XTAR VC4 Plus 18650 Battery Charger 4 Slot li ion Fast Charger with 18W QC 3.0 Wall Charger Max 3A for 10440 16340 18650 20700 21700 32650 Ni MH AAA AA C Battery Charger Test Batteries’ Real Capacity

So I was trying to find a good battery analyzer to determine the health of my rechargeable batteries. I purchased the Xtar VC4S because it is advertised as having a grading mode that does a charge/discharge/charge cycle and gives you a mAh rating.I purchased a four pack of new batteries to test out the VC4S; they were Energizers rated at 2000mAh.The first test resulted in the batteries showing 1929/1993/1479/1448 mAh in slots 1 through 4. Immediately I realized something was wrong, since they were brand new batteries, so I put the same batteries back in different slots and tested again. The second test resulted in the batteries showing 1366/1947/1980/815 mAh. Running subsequent tests kept resulting in the batteries showing lower mAh ratings each time. The third time (same slots as the second) resulted in 729/1939/1971/625 mAh.Since this mode is supposed to fully charge the batteries as the first part of the test, there is no explanation for this result. Unfortunately the documentation is a joke- there are maybe two sentences explaining how this mode works. Therefore I must assume there are no tricks or additional steps to get it to work.So later I put the batteries back in the same slots as the initial test, and first fully charged them in CHG mode, and once again ran grading mode, and then it showed 1889/1948/1920/1955 mAh. (OK, so clearly the grading mode is not fully charging them, I thought). This proves that the batteries were not defective anyway. Although the 1889mAh reading seems a little low for a battery rated at 2000mAh and only ever having been charged a 5 times.Also the VC4S has a mode to show the internal resistance of the batteries, however simply removing the battery and reinserting it into the slot results in a different IR every time (varying by as much as 100%). It first tells me the battery is 65mΩ, and I reinsert the thing and two seconds later it tells me the battery is 30mΩ?!? Clearly this mode is worthless. I hope it is not using those same readings to compute charging factors for other modes!Unfortunately my first reaction is that the VC4S is unreliable garbage.Anyone who knows anything about engineering knows that for a test instrument to be usable- it must have accuracy and repeatability. A scale for example- must be able to determine that a sample weighs 1g, AND it must be able to do this every single time you put that same sample back on it. Accuracy without repeatability is completely useless.I was very disturbed that nobody online who reviews these chargers had bothered to test the grading mode's repeatability; they seem content just doing a single test.Thus, there is no possible way that the unit I received was working as intended. A battery does not go from 1929mAh on one test, to 687mAh and then back to 1889mAh, not if the grading mode is properly charging and load testing the battery each time. Given the poor documentation, the only possible conclusion an end user can come to- is that you just "put the batteries in the thing and press the button".For this reason, I must give it 1-star as it is useless as a battery analyzer.Unfortunately Amazon removed the ability for people to comment on reviews, after intentionally not adding the feature to mobile platforms and then lying about people "not using it" as most people switched to mobile platforms. I would really like to hear from some other users as to whether they have the same issue.Hopefully I just got a bad unit; I already ordered a replacement to test another unit, and I will keep testing with other batteries. Another bad thing is that it takes multiple days to do a complete set of tests.I have emailed the manufacturer but given the caliber of their website I will not hold out hope. I will update this review if the replacement unit works any better or if I hear from them.UPDATEGot the replacement unit and it is doing the exact same thing. I even tried a much more expensive QC power supply. See attached pics. I tried EBL batteries this time to make sure it wasn't just energizer that was causing the issue.Unfortunately the grading mode is useless unless you have days to test your batteries multiple times and then average the results while throwing out outlier values. I need a tester that will give me correct results the first time, that I can trust. I don't have time to play around with something like this. So they're both going back to amazon.Now that I have read some other users' reviews I see that I am not alone having this problem. I received a response from support in china and they recommended I try different slots and report back. No doubt they will next claim ignorance and offer to send me a replacement unit with the exact same problem. This tells me they are completely unaware of this model's failings, which seem to be consistent across multiple users who try to test NiMHs. A reputable company would have already tested the repeatability with a variety of battery types. The fact that they didn't, is highly concerning. I hope I am just being negative- but I will let the process play out.So I just ordered the EBL TCX just now and hopefully that one works better. We'll see.UPDATE IIIt is now obvious that the grading mode does not fully charge the batteries like it claims to. It is supposed to Charge-Discharge-Charge according to the instructions, giving you a reading as to how many mAh the discharge cycle took, as well as leaving you with fully charged batteries. (Unlike the more expensive xtar dragon model which actually records both cycles' mAh numbers). However I have immediately switched from grading mode (after letting it fully recharge and display green/"done") to CHG mode, and the batteries sometimes take significant time to show "full"- often taking hundreds or even thousands of mAh more. Again, there is nothing in the instruction sheet that says you should have to do this first.This is happening on both units btw.Interestingly, one EBL AA actually took 2940mAh to charge in CHG mode (after being charged by the grading mode's recharge step), which is more mAh than the battery is even rated for! No idea wtf happened there lol. Those same batteries test at around 2500mAh normally.I will continue testing in this way, fully charging in CHG mode first, and see if I still get any bad tests. So far however, it seems I am getting far fewer bad results this way.UPDATE IIISo it seems that the grading mode actually works very well- iff you fully charge the batteries first in charge mode. It is a shame that most people will not undergo the necessary testing to figure this out on their own. Clearly the unit has the capability to test Ni-MHs properly, just not the algorithm.It actually works much better than the EBL TC-X, which overcharges the batteries and rates them hundreds of mAh too high.Shame it is so rare that a company actually takes the time to properly test their new tech before releasing it to the market.

