Ultra Fire WF 188

[louis]

I have started using the mentioned charger & have gotten into a situation.
The batteries I use are generic IMR14500's which charged up to 4.18 on the initial charge using this charger, but after 2 cycles they only charge to 4.05 max.
Is it the battery or the charger?
The charger shows 4.785v when not charging & I can remove, meter & replace & they will charge some more.
Never have they charged to 4.2v but only 4.18v.
Comments please??

louis

 

[Rocketman]

If you trust your meter and the open circuit voltage on the charger is 4.785V, then I would consider the charger dangerous. It MIGHT try and charge a cell that high.

 

[WillyB]

Never have they charged to 4.2v but only 4.18v.

Well assuming that 4.18V is an accurate figure and the charger hit it every time, that's a nice voltage to charge your cells to (at least for Li-Ions) and according to Battery University should extend it's service life.

But things can be quite complicated.

Your charger is not high on this well respected man's list.

650mA setting , the charger seems to terminate all over the place , 4.13v 4.14v 4.15v 4.16v 4.17v 4.18v 4.19v 4.21v 4.22v , in fact it seems to terminate everywhere but 4.2v

One battery has been through 3 charge cycles in this charger , it terminated @ 4.14v 4.17v and 4.22v , its almost like termination voltage is a lottery .

Ultrafire WF-188 TEST !

FWIW this charger gets high marks from the flashlight fanatics, only one channel though.

4Sevens 26650 Battery Charger - 4sevens-store

 

[Rocketman]

and if the charger ever trickle charged a cell left in it to 4.7 volts, I would not want to be around
The open circuit (10meg from the cheap meters) is never over 4.23 volts on any of the chargers I use.


4.785 volts is dangerous, I don't care where a charger is on someone's list.

This isn't "Battery University" stuff,

it's "Battery Hospital" stuff.