Has anyone posted somewhere ideal charging currents for different sized lithium ion batteries?

Batteries and Chargers Rechargeable Batteries
1

I’m sure there is a chart or something out there showing the ideal / optimal charging currents for lithium ion batteries, but I sure as hell can’t find it!!!
I know for really small batteries (10440 and smaller) that a 250ma charge should be the max they get, but then on the other hand you have 18650’s that can handle 1000ma charging, and even 26650’s could handle 2000ma (though probably not ideal.)

The reason for this is as I delve deeper and deeper into this hobby I find myself using more and more different types of batteries.
A good example of this is a custom C8 I just bought off a member here that has an XHP70 emitter in it and requires 2x 18350. I’ve never owned this type of battery before so I’m unsure what charge current is good for it and what is too much.

Currently my only charging option is a Nitecore D4, meaning I only have the option of 300ma, 375ma or 750ma. Being the safer (and slower) option I have just been charging them at 300ma, but can they handle more?

Is there a chart somewhere out there I’ve been overlooking for years or am I overthinking this too much? I use only the best batteries and want to treat them with the utmost respect and try to prolong their life where ever possible.

Thanks and sorry if this is a dumb question.

2

It is not possible to make a general list of ideal charging currents. You can do a list of fairly safe charging currents, this is what I do in my charger reviews.

Some will probably post that 1C is a good charging current, other that 0.7C is, but that is not correct for all cells, the Panasonic NCR18650A is rated for 0.3C. Some high current cells are rated for 2C quick charging.

Using too high current is seldom a big risk, but it will reduce the lifetime of the battery.

3

As HKJ pointed out there's no definite list of that because what charge current is good for a battery is a bit a matter of opinion, do you want the promised 1000th charge cycle out of it until the battery dies 25 years from now, or is 200 cycles acceptable while using a higher charge current all the time? And a longterm testing of the actual ideal charge current for each battery is not doable.

This is what I use, some of the batteries are not overly pampered others could be charged faster, but it is limited by what my chargers can provide (Nitecore i4 and OpusBC3100), i.e. my BC3100 has a somewhat cumbersome sequence to set current, so mostly I charge at whatever current a slot is at. It is essentially what HKJ suggested.

Li-ion

10800:60mA, 10440:350mA, 16340:350mA, 14500:350mA, 18650:1A

IMR and other high drain chemistries:

10440:350mA, 14500:500mA, 16340:500mA, 18350:500mA, 18650:2A, 26650:2A

4

Thanks for the comments and advice guys. It’s good knowing that the worst that will happen is fewer recharge cycles and nothing worse.

I don’t know why but I thought if you put too much charge current into a small battery it could vent from the heat generated or something. Glad I was wrong!

So basically, the slower the charge is for a battery, the longer it will last? Of course there are other factors involved, but slow charging will certainly eliminate one of the things that affects battery longevity.

5

As long as you are sensible that is the worst.

Some things not to do:

  • Charge with too high voltage.
  • Continue charging if the cells gets very hot.
  • Continue to charge the cell way past where it was supposed to be full.
  • Charge with way to high current.
6

Unless you know your battery allows higher, just charge at 0.3 C. Label batteries that allow more.

Everyone wants batteries with the highest capacity / best performance they can get. Charge at higher rates than recommended and you will degrade your nice cells. So what was the point of buying good cells?