Charging to 4.3v

Joined
Oct 10, 2018
Messages
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Hey team,

I have just purchased some charger units for a bit of an experiment and turns out they use a USB plug in and give a 'full' charge as indicated by a green LED.


image_epviwx.jpg





I then threw them in the opus once charged and they came up with a voltageof 4.3v on each cell!

What are peoples thoughts on that level of voltage? As I understand 4.2 is full and 4.3 is getting dangerous?
 
Scottietheyoung said:
Hey team,
I then threw them in the opus once charged and they came up with a voltageof 4.3v on each cell!

What are peoples thoughts on that level of voltage? As I understand 4.2 is full and 4.3 is getting dangerous?

Most cell manufactures have a4.2 0.05 V spec on their cells. Also some cells actually go as high as 4.35V.
If the cell gets to 4.25 and the Opus decides to round up that would be your answer. Also the OPUS as a voltmeter :huh: Im not sure I would trust it that close.Best would be to check the voltage with a minimum of a 3 decimal place DVM or better yet with a 4. :D


image_tzhsdj.jpg


Wolf
 
Life shortening if done regularly.
Some cells can take 4.3(5), most probably won't like it but not dangerous.
4.1 = full is the target for longer term power wall use, for capacity testing you're trying to follow the manufacturers specs hence 4.2V

+1, find a voltmeter you trust!
 
Take the unit apart and see if there's a switch inside to change from normal cells to HV (high voltage) cells. Maybe it's default setting is HV instead. But, I doubt this is the case. Even the Opus has 2 charge levels, but it's 4.2 and 3.7 (for LiFePO4 cells).
It's also possible you have a bad charger, even if new.
 
I'm in the process of bringing all mine down to 4v top voltage to try make them last as long as possible. but like wolf said, trust neither for a true reading
 
Korishan said:
Take the unit apart and see if there's a switch inside to change from normal cells to HV (high voltage) cells. Maybe it's default setting is HV instead. But, I doubt this is the case. Even the Opus has 2 charge levels, but it's 4.2 and 3.7 (for LiFePO4 cells).
It's also possible you have a bad charger, even if new.

possible but that looks like another cheap and nasty charger i had.
i knew it was crap when i got it for $5 at the flea new in box.
it had no real cc or cv modes and while testing it shorted placing full 5v across that slot.
that could lead to a nasty surprise.
the sliders were so crappy it wasnt even worth re-purposing as a universal holder.
 
Thanks team, they were super cheap and definitely nasty. As I said it was a bit of an experiment for me to see what you could get for that pitiful amount of money. The internals were appalling when I opened it up. Will bin and build charging board.
 
Scottietheyoung said:
Hey team,

I have just purchased some charger units for a bit of an experiment and turns out they use a USB plug in and give a 'full' charge as indicated by a green LED.


image_epviwx.jpg



I then threw them in the opus once charged and they came up with a voltageof 4.3v on each cell!

What are peoples thoughts on that level of voltage? As I understand 4.2 is full and 4.3 is getting dangerous?

I have 6 of them. All of them overcharge to between4.23-4.28 V. I bought a tube of TP4056 with the plan of replacing the ICs in them, but the pinout is different so its not based on that. Been thinking about etching a new PCB for it but I would need to desolder and move the hooks for the springs.


Korishan said:
Take the unit apart and see if there's a switch inside to change from normal cells to HV (high voltage) cells. Maybe it's default setting is HV instead. But, I doubt this is the case. Even the Opus has 2 charge levels, but it's 4.2 and 3.7 (for LiFePO4 cells).
It's also possible you have a bad charger, even if new.

Nope. Unbranded IC/scraped the letters off them. Termination voltage seems internally set by bandgap reference, or in this case badgap reference.
 
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