XTAR VC2 (help)

Good afternoon and Happy Valentine’s Day!
I now own two new XTAR VC2’s! Love them!
I have a question about the “mah” readout, please.
I’m new to this, so please forgive.
When I plug in a battery, it will read say 3.6 volts, later, it will make it up to 4.0 volts. Perfect.
It’s a Sofirn 3000 mah 18650.
How does the MAH part work? I took my batteries out when they at something like 1600 mah.
I’m suppose to leave them in ’till they reach something more like 3000 mah?
Am I thinking correctly?
They can reach the proper voltage before they reach the proper mah?

It only counts what it charges. So if you put in a half depleted battery then yes full would be adding another 1500mAh if it is 3000mAh rating wise (kind of like pumping gas the pump is only telling you what it’s putting it, it doesn’t know how big your tank is and stops when it’s full). You can run down the battery until dead and then recharge it that will tell you the full capacity of the battery.

Awesome! Thanks so much for the explanation! Boom! I appreciate it!

One way to know how many mAh your batteries are able to hold a charger that does discharge capacity testing can be used

The Xtar VC2/VC4 cannot do this but the Xtar VC4S is one of several chargers that can perform the capacity test and is easier on your wallet than other ones.

I have this charger. It will say FULL when done, and it will hit 4.2V before displaying FULL. The only detractor with this charger is it is a .5 amp charger only, which is OK if you have time to kill while charging or rotating batteries. The VC2S does .5/1/2 amp charging, and can be used as a power bank.

Awesome. I appreciate the information.

Most excellent. I also have the Sofirn charger that came with my Q8. It simply turns from red to green. Ha!

I don't think the VC2S can do a capacity test.You'll need the VC4S for it.

Slow charging is a good thing.

When does it say “FULL”? Where on the little screen? My batteries are 3.7 v and the charger is still going at 4.2 v.
I am charging unprotected Sofirn 3.7v 3000mah button top 18650’s.

Bad advice since the Sofirn 18650 3000mAh is unprotected. Never discharge an 18650 below 2.5 - 2.75 volts (varies on models) but to be safe people usually say 3 volts. Discharging below this point will damage your batteries and it’s not recommended to recharge them.

“mAh display flashes ”Full” when the corresponding battery is full. ”

Link

Even with unprotected batteries?

Yes. Why would that matter?

Whether button top or flat top,whether protected or unprotected the charger will terminate the charging current when the cutoff voltage is reached.

Some chargers will stop charging Li-ion 18650 when the voltage reaches 4.15V while others can terminate anywhere between 4.15V and 4.20V

Not charging 18650 cells to the Max 4.2V will prolong the usable life of the cells.

batteries that have protection protect from short circuit, over charge, over discharge, over current. Chargers these days will stop at 4.2 volts or close to it so you don’t have to worry about overcharging an unprotected battery

A typical Li-Ion charger uses CC/CV logic, which means in the second part of the charging cycle voltage stays constant while the current keeps dropping. Charging is terminated when the current drops below a certain value while keeping voltage the same.

I appreciate all of the valuable information. Thanks everyone.

Since you are in Houston may I suggest you to call or visit IMRbatteries for 1st hand assistance if needed.

5631 Braxton Dr
Houston, TX 77036
1-800-977-3976

Now I have a 26650 battery that I’m charging. It’s 5000mah & 3.7v.
So glad I have this Xtar VC2.
So when it’s “full” it should read “full” where the mah is displayed? Every battery should do this??

Yes, every single 3.6 or 3.7v lithium battery will show full on the display