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Huge lithium degradation

I am searching and I can't find that BMS model number online anywhere ? Typo?

Can you provide a link to it?
 
robbob2112 said:
uhm

Not one single link to the product - so if you were talking to me ... try not to be a smartass
Click to expand...
The subject of my "not replying to anyone in particular" post, was not about a link. It was about how easy the search function is able to find the post within this thread. Try to be less sensitive.
 
Well, now I’m pretty convinced that the BMSs are trash, and more than likely the cells are permanently damaged.


I had been slowly rising the voltage of the power supply. I came home today and went to raise the voltage up another 0.05 volts to 14.15. Well, before I raised the voltage up, the amp output was showing 0.005 amps which is considerably lower than the 0.015 amps it has been at. So, I checked the cell voltage and found a cell on one battery at 3.78 volts!! I didn’t even bother checking the other ones after that. I’m done with this setup. I’m going to hang on to it all till I can get replacement batteries. After that I’ll probably scrap the cells that have been charging at too high of a voltage, and get a different BMS.


I just can’t rely on a BMS that doesn’t balance the way it should. Maybe this was just a bad batch of them because they do have a good reputation.
 
jorby said:
The subject of my "not replying to anyone in particular" post, was not about a link. It was about how easy the search function is able to find the post within this thread. Try to be less sensitive.
Click to expand...

perhaps pointing out an obvious feature that everyone is aware of and knows how to use isn't being a smartass, or being sensitive... I've attached a report for reference and if you don't stop I will be forced to fill it out and turn it in on you
 

Attachments

Last edited:
91cavgt said:
Well, now I’m pretty convinced that the BMSs are trash, and more than likely the cells are permanently damaged.


I had been slowly rising the voltage of the power supply. I came home today and went to raise the voltage up another 0.05 volts to 14.15. Well, before I raised the voltage up, the amp output was showing 0.005 amps which is considerably lower than the 0.015 amps it has been at. So, I checked the cell voltage and found a cell on one battery at 3.78 volts!! I didn’t even bother checking the other ones after that. I’m done with this setup. I’m going to hang on to it all till I can get replacement batteries. After that I’ll probably scrap the cells that have been charging at too high of a voltage, and get a different BMS.


I just can’t rely on a BMS that doesn’t balance the way it should. Maybe this was just a bad batch of them because they do have a good reputation.
Click to expand...


Forgive me for not reading 8 pages and not using the search function that @jorby is likely to point out again.... but what sort of meter are you using to check the cell voltage? or are you depending on the BMS bluetooth out to see that?
 
91cavgt said:
Well, now I’m pretty convinced that the BMSs are trash, and more than likely the cells are permanently damaged.


I had been slowly rising the voltage of the power supply. I came home today and went to raise the voltage up another 0.05 volts to 14.15. Well, before I raised the voltage up, the amp output was showing 0.005 amps which is considerably lower than the 0.015 amps it has been at. So, I checked the cell voltage and found a cell on one battery at 3.78 volts!! I didn’t even bother checking the other ones after that. I’m done with this setup. I’m going to hang on to it all till I can get replacement batteries. After that I’ll probably scrap the cells that have been charging at too high of a voltage, and get a different BMS.


I just can’t rely on a BMS that doesn’t balance the way it should. Maybe this was just a bad batch of them because they do have a good reputation.
Click to expand...
Well I told you quite a ways back before you blew money on a power supply that your non-adjustable BMS were the problem.
Gave you a cheap fix but now you feel the cells are trash it's no matter.

Edit:
The BMS aren't junk it's just you can't adjust them to work properly with those cell packs your running.
 
Drunkin Solar said:
Well I told you quite a ways back before you blew money on a power supply that your non-adjustable BMS were the problem.
Gave you a cheap fix but now you feel the cells are trash it's no matter.

Edit:
The BMS aren't junk it's just you can't adjust them to work properly with those cell packs your running.
Click to expand...
Least he has a variable power supply that he can use for his next adventure.

The other posts I’ve seen on his BMS says it came in some off the shelf 200ah batteries. I wonder how those are doing now.
 
robbob2112 said:
Forgive me for not reading 8 pages and not using the search function that @jorby is likely to point out again.... but what sort of meter are you using to check the cell voltage? or are you depending on the BMS bluetooth out to see that?
Click to expand...

Fluke. These BMSs are around 3-4 years old and do not have any kind of Bluetooth feature.
 
Drunkin Solar said:
Well I told you quite a ways back before you blew money on a power supply that your non-adjustable BMS were the problem.
Gave you a cheap fix but now you feel the cells are trash it's no matter.

Edit:
The BMS aren't junk it's just you can't adjust them to work properly with those cell packs your running.
Click to expand...

I’ve got other projects in the pipeline that require the use of an adjustable power supply so it was easy to justify the expense.


This whole thing has been a $750 learning experience. A tough pill to swallow, but one that I will remember better having learned the hard way.
 
If you disconnect the cells from each other and the BMS it may be possible to see if any of them are actually bad or if they are just abused and a proper BMS would make them happy....

Or buy a proper BMS and swap it out and to see if there is anything that it needs other than that....
 
91cavgt said:
I had been slowly rising the voltage of the power supply. I came home today and went to raise the voltage up another 0.05 volts to 14.15.
Click to expand...

Are you disconnecting the power supply from the battery when you make the change? It's commonly recommended here on the forum that you should not be changing the power supply settings while connected to the battery.

When I charge in steps I follow this sequence:
Turn off the power supply
Disconnect the power supply
Turn on the power supply
Change the voltage setting
Turn off the power supply
Connect the power supply to the battery
Turn on the power supply
 
robbob2112 said:
perhaps pointing out an obvious feature that everyone is aware of and knows how to use isn't being a smartass, or being sensitive... I've attached a report for reference and if you don't stop I will be forced to fill it out and turn it in on you
Click to expand...
Please don't do that. I promise to behave without such extreme measures! 😇
 
Well, as an update, I was able to get a couple of NewtiPower 280 amp/hr lithium batteries to replace this home built battery. I got them for $334 each, then a week later they went up to $539 each. I haven’t done anything with the home built one yet, but I’ve got a couple of ideas on what to do with it.
 
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