XTAR VP1: which charging current to use?

[Inannalu]

The XTAR VP1 permits the user to select from one of three charging current options when charging: 0.25A, 0.50A, and 1.00A.

The paperwork that came with the unit says that 0.25A is appropriate for 10440 to 18700 batteries, 0.50A is appropriate for 17670 to 18700 batteries, and 1.00A is appropriate for only 18650 and 18700 batteries.

Thus far, I have charged 14500 protected, 18350 IMR, and 18650 IMR, each with the 0.25A setting (being brave enough to only twice charge the 18650 IMR with the 0.50A setting).

What is optimal? Do I risk anything, should I always charge the 18650 IMR at 0.50A or 1.00A?

 

[WattWick]

Ideally you shouldn't be charging above 1C. Which I guess takes a little explaining.

1C is a charge / discharge rate. To figure what this would be for your batteries, convert the mAh rating of your batteries to from milli-Amp-hours to amp-hours. Do this by dividing by 1000. I.e a 2000 mAh battery would have a 1C rating of 2 amps. A 700 mAh battery, 0.7 amps. And so on.

I can't think of any 18650 batteries with lower capacity than 1000 mah. So, you should be perfectly fine charging them at 1 amp. It's for the smaller batteries you would use lower amperages.

Think I just confused myself a little. It's a simple concept, but can be hard to explain in a simple way. Hope you got it

 

[Inannalu]

So 750mAh, 800mAh, and 900mAh would each be okay charged at 0.50A, irrespective of size or type (protected or IMR)?

 

[WattWick]

Yep should be fine. They can probably be charged at over 1C as well, but I think it's generally accepted as "better" to not exceed this.

 

[djslik]

To prolong the life of the battery 0.7C is thought to be a safe number and the maximum is 1C.

How to Prolong Lithium-based Batteries - Battery University

 

[Rule62]

It's generally accepted that the slower you charge, the longer your batteries will last. I usually charge my 18350s at .25A. My 18500s and 18650s at .5A. However, if I'm in a hurry, I'll charge the 18500s and 18650s at 1.0A. I never charge 18350s over .5A.

 

[NoBS]

It's generally accepted that the slower you charge, the longer your batteries will last. I usually charge my 18350s at .25A. My 18500s and 18650s at .5A. However, if I'm in a hurry, I'll charge the 18500s and 18650s at 1.0A. I never charge 18350s over .5A.

Right on the money! Basically, it's the heat that kills 'em. Faster charge is just a means to a faster heat up of the chemicals.
Summer heat + in a car = fast death of battery!
I always have a small fan at my charging stations, especially for the extended battery of my cell phone.
Hmm, which reminds me, my 3 year old smarter than me phone is in need of an up-grade...