Xtar's VC2s is a great little charger.

264

Newly Enlightened
Joined
Sep 6, 2011
Messages
39
Location
USA
Before I found Xtar battery chargers I had gone through various expensive AA-D size NiMh chargers that were cheaply made and provided poor performance. When I needed to charge my first 18650 battery because I got a fancy flashlight I choose an Xtar battery charger for two reasons. Good product reviews and I simply thought the name was cool. My first Xtar chargers were just able to charged lithium ion batteries. What I use now is Xtar's VC4 & VC2 plus chargers because they can handle NiMh batteries as well as lithium ion. Xtar offered to send me a charger for free to review so I choose the new VC2s because it is most like the older VC2 plus.

  1. Any USB to micro USB cord can be used to connect the power supply to charger.
  2. The charger decides which charging current is best for each individual battery.
  3. The charger can measure each batteries internal resistance in M ohms, and capacity in mAh.
  4. The display can also show the charging current given in milliamps.
  5. Best of all the batteries become only slightly warm at most during the charge cycle because the VC2s lowers the current if it senses the battery or batteries are becoming warm.
  6. The VC2s takes the battery to its maximum voltage. If it's a standard 18650 that is 4.2 volts. But then once the battery is fully charged it brings the batteries voltage down to 4.15 volts. I think to help safe guard any device that uses a lithium battery that cannot handle a full 4.2 volts.
  7. The charging cycle starts with just a milliamp or two and gradually increases the current to a base current of 500ma, 1 amp, or 2 amps. The charging voltage matches the batteries initial voltage and increases during the charge cycle. The batteries I charged were:A single Xtar 18650 2900mAh 10amp High Discharge Battery.
    1. The battery voltage the night before the test was 2.46 volts. The day of the charge the battery voltage was back up to 3.00 volts.
    2. Internal resistance was measured as 81M ohms.
    3. Battery capacity was measured as 2539 mAh.
    4. Charging current was never greater than 500ma.
    5. Time needed to reach a full charge was 5 hours and 39 minutes.
    A single IRC18650-26F protected button top battery.
    1. Battery starting voltage was 3.53 volts.
    2. Internal resistance was measured as 61M ohms.
    3. Max charging current was 1.7 amps.
    4. Capacity was measured as 2704 mAh.
    5. Time needed for battery to reach a full charge was 3 hours and 20 minutes.
    A Pair of Samsung 30Q unprotected 18650 flat top batteries. Cells were kept depleted for 48 hours.
    1. Cell #1 starting voltage was 3.52 volts.
    2. Cell #2 starting voltage was 3.53 volts.
    3. Max charging current for each cell was 1 amp.
    4. Internal resistance for cell #1 was measured as 49M ohms.
    5. Internal resistance for cell #2 was measured as 51M ohms.
    6. Capacity measured for cell #1 was 2139 mAh.
    7. Capacity measured for cell #2 was 2062 mAh.
    8. Cell #1 needed 3 hours to reach full charge.
    9. Cell #2 needed 2 hours and 44 minutes to reach a full charge.
    A pair of Energizer NiMh 1400mAh AA cells.
    1. Starting voltage for both cells were 1.1 volts.
    2. Starting current for both cells were 200mAh.
    3. Cell #1 max charging current was 1 amp.
    4. Cell #2 max charging current was 500mAh.
    5. Internal resistance for cell #1 was measured as 73M ohms.
    6. Internal resistance for cell #2 was measured as 100M ohms.
    7. Capacity measured for cell #1 as 831mAh.
    8. Capacity measured for cell #2 as 1237 mAh.
    9. Cell #1 needed 1 hour and 44 minutes to reach a full charge.
    10. Cell #2 needed 3 hours and 20 minutes to reach a full charge.
    A Pair of new Xtar 800mAh 14500 protected batteries.
    1. I did not check starting voltage for either battery.
    2. The charging current for cell #1 was 397 ma.
    3. The charging current for cell #2 was 331ma.
    4. Internal resistance for cell #1 was measured as 116M ohms.
    5. Internal resistance for cell #2 was measured as 190M ohms.
    6. The time needed for cell #1 to reach a full charge was 48 minutes.
    7. The time needed for cell #2 to reach a full charge was 50 minutes.
    What I like about the charger is:
    1. Batteries do not become hot during the charging cycle.
    2. Charger does not need a proprietary power cord.
    3. Charger brings down battery voltage to 4.15 volts.
    4. Charging current is tailored to each battery. No more guesswork on my part.
    Later this month I am going to charge some of the batteries once more using the VC2s and compare charging time, capacity, and internal resistance. New batteries I can understand having a lower capacity for the first charge because they are partially charged already. I think I altered the the capacity and internal resistance measurements by pressing the function button to often as the charge began for all the other batteries. My bad. Also I tried to post the images I have of the display for each battery charge but could not get then to post correctly. Hence they are in order but will be in post 2.
    My one big complaint about the charger is: It is near impossible to remove any 18650 battery because there is not enough room to do so gracefully. You need a small flat head screwdriver to lift the battery out. However inserting batteries into the VC2s is a breeze and any battery small than 18650 are easy to remove.
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Nev

