I used my VP2 for the first time today. As it was charging at an indicated 4.2v, I touched the battery to see how warm it was. The charger gave the green light and I figured it was just coincidence. Then I charged another battery and when I check to see how warm it was at the 4.2v charging it too gave the green light. However, when it stopped charging the voltage display went to 4.14v and I read the same on my DVM. I inserted the battery into the charger and it charged for nearly another hour. I didn't touch it this time, waiting on the green light. It charged to 4.21v on my DVM. Any thoughts on what's going on?
noob question about XTAR VP2 Charger and NCR18650GA protected batteries
- Thread starter zarko550
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usdiver
Flashlight Enthusiast
Hani's for that
ChrisGarrett
Flashlight Enthusiast
By moving the battery/cell, or turning it slightly, you break up any 'contact resistance' and this can be enough to trigger the green lights.
I rotate my stuff, while it's charging, regularly and it's normal to move one and then watch the green light come on.
Chris
I rotate my stuff, while it's charging, regularly and it's normal to move one and then watch the green light come on.
Chris
ChrisGarrett
Flashlight Enthusiast
You want to rotate them within the cradle.
Like Martha Stewart is fond of saying:
"And that's a good thing!"
Chris
ChrisGarrett
Flashlight Enthusiast
As I understand it, resistance builds up and slightly obstructs current flow. This causes the charger to balk, or stall a little bit, on termination.
By turning them, jiggling them, removing one and jarring the other, that resistance is removed and things proceed on their merry way to full termination.
It's usually when a cell is right at the end of charging, so you won't put in a depleted Eneloop, or 18650 and start turning it, only to have the charge terminated after only 5 minutes.
Chris
Last edited:
More great info to learn
I was wondering about the LG INR18650-MJ1. Are those also supposed to be charged with the 3.6V setting on the VP2?
Every time I think I have this figured out it seems like another question comes along. After resting overnight, two new batteries I charged yesterday on my VP2 were indicating 4.17v and 4.18v today. Does that sound right or should they be 4.2v? I'm thinking I read that this is OK and more healthy for the longevity of the batteries.
Thanks again.
Thanks again.
ven
Flashaholic
Sounds fine to me, just make sure they dont drop much over a week. I find most of my cells settle to around 4.18 ish and tend to stay there.
ChrisGarrett
Flashlight Enthusiast
More great info to learn
I was wondering about the LG INR18650-MJ1. Are those also supposed to be charged with the 3.6V setting on the VP2?
'Multi-quote', better than a 'multi-pass'.
Yes, all 3.6v/3.7v cells which charge up to ~4.20v should use the 3.6v setting on the VP2. The 3.8v setting is meant for the 4.35v cells like the Sanyo 16650 2500mAh cells, or my LG D1/E1 18650s.
There are others, but all of the cool kids were running them a few years back and Xtar built in that algorithm for 'us'.
The 3.2v setting is for 'storage voltages' on 4.20v/4.35v cells, or when using LiFePO4 3.2v cells. The off the charger voltage on this setting is about 3.6v-3.65v, which is a good 40-50% SOC level to get your li-ions to, before putting them in the fridge for storage.
Remember, the algorithms terminate the charge at 4.20v (+/- .05v), but the batteries once removed will settle. How much they settle depends on the condition of your li-ion cells and NiMH batteries. If you've got 300 cycles on an 18650, you might get a settling to 4.16v, or less. I have some 5 year old AW ICR 16340s and they come off various chargers at ~4.17v, if I'm lucky, then settle down to a 4.10v-4.11v in less than a day.
They're old, but still have some usable capacity left (400mAh @ 500mA), so I keep them around.
Still, some chargers undercharge and some slightly overcharge. Undercharging is better for the cells long term. I recently bought four Liitokala USB chargers: two 100 single bays and two 202 double bays. They're functionally identically but for the extra bays.
Both of the dual bay 202s undercharge either 4.20v cells, or my 4.35v cells, more than just accounting for loses (in my mind) due to age. However, both of the single bay 100s overcharge my various cells, to the tune that on my RatShack 22-805, I see 4.22v-4.23v regularly.
I'm somewhat new to this stuff, but I can count the times on one hand, where I've seen a voltage greater than 4.20v.4.21v after a green light. Hell...I even have a NiteCore i4 v.2 charger that notoriously overcharges and it works fine, so go figure?
Chris
ven
Flashaholic
I want to be one of the cool kids Chris, as i have a few 4.35v cells in use.................do i qualify
As Chris states with the +0.05 and -0.05v spec, that means simple 4.15v to 4.25v is actually in most manufacturers specs for their chargers...............
As Chris states with the +0.05 and -0.05v spec, that means simple 4.15v to 4.25v is actually in most manufacturers specs for their chargers...............
ChrisGarrett
Flashlight Enthusiast
I want to be one of the cool kids Chris, as i have a few 4.35v cells in use.................do i qualify
As Chris states with the +0.05 and -0.05v spec, that means simple 4.15v to 4.25v is actually in most manufacturers specs for their chargers...............
Hi Ven! I don't know if I'd buy them again, but I'd buy the Sanyo 4.35v 2500mAh 16650s for my 6P. I just wonder if LG is still producing the D1s and E1s and if not, the current stocks might be aging.
My two D1s were made in August of 2013, so we're coming up on 4 years and my two E1s were made in September of 2013, so a month apart.
If they did a bit better in current handling, I'd run one of the D1s in my 3Tronics triple XP-L HI you got me, but they're somewhat anemic in that regard.
Anyhow...I remember way back, when all the cool kids were runnin' them...
Chris
It seems I'm still uneducated. I have a question about the storage environment of the batteries. We have established that the storage voltage of the batteries is around 3.6 - 3.65v. But why do you guys keep them in the fridge? What if I leave them at room temperature? And when you say the fridge, do you mean the freezer or just the regular fridge (around 4 degrees celsius)?
Thanks.
Thanks.
The storage voltage depends on the chemistry, e.g. see here. The reason for storing them at coolor termperature is that this greatly slows down self-discharge and internal degradation processes.
