What is the maximum safe amperage to charge cells at? Is it a C rate or just general rule of thumb?
Interested in pretty much all of them :bigsmile:
10440
16340
14500
18350
16650
18650
26650
Oh and also Ni-Mh(AA/AAA), what voltage/amperage should they be charged at?
i usually charge all my batteries at .5 c, whether it be li-ion, pb or nimh…
You get a more “full charge” and more battery life that way.
So if you got 2000mah batteries, charge at 1 amp (or less if you have time)
With Lithium Ion chemistry, I’ve read over the years that the highest charge rate should be 1C although many recommend a 0.5C rate. (LiPo and LiFePO4 are different.) Personally, I charge mine closer to .5C than 1C.
I have some Sanyo 2600mAh cells that have average internal resistances of 100m ohm. When one is completely drained and I start recharging it at 1.5A, voltage (as displayed on the charger’s screen) increases only a little, maybe by 0.5V (ie, from 3.10V to 3.60V when I start recharging.) The battery pack from my Shadow BL-21 light has three 18650 cells in parallel and a higher internal resistance of about 240m ohms. If I put this pack to recharge at 1.5A, displayed voltage shoots up to 4.1V or higher… In a case like this, I’ll charge this pack at 1000mA or below since the internal resistance is so high. (The charger that comes with the BL-21 charges at 1000mA.)
NiMH are a little different. It is recommended that if you use your NiMH in high drain applications, it’s better to charge them at 1C but, if you use them in lower drain applications, charge them at 0.5C rate. I’d figure that AAA NiMH cells will always be dischaging close to their C rating so 1C charge rate (close to 1000mA) is best. Again, if internal resistance of a NiMH cell is high, when it is being recharged, the displayed voltage shoots up pretty high and here, I’d surly charge at 0.5C or less. I’ve had old cells charged at 1000mA (<.5C rate) that had voltages of 1.75V or higher. Usually, I trust the charger’s auto charge fuction (based on internal resistance I believe) if the cells are old/oldish.
Truthfully, the most trusted NiMH charger I have is an 8 bay thing that charges around 750mA and all my AA and AAA cells goes into it on a regular basis.
I just got back from a new Mexican restaurant… you don’t want to be anywhere near what I’m venting… J)
Thank you for the great information eebowler and aoyue2702!
Too much information. 