It arrived last week. I have only charged batteries a few times but I have noticed that both channels don't shut off at the same charge voltage.
One channel stops at 4.19 volts but the other battery came off at 4.24 volts. I thought it was just a fluke the first time but today I charged two Callie Kustoms 3100s and it was the same thing. 4.19 and 4.24.
Is this a problem or no big thing?
Most charger are 4.2 +/- 0.05, this is normal.
Depends on the battery as well.
I have had the same experience with mine. Left bay always finishes first. Seems to always charge both within the .05v tolerance.
Does 4.24 volts harm my battery or is it dangerous to charge them up that high? My other charger is a cheap Chinese charger but they always come off that charger at 4.18 ever time.
The variation is good, chargers that only ever charge cells to a set voltage are simple CC chargers with a cut-off voltage. As I understand it, a charger with the proper CC/CV algorithm switches to the CV stage near the end of the charge and terminates when the current to the cell (determined in this phase by the cells remaining capacity not a set current) drops below a set amount (normally around 100ma).
This means that a good charger should charge older or lower quality (not necessarily lower capacity overall) cells to lower termination voltages than newer, fresher cells.
However, a termination voltage of 4.24v on any li-ion cell could be a problem, and while there will naturally be variation, maybe there is something wrong with that charging bay. It shouldn't cause a serious risk of explosion or fire etc, but may wear down the cells more quickly than a charger that terminates below the 4.2v recommended limit every time.
What are you measuring your voltages with? I find it's been best for me to use at least 2 DMM's to compare, I am very OCD so I actually use 3. A craftsman, extech, and a fluke.
It's called a CEN-TECH and I have two of them. They have both registered the same voltage.
Which cen tech model? Similar to the free red ones at harbor freight? I have a few of those and they have been off up to half a volt for me before.
Are you measuring the voltage while the batteries are connected to the charger or disconnected?
It says P35761. I test when they are not in the charger.
Did you use 500mA or 1000mA charging current? Test both.
Try also inverting same batteries, i.e. battery from bay #1 to bay #2 next time and vice versa. See what happens.
Also, you could test to charge only half-empty battery.
If in all cases it overcharges, then it is different than mine ;)
My Xtar seems to do a bit higher Voltage on cells, which seem to have less internal resistance (give more Amperes out).
I ran down a couple Redilast 2900 batteries to 3.83 volts and placed them in the Xtar again. It was on the 1000mA setting. They both shut off at about the same time and the one on the left was at 4.19 and the right one was 4.25.
I will try again tomorrow at 500mA and see what happens.