nitecore new i4 only charging to 4.05-4.17v

J

jaredes291

New member
Joined
Apr 4, 2019
Messages
6
Hi so I am verynew to cell harvesting and battery pack making so if I am doing anything wrong please let me know.

So I got 11 old laptop batteriesfrom the local recyclingplace and tookthem apart getting around 68 cells (18650) and after testing(Using this thread:How to recover 18650 Cells safely and reliably (I can't post links yet) and only keeping cells that were above 1.75v)
I got 58 cells so then I went on Amazonand searchedfor a 18650 cell charger and the new i4 was the most recommendedone so I got it and started charging the first 6 cells charged to 4.20v just fine but then everycell after that would only charge to around 4.05-4.17v.
so I guess my questionis do I have a bad charger or do I just have bad cells?

if I got the wrong charger what is a good charger? and if I have bad cells is this the normal signs of bad cells so I can identifythem in the future?

Thanks in advance --Jaredes291
 
First off, welcome to the forum

Secondly, I would say your charger is just fine. Might need to be adjusted slightly, though. Unless, you got a knock off of a knock off.

How fast after pulling them out of the charger do they drop to 4.05-4.17 range? If it takes a few days, that's fine. Except for the ones that drop below 4.1V. Normally dropping to around 4.17 or 4.15V is fine if after a few hours. This is normal of LiCo's

Lastly, don't worry about tossing any cells below 1.75V. Just because a cell is low, doesn't mean it's bad. Several experienced members here have recovered 1000's of cells that were below 1.75V and have successfully integrated them into a powerwall application without an issue.

The ones you watch out for are the ones that discharge quickly (like the 4.05V within a few hours), or ones that get hot once they reach around 4.18V (and hot is usually =>50C, 122F)
 
thanks so as soon as the charger says they are done I pull them out and test them and get the reading of 4.15(the latest batch) so would that be normal?
 
Hmm, that is a little soon.

Ok, while they are charging, put your meter on the ends and see what the voltages are. It's possible the charger isn't pushing them all the way up. It might "think" they are 4.2 when they are really 4.15 or so.
 
so I just tested them while charging and the voltages are: 4.16 4.22 4.06 and 4.10v
 
Is that when the charger "says" they are at 4.2V, or almost done? What does the charger display as those voltages? That's the info we really need. Because if there's a discrepancy in the actual voltage and what the charger reads, it needs to be calibrated (if it can be)
 
so the charger doesn't have a voltage readout it just has 3 dots for 100%, 80%, 30%. I might just return it to Amazon and get a better charger
 
Ahhhh, yeah. w/o knowing what the charger is seeing, you have no easy way of knowing what you would need to calibrate. Try a few cells and see if they are all stopping at the same level for each bank. Then you'd at least know a pattern to it.
 
Just check with a cell that is known to be good. Leave one sit for a week or so, and check it for self discharge. It would not surprise me if it is the cells themselves.
 
well, I am gonna let two of the cells at 4.2 and two of the other cells sit for a week and see what happens. in the meantime what's a better charger I can buy. I also need a discharger/tester
 
Opus and LiitoKala are two that a lot of members use. Both can charge, discharge, test. The opus can even be set for storage voltage, which is 3.7V (i think that's value it has) by flipping a switch inside on the pcb.
 
jaredes291 said:
well, I am gonna let two of the cells at 4.2 and two of the other cells sit for a week and see what happens. in the meantime what's a better charger I can buy. I also need a discharger/tester
Click to expand...

If you are on a budget check out the Opus BT C3100 or the LiitoKalaLii-500. The best of the best appears to be the SkyRC MC3000. If you can afford it, you won't regret it.
 
I bought a SkyRC and I spent the weekend learning to use it while harvesting my first pack (more on that later). I got to say it is a sweet piece of equipment. Expect to pay about 100US depending on where you are.

I won't spend that kind of money on future chargers, because I only really need one good reference tester. I figured, if I'm going to get in to this hobby seriously, I need a good baseline tester, and charger, and if not I still need a good charger, because I have a number of these batteries, for flashlights and other equipment. Most of the mid level chargers, are more than adequate for general charging and testing, but it's nice to be able to see the graphs, and have something to check the calibration of the other chargers.
 
jaredes291 said:
Thanks, I will be picking up one of those soon :)
Click to expand...

If you want to go really cheap there is also the ZB2L3 capacity tester. Many people use them in combination with a TP4056 for charging. It is worth mentioning too that if you have a number of ZB2L3 you can hook them up in parallel to test your finished packs.

It is worth mentioning too. Check your batteries for self discharge first. No point in capacity testing cells that are garbage.
 
You must log in or register to reply here.
Back
Top