Banned
Joined
Mar 25, 2017
Messages
195
Why do you like it if the charger brings the voltage down to 4.15volts?
A full battery when taken off the charger should be 4.2 & settle to something like 4.18.
 

peter yetman

Flashlight Enthusiast
Joined
Mar 23, 2014
Messages
5,100
Location
North Norfolk UK
To be honest 5/100 of a volt is negligible and probably not within the accuracy of most DMMs or chargers.
On a 2500mah cell it's equivalent to a loss of 30mah. At a draw of 1 amp that's a difference of less than 2 minutes runtime.

P
 
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Nev

Banned
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Mar 25, 2017
Messages
195
When I take Q30's from my gyr all88 the charger said 4.2volts but they were really 4.7 ,I then put them on the skyrc mc3000 & it put another 100-150 mah in.
 

264

Newly Enlightened
Joined
Sep 6, 2011
Messages
39
Location
USA
Why do you like it if the charger brings the voltage down to 4.15volts?
A full battery when taken off the charger should be 4.2 & settle to something like 4.18.

I thought that maybe it lengthens the overall service life of the battery since the last few minutes of the charge is the hardest on the battery(s).
 

264

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Joined
Sep 6, 2011
Messages
39
Location
USA
More testing this weekend. December 29-31, 2018. Will test the power bank function charging my tablet. Charge and discharge a completely different pair of batteries. Side by side charging of the VC2s and VC2 plus. Which one is faster? Checking the anti-counterfeit serial number and displaying the result. I will not be doing anything silly like running over the charger with a four wheeler or an immersion test in water as some testers do to flashlights.
 

264

Newly Enlightened
Joined
Sep 6, 2011
Messages
39
Location
USA
When I take Q30's from my gyr all88 the charger said 4.2volts but they were really 4.7 ,I then put them on the skyrc mc3000 & it put another 100-150 mah in.

Last I heard it is not recommended to overcharge Lithium Ion cells. 4.7 volts is overcharged. Cells could go boom and catch fire at that voltage to my understanding. Volt meters can be inaccurate either handheld or when incorporated in chargers. Does your Skyrc MC3000 display the voltage of batteries? I am still a bit afraid of lithium Ion batteries. You are brave Nev. Peace.
 

ven

Flashaholic
Joined
Oct 17, 2013
Messages
22,533
Location
Manchester UK
Most are + or - 0.05v, so 4.15 to 4.25 is actually in spec, nearer 4.2 is of course more desirable. I have charged by mistake 4.2v cells to 4.35 with no noticeable issue. They are tested to much higher voltages(not recommended of course and avoid doing so). I also check several cells off each bay and verify the voltage by MM. Then i have confidence in the charger, also that it terminates at 4.2v. I also leave the cell/s in for a period of time, also to make sure terminated and not carrying on charging(you know, those times you forget to remove or are not there every second of charging.................most of the time for me!).

4.7 is far too high if it is verified with a trusted MM or other charger. I would stop using/return if it is proven for sure. It will drastically reduce the cycle life of your cells, there for costing more money than buying another charger. Not only that, if the flashlight(or other device) is a little V fussy, it could damage a driver or LED even. As some drivers dont like more than a max of 4.5v iirc.

Cheers
 

264

Newly Enlightened
Joined
Sep 6, 2011
Messages
39
Location
USA
More testing this weekend. December 29-31, 2018. Will test the power bank function charging my tablet. Charge and discharge a completely different pair of batteries. Side by side charging of the VC2s and VC2 plus. Which one is faster? Checking the anti-counterfeit serial number and displaying the result. I will not be doing anything silly like running over the charger with a four wheeler or an immersion test in water as some testers do to flashlights.
45555885575_e0e446cd85_c.jpg
[/URL]P_20181226_031426_LL by James Richardson, on Flickr[/IMG]



These are the batteries that I will be testing this weekend. I will allow my ASUS tablet to run down to 15% then I will use these batteries in this PB2 to charge the tablet. I will keep the batteries plugged in till the charger reads 0%. Posting images of the batteries charging the ASUS and the depleted batteries voltage. Then a trip to the new VC2s charger to charge. Images to be posted are:

  1. Time it takes to reach a full charge.
  2. Each batteries voltage according to my Ideal 61- 310 meter and VC2s.
    I will wait 24 hours with the batteries in a plastic case before refilling the ASUS.
  3. The pairs charge according to the PB2.
  4. The display of the PB2 after one minute of charging.
  5. Time it takes to charge my tablet from 15-100%.
  6. Time it takes to recharge depleted cells in the VC2s
  7. Time it takes the VC2s power bank to refill my tablet from 15-100%


