I’d rather err on the high side and end up with 4.2V after the battery settles than end up with 4.16-4.18V. I went through a couple chargers (xtar&nitecore) before I found a good one (liitokala) that would charge a cell the way I want it to.
Thank’s for this explanation. It is very much needed, I’m sure, judged from many posts from newbies (and also some old-timers).
I have a kind suggestion that you in the sentence:
“For the charger to be within specifications the voltage must be between 4.15 volt and 4.25 volt.”
change “voltage” to “charge voltage”, because some will refer to the picture just above (and then we have chaos again).
Thanks HKJ, I’ve been wondering why my hobby charger (Duratrax 235) stops before the battery reads 4.2. It must have a safer/long cell life type termination. I would have thought it could be adjusted but I don’t see a setting for it in the manual.
You probably get about 2% more performance and 10% less battery life that way. Go for it!
I made up those numbers… O:-) but the concept is valid if not the specific amounts.
Thanks for this. Occasionally I will encounter a charger that charges slightly over 4.2, but never more than 4.25. I had wondered if this was a safe voltage. And on a side note… What is the lowest safe discharge level for a lithium ion. I’d thought it was around 2.7 for a lot of them. Is this right?
Your expertise with LiIons is very much appreciated by all of us, so if you do a post on how low a cell should be allowed to go that will meet with an equally warm reception.
Ok so it’s safe, that’s good… But what is an ideal voltage. I test many lights, some of which do not have low voltage protection… And I often wonder what is an ideal voltage… What’s a safe voltage, what’s unsafe? Below 2.7? What is the lowest voltage that is best for the longevity and health of the cell… Or what is a dangerous voltage. There is such scattered and contradictory information out there, so I’d like to know.
But there definitely needs to be an article written on the subject.
Then you aren’t going to be happy since there are many “opinions” on those numbers. IMO, and in my own practice, I try to keep the voltage above 3.0v at all times and generally above 3.2v. There is VERY little capacity under 3.0v and the volts drop precipitously after that making it a slippery slope. There just is not a lot of good reason to push that far unless you are in an emergency situation. Why bother?
Once you go under 2.5 it gets dicey. Below 2.0 you are likely getting into damage area.
You don’t get immediate problems from over discharge, you get problems from charging AFTER over discharge and the damage it may incur.
I have tested a lot of lights and have found most commonly some cutoff point is around 2.6-2.8, which is why I was wondering. I often wonder why it’s usually about this voltage. I understand there isn’t a real consensus, but I wonder why that number is common.
I finally got a charger that charges to 4.2V, i suspect the ML-10X chargers are just made with components with loose tolerances because they finish charging from 4.04-4.11V, battery tested immediately off the charger.
Its interesting to note the voltage drops slightly as soon as removed, i suppose this is not well covered on BLF (add to the li ion thread ), so my 4.20V charger right off the charger must mean its charging to 4.22ish volts. I’m not going to complain, after living with 4.04V for years i’m happy to get a full charge.
I did some tests once with batteries that came of at around 4.2v versus 4.17v (Nitecore I2 and Opus 3100 respectively) and from memory the difference was about 1.8% when I discharged them on my Accucel 6. Wouldn’t be useful or noticeable in real life usage for me.