My 250 ah ultra has one cell at .8 volts and the other 3 at 3.7, charged it once, discharged @ 30 amps for 4 min twice and got low voltage protection and over voltage protection turned on at the same time. Discharge and charge are both turned off. Now they want me to pay $150 to ship it back.
 
Alkaline said:
how did you figure this out?
Click to expand...
Won't charge , cell at .211volts set my power supply to 3.6 and the bad cell won't take a charge. It happens, Vestwoods did right by me, sent a new battery and told me to dispose of this one. Couldn't ask for more from yhem.
 
They use cells I've never seen before, long flat with a 4 screw plate on each end. Looks like a solid bms, has balancing and dual temp sensors, looks like it to starts balancing at 3.4 , that's when the Led's on the bottom of the bms start lighting up. Cells are compressed using metal strap, held in the case using foam. Large case. Lots of room for what ever else. Looks like it has a circuit breaker as well. I jumpers a 280ah Eve cell I had and charged up the battery at 40 amps, charged fine rest of the cells were within 20mv of each other. I just think they got a bad cell.

UPDATE: Got the replacement battery, charging it now, all the cells are running within 20mv of each other. It arrived about half charge.
 

Attachments

  • 20230912_134154.jpg
    20230912_134154.jpg
    952.4 KB · Views: 19
  • 20230912_134150.jpg
    20230912_134150.jpg
    1,016.1 KB · Views: 20
  • 16947162899537199033689349982503.jpg
    16947162899537199033689349982503.jpg
    730.7 KB · Views: 17
Last edited:
That looks.... horrid.. sorry my guy I think you got some questionable grade cells in there. Did you buy these from Amazon?
I haven't seen that shaving cream stuff in a battery for a while, this was circa 2018.
 
You must log in or register to reply here.
Back
Top