XTAR VC4SL charger review

Batteries and Chargers Chargers
1

Not all flashlights have internal charging, so it’s better to have a proper charger around to charge all your batteries.

XTAR has sent me one of their new chargers for review, the VC4SL. Thank you very much!




Overall it’s similar to the predecessor, the VC4S, but it is longer to support protected 21700 batteries, allows you to set the charging current manually and connects via USB-C.



The charger comes with a protective pouch, a USB A-C cable and a manual in eleven languages. The 18 W QuickCharge USB power supply shown in the picture is available separately and was supplied by XTAR for this review.



With 155 x 115 x 35 mm it is relatively big, but I’m used two dual-slot chargers and this can handle very big batteries as well. So not really a surprise.



Mode, voltage and charging current and other details can be seen on a white/blue/black LCD screen. Right below there are two buttons “Curr” and “Mode” as well as four red/green status LEDs, one for each slot (sadly very dim).

After 60 seconds the screen dims its brightness. By pressing and holding the “Curr” button it can be switched off completely. Good if you don’t want to be disturbed by the charger over night.



It is powered via a USB-C port at the rear side. While a simple 5 V power supply will work (3 A recommended), the full potential is unleashed with a 9 V / 2 A QuickCharge compatible power supply.



The XTAR VC4SL can charge two types of batteries: 3.6/3.7 V li-ion and NiMH. It is compatible with all sizes that physically fit into the device and can be charged with at least 250 mA.



This means: All batteries from 32.5 to 77.5 mm, thus also long protected 21700! Short 18350 fit as well. Cells with a larger diameter (26650 and more) fit into the two outer slots. There’s enough space to charge smaller cells together with 26650.

XTAR mentions following sizes in its manual:
Li-Ion: 10440, 14500, 14650, 16340, 17335, 17500, 17670, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650, 32650
NiMH: AAAA, AAA, AA, A, SC, C, D

There’s just a small issue with very thin batteries like AAA: They slip under the little nub of the sliding contact and don’t make contact. Raising them a bit with the help of a spacer like shown in the image works, but it doesn’t look nice.



After insertion of the batteries the charger measures their internal resistance to select the appropriate charging current automatically. Afterwards the selected current is shown together with the current voltage in steps on the graphical display.
I’ve noticed that the displayed voltage is higher than in reality: When the display switches to 4.20 V, the real voltage is only 3.9 V (measured in the charger).

Below the graphical display there is a digital display with additional data that can be switched by a short press of the Mode button:

  • Capacity (Cap.): Charged capacity since start in mAh. The last digit blinks.
  • Current (Cur.): Actual charging current in mA. Not really helpful for NiMH batteries because they are charged in pulses and the displayed current jumps around all the time.
  • Internal resistance (IR): Approximated internal resistance in mΩ.

Measurement of the internal resistance is not very accurate. Just move the battery around and it might show a smaller value. But if the contact is good the values are more or less consistent.

By default the charging current is determined automatically from the internal resistance. For my taste the chosen current is too big, e.g. 2 A for an old Sanyo NCR18650GA or also 2 A for an Eneloop AA.
The charging current can be changed manually by pressing the “Curr” button to 3 / 2 / 1 / 0.5 / 0.25 A – but only for all slots together! It is not possible to change it for each slot individually and you can only charge batteries with similar properties together. Not good.
NiMH batteries are charged at 160 mA for the first three and a half minutes (to detect deeply discharged li-ion?). Then the selected current is used.

After the charging has finished the display shows FULL together with the charged capacity and the LED switches to green. Li-ion batteries were charged to about 4.16 V in my tests.

There are additional features in the VC4SL:

  • Grading (Grad.): Charge, discharge and charge the battery to measure its capacity.
  • Store mode (Store): Charge or discharge to 3.7 V for storage.



The XTAR VC4SL is a simple, easy to use charger for up to four li-ion/NiMH batteries, supporting protected 21700 cells. The store mode comes in handy, the IR measurement is enough to detect very bad batteries. I’d like to see a digital voltage display, because the graphical one is not very accurate.

Manual selection of the charging current is of limited use because it can be set only for all slots together. Also the automatically chosen current is a bit high for my taste.

Overall I think it’s a good charger. You can get it here on AliExpress.

2

Hi there,

thank you for the review.

I bought the VC4SL and used my 5V/2A power supply from my Smartphone and it looks like it work, but I have a strange experience with this combination. It seems the two inner slots work fine but the outer slots stop the charging too early. I used 4 AAA cells with 950mAh, 500mA charge current. The inner slots load over 700mAh, which i OK I guess, but the outer slots stop charging <400mAh.

I also use the Grading function and the right slot shows with an older AAA a capacity of 260mAh which is to low, my S4 showed 685mAh. If I use the inner slots the results from S4 and VC4SL are more similar, the VC4SL shows always a higher capacity than the S4.

I dont have a QC3.0 power supply to test, but I´m not sure whether it´s the reason for this behavior.

3

No 26800!!! :rage: :rage: :rage:

4

@Johnny_Bravo
Try it with li-ion batteries. These multi chargers have only rudimentary support for NiMH, sadly. Also I’ve noticed that the capacity measurement during charging seems to take the internal resistance into account which causes different displayed capacity for two batteries with the same current and charging time.