These are the batteries that I will be testing this weekend. I will allow my ASUS tablet to run down to 15% then I will use these batteries in this PB2 to charge the tablet. I will keep the batteries plugged in till the charger reads 0%. Posting images of the batteries charging the ASUS and the depleted batteries voltage. Then a trip to the new VC2s charger to charge. Images to be posted are:

  1. Time it takes to reach a full charge.
  2. Each batteries voltage according to my Ideal 61- 310 meter and VC2s.
    I will wait 24 hours with the batteries in a plastic case before refilling the ASUS.
  3. The pairs charge according to the PB2.
  4. The display of the PB2 after one minute of charging.
  5. Time it takes to charge my tablet from 15-100%.
  6. Time it takes to recharge depleted cells in the VC2s
  7. Time it takes the VC2s power bank to refill my tablet from 15-100%
 

264

Newly Enlightened
Joined
Sep 6, 2011
Messages
39
Location
USA
45555885575_e0e446cd85_c.jpg
[/URL]P_20181226_031426_LL by James Richardson, on Flickr[/IMG]



These are the batteries that I will be testing this weekend. I will allow my ASUS tablet to run down to 15% then I will use these batteries in this PB2 to charge the tablet. I will keep the batteries plugged in till the charger reads 0%. Posting images of the batteries charging the ASUS and the depleted batteries voltage. Then a trip to the new VC2s charger to charge. Images to be posted are:

  1. Time it takes to reach a full charge.
  2. Each batteries voltage according to my Ideal 61- 310 meter and VC2s.
    I will wait 24 hours with the batteries in a plastic case before refilling the ASUS.
  3. The pairs charge according to the PB2.
  4. The display of the PB2 after one minute of charging.
  5. Time it takes to charge my tablet from 15-100%.
  6. Time it takes to recharge depleted cells in the VC2s
  7. Time it takes the VC2s power bank to refill my tablet from 15-100%


These are the batteries that I will be testing this weekend. I will allow my ASUS tablet to run down to 15% then I will use these batteries in this PB2 to charge the tablet. I will keep the batteries plugged in till the charger reads 0%. Posting images of the batteries charging the ASUS and the depleted batteries voltage. Then a trip to the new VC2s charger to charge. Images to be posted are:

  1. Time it takes to reach a full charge.
  2. Each batteries voltage according to my Ideal 61- 310 meter and VC2s.
    I will wait 24 hours with the batteries in a plastic case before refilling the ASUS.
  3. The pairs charge according to the PB2.
  4. The display of the PB2 after one minute of charging.
  5. Time it takes to charge my tablet from 15-100%.
  6. Time it takes to recharge depleted cells in the VC2s
  7. Time it takes the VC2s power bank to refill my tablet from 15-100%

I just received the VC2s I purchased from Amazon. The box the charger arrived in looks like the one I received direct from Xtar. The one difference is that the anti-counterfeit sticker is on the box and not on the charger itself. The anti-counterfeit numbers passed the look up as authentic on Xtar's website. The one big difference in the charger itself. The logo on the charger reads "Xtar VC2 2019" and not Xtar VC2S like my first charger. The outer dimensions of the charge are the same as the first one. The display looks identical. The sticker on the back of the box has an identical warranty/serial number as on the box.

Charging the Pair of NCR18650NF Batteries-BAY ONE

#1 3:40:39 Charging Time.

  1. 58M ohms Internal Resistance.
  2. 3290mAh Capacity
Charging the Pair of NCR18650NF Batteries-BAY TWO


  1. 3:17:27 Charging Time.
  2. 60M ohms Internal Resistance.
  3. 2890mAh Capacity


    In my haste I forgot to measure the voltage of the depleted batteries. According to my PB2 and the new VC2s the resting voltage was 3 volts. The pair did not at all become hot or overly warm during their charging. They were just slightly warm. When I removed them from the charger the machine said both had reached 4.2 volts. The charge voltage slowly increased from 3 volts to 4.2 volts during the charge. The charge current started at 1ma and top out at 1015ma. After the batteries reached 4.2volts the charging current was automatically reduced by the VC2s charger for roughly ½ hour till it reached 0 current.
    After 22 hours I measured the resting voltage of each cell. Both cells had a resting voltage of 4.16volts. I then placed the pair in my Soshine power bank and began to charge my tablet. After one minute the Soshine display read 95%. The cells were fully charged by the VC2S and held their charge under load with no problem. I then placed the pair in the VC2S and used it as a power bank. Once the cell in bay one was depleted the machine automatically switched to the cell in bay two to charge the tablet. I then connected the VC2S to a USB power supply. The machine switched to charging the cells and my tablet with no problem.
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