Xtar SP1 undercharging

[mihail]

I got some issues with a JetBeam charger and sent it back. Now I'm looking for a Li-ion charger (max 2 bays). I was thinking that Xtar SP1 would do ... A friend of mine has one but he keeps telling me that it undercharges all his Li-ion cells. When set to 3,6V the max voltage applied to cell is 4.14V. At rest the cells drop to 4.12 or lower (depending on the cell).
What do you think? Is it 4.14V too low? I know that is good for these cells not to be charged at 4.2 (to max cycles), but, again, isn't 4.14V too low?

 

[Norm]

*XTAR WP2 II ...not impressed.

That is just about the perfect voltage.



No, charging voltage is 4.2 +/- 0.05 volt, resting voltage will be lower. How much lower depends on a lot of factors, including age of battery, termination current and time since charging.

A charge curve looks like this (This is from one of my battery tests):

Norm

 

[mihail]

I have just finished reading the thread in your previous link (about "overcharging a cell at less than max voltage"). Very interesting! I was wondering where is HKJ's post in that thread... Now I see you put the right link. I'll keep on reading!
Thanks!

 

[Norm]

Just a little forum hint, you can always go to the correct thread by clicking the blue arrows next to HKJs user name in the quoted post

Norm

 

[mihail]

After I finished reading the post in your link I ordered a Xtar SP1. It has arrived already and i have used it to charge 14500 and 18650 cells. I measured the voltage it applies to cells at CV stage and it is 4.19V. At rest, the cells have between 4.15-4.17V. I am very pleased with it!
Thanks!