14500 Batteries

[Kemosabe]

I've never charged these batteries before. Its two 900 mah TrustFire 14500 3.7V Li-ion batteries. My charger is a dual 14500. How long should I charge them for?

...there is a light on the charger marked 'charge', but im not sure if itll change color when charged or not. i dont want to overcharge.

 

[cskent]

Most chargers, even cheap ones, will not overcharge. They quit charging right around 4.2v. The light will tell you when they are fully charged, then you can take them out and unplug your charger.

 

[st0nedpenguin]

I was under the impression most cheap chargers would trickle charge.

 

[Kemosabe]

i was told in other words a separate thread that a 600mah output charger would put 300mah per hour into each battery if i charged both batts at once. so using that formula, my 900mah batts should take 3 hours. would that be true?

later i noticed the charger's input max is 150mah. does that play a role in the formula?

 

[cskent]

Yes, that plays a major role in it. That's a really low ouput charger. You might want to consider upgrading, especially if you ever end up getting an 18650 mod. It would literally take all day to charge those large capacity batteries at 150 mah.

 

[martinc]

The blue little buggers?

Nice batts,''green batteries'' overcharge and severe discharge protected,last a long time,awesomeness.

 

[Kemosabe]

no these are the red and black ones with the flame logo near the negative post

these:

 

[Kemosabe]

lol i didnt realize that was you i was talking to in the other thread cskent.

i like your original calculation better. can we just use that? lol

once these batts die im gonna slap em on the charger and figure this out once and for all. im gonna pray for the light to go off, or change color at the 3 hour mark... but im not going to be surprised if nothing happens for several hours later.

i just would like some sort of verifacation from the charger that theyre done. in your experience, do these type of chargers typically have an indication of a full charge?

 

[cskent]

The batteries themselves won't give you any indication that they're done charging. The light on the charger should change color though. Another way to check is to use a multimeter on the batteries before putting them on to check voltage. It should read about 3.2v. Check them periodically and you should see that they're increasing in voltage. When they finally reach around 4.2v the light on the charger should indicate that charging is complete. If they reach around 4.3v then they're overcharging.

 

[WillyB]

The batteries themselves won't give you any indication that they're done charging. The light on the charger should change color though. Another way to check is to use a multimeter on the batteries before putting them on to check voltage. It should read about 3.2v. Check them periodically and you should see that they're increasing in voltage. When they finally reach around 4.2v the light on the charger should indicate that charging is complete. If they reach around 4.3v then they're overcharging.

That's not exactly correct. Better chargers use the CC/CV charging algorithm. Charge termination is determined by current, not voltage.

 

[Kemosabe]

update: the batts took 4 hours to charge from death.

and the light on my charger does indeed change color. prettay sweet.

 

[Kemosabe]

what an upgrade this mod was BTW! i am getting 24 hours of use ...or a day and a half if i sleep