My Xtar VC-4 smells bad.
Also mine only charges 18650 batteries to 4.17v. I know it is better then overcharging, but is this good for the batteries?
Cheers
4.17v is great in my opinion. I did some tests with my hobby charger and the difference between 4.2 and 4.17 was only about 3% if I recall correctly. From what I understand the batteries will last longer and be happier when charged to < 4.2.
Can’t help you with the smell, it may just be burning off some residue from the manufacturing process, how old is the charger?
As for only charging to 4.17 volts, it’s GREAT for the batteries. As I understand it, the closer you get to max capacity per charge, the shorter the life of the battery. The flip side of this is that the less MAH’s stuffed into the batteries, the sooner they need to be charged. It would be an interesting long term experiment to see where those two graphs intersect. Number of lifetime charges vs hours of useful output vs end voltage.
hmmm, lets see, I’ll need a sponsor, a fleet of batteries, a fleet of chargers with precisely controllable end voltage, a couple dozen identical flashlights… Should probably have them all in integrating spheres to watch the light output…
Ok, thanks guys on the charging cutoff information.
The VC-4 smells bad comment was in regards to “Tumbleweed48” post asking for the snort test for the strong odor.
Cheers.
Mmm, Ive ordered 25 MC1’s… First time trying out XTar. Im feeling uncomfortable 
No problem with the MC1. Simple and effective. No frills.
Thanks! 
Hi guys,
I think I might have a related problem. I’ve bought a new Xtar VC4 and went on to charge 1 AA (I don’t remember the brand) that usually holds 1600 mAh, as tested with my other charger, the Opus BT-C3400.
The thing here is that the charger keep charging the battery until about 4600 mAh were show in the display… I was afraid it was going to blow away! The voltage was at ~1.45 but it kept charging and charging (the battery was very hot).
I left the charger working in a safe spot, went to sleep and found out the next day that it stopped around 4600 mAh @ 1.5 v. Should I worry about it? How could it be possible that it putted that much mAh into the battery and it didn’t blow up?
Please let me know what you think; thanks in advance.
BTW, it was a battery that started with the “0v revival function”, i.e., other smart chargers (as the Opus) wouldn’t even recognize it because of the low voltage that it had, so I used this function from the Xtar to charge it. I don’t know if this would have anything to do with it.
4600 mAh AA! 
That’ts so! 
Any ideas of what might have been going on?
Thanks.
if i were in xtars shoes i would want to know RIGHT FN NOW! if i had a bad batch of chargers that would replicate the samsung note 7 fiasco so i could recall them,pull off the shelves and get them all back.
but thats just me.
on the good side you have to really overcharge a high quality modern cell to get a nasty outcome.like 12v
iirc thats one of the ul tests.
with whateverfire grade cells all bets are off.
Yeah, there’s source voltage, there’s the load, and there’s a series resistance in-between to limit the current.
That’s why you can take a 9V battery, 3V LED, and 1kΩ resistor, and get only 6mA through it. The voltage across the LED will read 3V, and the resistor will drop 6V.
Same like float-charging Pb-acid batteries. They’ll soak up (depending on their size) a certain amount of current without increasing their voltage, so you can hit ’em straight from a 24V bell transformer (and diode, etc.) with only an appropriate-value series resistor, and they’ll safely float away for their full service life without a hitch.
That’s why I like those cheapo 2buk chargers FT sells, because they’re so low a charging current you’d really have to leave them in for days on-end to hurt the cells.
A fast-charger, of course, needs to be WAY more critical in its source voltage.
One suggestion, or at least something on my “wish list”, is to have an option to charge a cell to only 90% capacity, for longer life at the expense of runtime.
Charging to only 4.1V (or 4.0V), say, would also leave more “headroom” in case of overcharge.
Just a thought…
Before all dogpiling on XTAR , let’s wait to hear back what their customer-service says.
I got a WK50 with a bit of a wonky switch (only intermittent problems), contacted the vendor to see if they had just a replacement switch to send, vs snailmailing everything back’n’forth, and was told to keep the light, they’d send me another (it’s on the way!), and even sent instructions with pix as to how to take apart the tailcap and play with it myself to have 2 working lights. I was sufficiently wowed.
Absolutely, it’s in XTAR’s best interests to get back the charger and find out what went wrong, even if they have to eat the cost of return postage. A few bad incidents of Li cells going supernova would make XTAR chargers the equivalent of Galaxy phones. Forget recalls (shady sellers would keep selling them anyway). What they’d lose in terms of sales just from BLFers would be probably hundreds of times the cost of the return postage.
I kinda get the feeling that one of their distributors in Canada would realise this and offer to cover return postage.
I just signed up for this replay.
Had exactly the same problem with a 0-volt Tronic AA 2500mAh battery.
Removed it from the Xtar VC4 charger after 10-12 hours 1.5v 4400mAh .
yes long term effects are unknown.everything from ruining the cell quickly to a kaboom in the future.
With a hobby charger like the I charger not sure the model and the clone versions of it. You can set it to cut off at a exact voltage like that. And during the discharge test you can set the exact cut off voltage you want to terminate at
Idk if this helps but I just received my xtar vc4 charger yesterday and straight out of the box before I even plugged it in it has that almost burnt like electronic smell so strong that it can smell it while laying in bed, sitting on my night stand right next to me. It’s strong but isnt the exact smell from burnt electronics but its close. Alot of electronics when new have strong smell to them till them break in kinda heating off the smells with regular use. Alot of glues used in the transformer wrappings and certain materials used create an odd smell. I’m an certified automotive technician and know what burnt electronics smell like and even though this is close it isn’t and at least with mine everything is fine. So far mine seems to work as advertised. Hope this helps
Also all printed circuit boards have a like glazed coating on them to protect the current paths from arcing out on foreign objects which wold create shorts, this coating has a smell that may be associated with “burnt” or “bad” electronics. After time once the coating fully cures the smell will dissapate. Sometimes “heat” from normal usage will agitate the smell for a certian period of time
Any fakes of the Xtar VC4 being sold.??
John.