Time?

[jevans]

How long does it take to charge a 18650?

Whether I use a computer USB, mains USB adaptor or direct mains powered charger, it takes about 4hrs 40mins!

Is this the norm, or is there a safe faster charger?

Jim

[DiscoDes]

What mAh is the battery?

[VapingBad]

A 1 A mains charger would be more like 2 hours depending on the battery, I use two 2 A charges and can charger 4 batteries in under 90 mins, but a lot of batteries can't safely charge that fast.

[thatguy]

It depends on the mah of the cell and the charge rate of the charger.

Divide the mah by the output current of the charger for a rough estimate of time in hours. A little longer than this will be needed due to inefficiency.

An example....2000mah cell charged at 500ma will take 4 hours,and add on 15-30 mins for losses such as heat.

[VapingBad]

It's the final stage of charging the constant voltage stage that adds the time thatguy, newer chargers don't add as much as they used to. that often took a third of the time, but more like 15-20% of the total time. There is a EEBlog video linked in the guide in my footer that explains the stages etc.

[jevans]

So it looks like all my chargers are about 500mA, which according to thatguy should take c. 5hrs.
The 18650s I'm using are Samsung 25R.
Can anyone name a safe 1A or 2A charger as VapingBad ? didn't mention which charger he used.

Jim

[hijack]

The above is the only way to work it out, I have a tablet with a 10,000mAh battery in it and with a 2.1A charger and a decent usb lead it takes about 6 hours to charge up from 15% left which is when it starts to warn me every 5 mins.
Even having a decent usb lead makes a difference as charge is lost due to resistance in the lead. A 28 AWG lead will make a big difference over a cheapy to the time it takes to charge.

[VapingBad]

Jul 17, 2015 6:49:53 GMT jevans said:

So it looks like all my chargers are about 500mA, which according to thatguy should take c. 5hrs.
The 18650s I'm using are Samsung 25R.
Can anyone name a safe 1A or 2A charger as VapingBad ? didn't mention which charger he used.

Jim

I charge my 25Rs at 2 A on Xtar SP2 IIRC KingsOfVapour have then for about £16 delivered ATM.  I only charge batteries at 2 A if therir Fast Charge rate is about 4 A, so be careful with that feature for other batteries.  25Rs take 90 mins for a full charge at 2 A.  All 18650s should be OK to charge at 1 A, this charger does 0.5, 1 & 2, but doesn't do 18350s.

[VapingBad]

This one Jim www.kingzofvapour.com/products/xtar-sp2-dual-bay-fast-charger

[jevans]

Many thanks for the URL VapingBad

Jim

[jevans]

Jul 17, 2015 6:58:17 GMT VapingBad said:

This one Jim www.kingzofvapour.com/products/xtar-sp2-dual-bay-fast-charger

Ordered!

Can I charge a 22P at the 2A rate?

Jim

[VapingBad]

Jul 17, 2015 7:20:47 GMT jevans said:

Jul 17, 2015 6:58:17 GMT VapingBad said:

This one Jim www.kingzofvapour.com/products/xtar-sp2-dual-bay-fast-charger

Ordered!

Can I charge a 22P at the 2A rate?

Jim

Samsaung ICR18650-22P

The spec say Rapid Charge Current is 2.15 A, so they are safe to do so, but I would charge those at 1 A as going close to the charge limit can shorten their life.

[jevans]

VapingBad
Ta!

Jim