Bought 6 to have a semi-mobile 18650 cycled/tester. After around 500 cells(~130 cycles of potential batteries on the array: 4cells per charger x 130 completed charge ->discharge>recharge tests) and then completely different testing rig for the same cells the results are at least consistent between the Xtar charger testers and correlate well compared to other testers. My only complaints are: the default 3A charge current when only 1 cell is installed(2A for 2 cells, 1A for 3 or 4 cells), and second that if a bad or questionable cell has a high self-discharge from 4.2v, after completing the discharge>charge test it erases the tested discharge capacity like the cell was removed and begins the whole test again as if cell was removed and installed again. It wastes the cycle for that cell. I began simply waiting for the discharge test to finish then changing the mode to capacity charge. (That stops the test cycle from starting over again)Overall, good charger and decent tester for a good price. Yes, there are better testers and chargers but for a wannabe like me seems to work well enough for a month worth of constant use.

I wanted a charger that could tell me what the capacity of my 18650's I bought a Ex-medical unit that had 25 of them in it and I need a way to tell how good each cell still is OR if I need to recycle the bad ones, This charger does that. I saw a person say it can be used as a power bank? NO it can't there's no connection for output power. Even though it's a good charger and gives me all the info I need on a cell, I even like the display, it's easy to read and looks good. it came with a wall USB power supply and cable everything I needed to start going through the cells.

I've bought several different battery chargers over the years and this one has been a real treat.Not only does it come with a 3amp wall charger, but it also has a proper capacity test feature.I think the only other features I'd want are the ability to discharge the batteries into another battery charger (so as to waste less power during the discharge cycle), oh and it would be nice if the charger could stay powered on even when disconnected from power (as long as there are batteries still in the unit (That way the capacity numbers aren't erased if I accidentally unplug the power without writing them down))But again, this is absolutely a 5 start product!

Bought this for its capacity test (Grade) feature. Upon receiving I immediately put a vtc6 and 25r in that have only been cycled once each in to test. Woke up the next morning to see it was finished testing. Very happy with this charger/tester. Picture attached to show results.Edit: Have now used the “Store” feature along with regular charging. The LCD dials are more a rough approximation than they are terribly accurate, but perfectly acceptable nonetheless. Still very happy with the XTAR VC4S.

I'm really happy with the performance of this charger. I was looking for a charger that could handle reclaimed over discharged 18650 batteries and this one handles them really well. It charges much faster than all of my other chargers and can charge a single battery at 3A, two at 2A, or three or four at 0.5A depending on the capability of the batteries. I haven't tested the battery capacity feature yet but everything else works exactly as I needed it to. Overall, very happy.

Ok so I just got this and I charged my 18650s and I'm charging my 26650 next will my 21700 this thing is awesome mine DID come with 3.0 QC wall adaptor like it said in the description get it while it's this price and in the combo it is a killer deal. I wanted to do a quick review because I had such a hard time buying it especially because of the other review but it's such a good charger that I need to put this out help other people like I have been helped in the past bought with my own hard money and I will update if this thing turns in to a pumpkin 😂 be safe be good.

I only used this charger twice maybe before it was stored for some time (~ 6 months). When I started using it again it would charge empty/partially empty batteries only to 40mAh before showing as FULL. And these batteries have a capacity of 1,200 mAh. This is a piece of garbage and waste of resources and time. Looks good but it does not what is supposed to do. No response from the manufacturer on this matter either so say good buy to after sales support as well.

This is the best 4-bay charger I’ve ever owned. The 2 amp charging for my 18650s is gold! Love the Grad. function as well. Definitely recommended!

Good so far. I like that grading feature to see if the batteries are still good. Can grade in all 4 spots. Only had 1 issue grading 4 lithium batteries at the same time where the machine just froze. Had to unplug to test with fewer batteries and all was good.

The product was working well but stopped working after 4 months.

Charges very well. Interresting displays. I like the function that provides a grade for each battery.