Li-Ion Charge rates.

[Glock27]

Battery University recommends a charge rate between .3 to .7c.

I mostly charge Panasonic 18650 3100 and 3400 mAh batteries.

Does charging at the higher .7c rate have a large effect on cell life?
If Pila IBC outputs ~600mAh that would only be ~.2c.
I bought an Xtar SP2 which is capable of a 2000 mAh charge rate.
Should I stick to the 1 amp setting or pump the max rate?

B27

 

[Thr3Evo]

From what I hear, it all depends on how much you value those cells. And also the chemistry, and manufacturer (trusted ones) recommendations. If you're within those perimeters I believe you are safe to charge on the higher end of specs(with proper charger).
Now comes the "value" which I mentioned earlier. And I don't mean monetary, although I suppose it is somewhat related.
Think of this cell like an engine in a car, see those red lines on the dash at the end of the RPM gauge? The engine operates at those numbers right? But the question is "for how long"?

Now I have a question to add to the original one:
What about the other extreme. I see most cheapo chargers run around 350mA, which from OP that's below even the recommended .2C of say a laptop rescue cell... Around 2000mA
Will this affect its life time in any way?

 

[Shadowww]

Depends on whether you more value your cells, or your time. I charge my Panasonic 3100mAh batteries at 3A - 5A all the time (2x in parallel, using hobby charger, at rates of 6A and 10A), and so far (30+ cycles) they haven't dipped below 3000mAh.

 

[Glock27]

The low range given (.3c) was set for a reason too I would suppose. Providing a minimum amount of current might be needed to force the electrolyte back into optimum efficiency. Charging at to slow of rate might actually be bad for the life cycles of the cell. They could have easily set the lower range at a lower value but intentionally didn't. The Pila charge rate is well below .3c. The Xtar could do the .7c.

G27

 

[march.brown]

I only ever charge at one amp even with my Panasonic 18650's , using my very cheap (Ebay) charger boards ... I don't have any of the Panasonic 3400mAh cells yet ... If or when I do buy some , I will use two of the charger boards in parallel ... I also only use a one amp charge rate on my AA Eneloops with my C9000.
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