@puglife2
Not officially, it’s just slightly too short. You can remove some of the plastic at the bottom and they can fit.

5

I found a little interesting fact with this charger.
If I placed the batteries before plugged to the power source, charger might not working properly.

It’s not a minus for me, just something to be aware of. Other than that, this is by far the best charger to my needs.

6

I won this charger in the XTAR Christmas GAW on Facebook and Instagram.
No, as an avid non-social-media person, I have not fallen off the wagon.
XTAR very friendly allowed me to deliver my input via their company website.

And now I’m looking at it. It comes with a lot of “bling” on the display.
My personal choice would have been to make that display a bit less abundant.
But when you look past that it is a very nice straight forward 4-slot charger.
If I need a charger with more elaborate tricks, I’ll still have my OPUS.
But this is a charger you can almost operate with your eyes closed.
Which can come in handy since lights with 3, or 4, or more batteries are on the rise.

My personal opinion is that everybody should at least have one charger like this.
If you discharge a Li-ION battery too far, it gets “out of reach” of most chargers.
Because at 2.X V it is considered to be a loaded Ni-MH and it stops charging it.
Where other chargers often fail, a charger like this probably can revive it.
I don’t recommend to do this with batteries you dig up from an old drawer.
But if you need that last bit of energy and have no spare on you, it can be saved.
I know that because my XTAR VC2Plus Master and I go back a looong time

BTW: nice review SammysHP.

7

I have only a few Li-ION, maybe I tets it some day :wink:

The Grad-function measures at discharge, or am I´m wrong?

It confused me that the results in the inner slots looks realistic, a bit more than my S4 shows but less than my C3100 shows. But I guess not all chargers load exactly the same mAh in the cells.

8

Testet a bit again, the 4th Slot don´t charged so far one cell to full and shows at Grad.Function also to less values.

The 1st slot worked at this try, I wonder whether it depend on the number of used cells or selected current. Mayb I get soon a QC3.0-PSU and test it again.

9

Update

I ordered a QC3.0-Power supply from Xtar and tried it again.

A Mediarange AA 2100mA was loaded like it should loaded

All other AAA I tried stopped at 50% load or below. Strange, some weeks ago all AAA in bay 1-3 were loaded correctly

This charger seems to be extreme bad for NiMH

10

Managed to load some 3 AA NiMH successfully, dunno how

But no matter which load current I selected, it was loaded at 500mA

So this charger still get the title worst charger ever (for NiMH)

11

I also notice this issue with early termination during charging with NiMH batteries (I use both AA and AAA, Eneloop and Ikea Ladda).

I tried contacting Xtar support, and their reply was:
“The main reason, according to our technician, is due to incompatibility. ”

I’m trying to get some more information as to what this means.

12

Thank you for the info.

Eneloop/Ladda are the reference, if Xtar is overwhelmed with it -> Bad products by Xtar

13

I bought this charger shortly after release. Keep reading bad stuff about it. Which charger would you guys recommend?

14

I don’t want to hijack this thread since I think SammysHP’s review should be the focus. I’ve started a new thread here to continue the discussion:
https://budgetlightforum.com/t/-/70506

15

What IR measurement is considered bad battery?

16

I think we really need HKJ to come out of semi retirement and review this charger.

17

I´m not sure if it makes sense. It will be no better charger after the review.

I would be more interested in reviews of newer and upcoming chargers. Vapcell seems to be interested to make chargers with properties ppl want

18

Today I bought Xtar vc4 plus which is considered to be the retail version of xtar vc4sl with same specifications.

I just placed a Chinese AA Eneloop which is probably in a bad condition, aged and has been over discharged before. Cell is rated 1900 mah and prior to charging it dropped to 0.9V while being used in a wireless mouse which draws very low current so you can consider it totally depleted. Charger measured 60 miliohm and started with 2A. It terminated early at 130 mAh. I pulled it out just after termination and measured voltage, it was 1.45 V and was dropping so fast so it probably reached 1.55V and that’s why it was terminated. When I reinserted it, internal resistance was measured 170 miliohms. So probably charger didn’t terminate early in vain. This time it decreased charge current to 500mA and it’s still charging while I’m writing this message.
So I guess the reason why vc4sl and vc4 plus terminates early is because temporarily internal resistance increases and this also increases total cell voltage. Since charger cares for instantaneous internal resistance but not a moving average of resistance nor an average value, it terminates early.
This can probably be avoided by choosing a lower charge current.
I wish Xtar brought more customization options to its chargers.

19

I would like to add something more after using the grade function for the first time. I have a very old, many times depleted, over discharged 2700 mah cell. Its internal resistance was measured 760 miliohms. Its capacity was measured 370 mAh. And it stayed at 1V almost from the beginning of discharge so these results were expected. When charging it also terminated fast so I guess charger was able to terminate very old, high resistance cell properly.

20

But it terminates most cells in good conditions to early, my own experience

Don´t think my VC4SL is faulty, because other ppl have the same poblem. And some other Xtar which tested at HKJ were also unusable for NiMH

And Grade is extremely slow