what volt do i charge my 26650 cell?

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blueb8llz
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what volt do i charge my 26650 cell?

hello, this maybe a silly and simple question but i just received my king kong inr 26650’s 4000mah 3.7v batteries, and before i charge them, there is a selector switch on my trustfire tr 006 charger that reads 4.2v or 3.0v. which mode do i need to put it at to charge my batteries?

borstar_micke
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4.2v

blueb8llz
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thanks

borstar_micke
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It´s actually a little funny that you charge 3.7v li-ions to 4.2v, and 3.0v rechargeables is charged to 3.6v if I remember correctly.

Battery University is a really great site with a lot of useful information for flashoholics. Smile

blueb8llz
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ill take a look into that college. thanks

scaru
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borstar_micke wrote:
It´s actually a little funny that you charge 3.7v li-ions to 4.2v, and 3.0v rechargeables is charged to 3.6v if I remember correctly. "Battery University":http://batteryuniversity.com/ is a really great site with a lot of useful information for flashoholics. :)

The reason is that 3.7 volt li-ions are half discharged at 3.7 volts and 3.0 volt ones are half discharged at 3.0. Atleast that is what I think it is. 

texaspyro
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scaru wrote:
The reason is that 3.7 volt li-ions are half discharged at 3.7 volts and 3.0 volt ones are half discharged at 3.0. Atleast that is what I think it is.

No, a 3.6V LiFePO4 cell is pretty much depleted at 3.0V (maybe 5% capacity left). You really can’t tell their remaining capacity from the voltage from 3.3 to 3.1V since the discharge curve is so flat. 80% of the capacity curve sits around 3.2V

scaru
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texaspyro wrote:
scaru wrote:
The reason is that 3.7 volt li-ions are half discharged at 3.7 volts and 3.0 volt ones are half discharged at 3.0. Atleast that is what I think it is.
No, a 3.6V LiFePO4 cell is pretty much depleted at 3.0V (maybe 5% capacity left). You really can't tell their remaining capacity from the voltage from 3.3 to 3.1V since the discharge curve is so flat. 80% of the capacity curve sits around 3.2V

Oh, ok. Then why are the lifepo4 cells marked 3 volts? Just so people will buy them as a direct replacement for CR123As? Silly 

edc
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I didn’t even know that switch existed on my tr 006

 

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texaspyro
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scaru wrote:
Then why are the lifepo4 cells marked 3 volts?

You’ll have to ask the people that marked them. Most reputable makers call them either 3.6V or 3.2V cells.

Here is some info on my testing of some A123 2300 mAh M1 cells:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=20698