Battery Chargers

[Vapor Pete]

I have three different types of chargers for the kr808-D's. Each one charges for different amounts of time. Wall plug with screw in charger takes about 2 hrs to charge a batt... wall plug with USB adapter takes about 4-6 hrs, and the USB plugged into the computer takes all freakin day. Anyone know why this is? I love the first one because the batt is ready in so short a time, but I often wonder if its not giving a full charge?
Anyone?

-VP

 

[YKruss]

Pete,

Simply said each chargers has different charge current "ma" (milliamper).

Charger with 100ma current needs 3.2 hours to fully charge your 320 mah LiOn battery.
But charger with 300 ma current only needs a little bit over one hour to fully charge the same battery.

(I might be wrong but not much)

 

[lorikay13]

So where exactly can you even get a charger with a 300 ma rating? I would love to find one for my V4L XL's (380 maH).

 

[john doe]

they can't make the chargers too fast or you run the risk of exploding batteries. think of the battery as a balloon and the charger as a water hose. if you use a hose on a low pressure main then it may take a while to fill. put it on the tap outside the house and it's pretty quick. put it on a fire hydrant and the balloon goes pop as soon as you turn on the water.

 

[YKruss]

I was trying to give a simplified answer but the issue of course is more complicated

The charge cannot be terminated on a voltage. The capacity reached at 4.2 Volts is only 40 to 70% of full capacity unless charged very slowly. For this reason you need to continue to charge until the current drops, and to terminate on the low current.

It all depends on smart electronic guts of a charger and at what rate it is chatging the battery - below, at or above 1C (battery capacity).

 

[WillyB]

So where exactly can you even get a charger with a 300 ma rating? I would love to find one for my V4L XL's (380 maH).

It ain't gonna happen. None of the e-cig chargers follow the correct Li-Ion charging specs, they only pump out 150mA tops ( 300mA constant is probably too much for those batts anyway). The usual TrustFire/UltraFire chargers you see for larger batteries also do not properly follow spec. The problem mostly being that they continue to 'trickle' charge, never shutting off completely and will charge the Li-Ions past 4.2V. According to Battery University overcharging a 3.7V Li-Ion to 4.3V will shorten it's longevity (amount of charge cycles) by about 25%. The flashlight fanatics have various charger mods to make sure the battery comes out of the charger at about 4.19V.

This graph will illustrate YKruss' comment on how charging should be done.

A good Li-on charger is relatively expensive.

Buy Pila IBC™ 4-stage Charger, AC Adapter, Carrying Case | Pila BC01-AC01

 

[h8isgr8]

A good Li-on charger is relatively expensive.

That's not true at all.

I've built chargers for my ecig batteries out of Maxim's MAX1555 charger IC. The only cost involved was two ceramic capacitors, solder, wire, and my time.

I get the full ~280mA initial charge current, and the fully charged voltage always measures exactly 4.204V on my meter.

Oh, and I haven't had any batteries turn into nuclear bombs charging at 280mA either. Not even with ~120mAh super mini batteries.

 

[lorikay13]

okay...so from a practical point of view of an electrical idiot, (me)...would taking your batteries out of the charger as some as the charger indicates it is done help extend the life of the battery?

 

[PaganPaul]

My batts are 306, 306a and 510, so this may not apply to you, but see my signature picture below...

 

[BillTech]

cool charger

 

[BillTech]

dupe sorry