# Charging a 18650 ?



## ynotfatboy (Aug 23, 2012)

I have a XTAR SP2 charger and a xtar 18650 3100mAh battery. I can charge the battery at 0.5A,1A or 2A. What Is the recommended charge rate? Is it easier on the battery to charge at a low rate 0.5 rather than 1A? Can I charge at 2A if I'm in a hurry?


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## HKJ (Aug 23, 2012)

ynotfatboy said:


> I have a XTAR SP2 charger and a xtar 18650 3100mAh battery. I can charge the battery at 0.5A,1A or 2A. What Is the recommended charge rate? Is it easier on the battery to charge at a low rate 0.5 rather than 1A? Can I charge at 2A if I'm in a hurry?



Recommended charge rate is 825mA, I do always use 1A. Higher charge rate will increase the wear on the battery and doubling the charge current will not halve the charge time.
In my review of the SP2 you can see curves for charging a 3100mAh battery with 0.5, 1 and 2A, the charge time is under the curve.


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## ynotfatboy (Aug 23, 2012)

HKJ said:


> Recommended charge rate is 825mA, I do always use 1A. Higher charge rate will increase the wear on the battery and doubling the charge current will not halve the charge time.
> In my review of the SP2 you can see curves for charging a 3100mAh battery with 0.5, 1 and 2A, the charge time is under the curve.



Thanks HJK I purchase this charger on yours and Shadowww recommendation. How did you come up with a charge rate of 825ma incase i get a different mAh battery. Will a lower charge rate lessen the wear on the battery?


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## Shadowww (Aug 23, 2012)

ynotfatboy said:


> Thanks HJK I purchase this charger on yours and Shadowww recommendation. How did you come up with a charge rate of 825ma incase i get a different mAh battery. Will a lower charge rate lessen the wear on the battery?


825mA is recommended by Panasonic in NCR18650A's datasheet: http://industrial.panasonic.com/www-data/pdf2/ACA4000/ACA4000CE254.pdf (actually it says 855mA).
Lower charge rate (at least 0.5A vs 1A for a 3100mAh cell) won't lessen the wear, in fact it might increase wear due to 0.5A charge terminating at lower CV cut-off current than 1A charge.


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## LightCrazy (Aug 25, 2012)

Glad I read this. I am charging my Xtar 18650 3100mAh battery on my Xtar WP2 II charger right now, and have it set for the 500mA setting. It has been on just over three hours now. Battery and charger are cool. My thinking was that the 500mAh charge would create less heat and bring the battery up to charge more evenly?


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## Shadowww (Aug 25, 2012)

LightCrazy said:


> Glad I read this. I am charging my Xtar 18650 3100mAh battery on my Xtar WP2 II charger right now, and have it set for the 500mA setting. It has been on just over three hours now. Battery and charger are cool. My thinking was that the 500mAh charge would create less heat and bring the battery up to charge more evenly?



Uh.. NCR18650A's (eg Xtar 3100mAh's) don't get warm enough to worry about it even at 3A, which is way over-spec. You really should charge them at 1A instead of 0.5A.


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## LightCrazy (Aug 25, 2012)

Ok here's how it went. The new3100mAh battery was at 4.13 V new. I ran it down intermittently with a halogen flashlight bulb until the battery itself- no load, was at 3.595volts. I put the battery in the Xtar charger and set it for 500ma. At 3:45 hours I read this post, and changed the charger to 1 amp. At 5:12 hours I had to leave, charge light was still red. I took the battery off the charger and it measured 4.15 volts right off the charger. When I returned a few hours later, the battery had settled at 4.13 volts, right where it started.
now I can't wait to try it in a light.


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## LightCrazy (Aug 26, 2012)

Any input on how my first charge session went? From now on I will charge at the 1A setting.


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