XTAR VC4 Plus Battery 3A Fast Charger, 4 Bay Rechargeable Battery Charger Extend Version for 3.6V 3.7V 18650/20700/21700 Li-ion IMR INR ICR for 1.2V AAA SC Ni-MH Ni-CD with QC3.0 Adapter

Charges all common battery's mix and match. Already using it and it works perfectly

This thing chargers up my 18650 so fast, that I wonder sometimes, if it has really even finished charging them up. Now, to a side note. It is not a concern to me, but my older charger would charge aa and triple a batteries, where as this one will sometimes and sometimes not charge them. I don't know if it is a fault or does not really know how to deal with these type of batteries. I don't really care, as I already have a charger for regular batteries anyway. Just something I noticed while trying to charge my aa batteries on it, just to keep me from having to walk to the back room to put them on charge.

I have been very happy with this charger, I use it weekly to charge both my aa and aaa batteries and 18650 lithiums. I like the store feature and test feature, which allowed me to go through my dozens of rechargeable batteries to group them based on capacity. This way things like headlamps can get the best batteries, and the tired ones go into the tv remote.

Fantastic Product. Since receiving I've evaluated, graded, and charged/discharged 50 18650's. This seems to be a workhorse, and great product. But all is not perfect. Here are the minor flaws as I've observed.1. IR (Internal Resistance) measurement is inconsistent among slots. This is demonstrated in the pictures supplied. This seems to be even worse on my VC8, than this VC4 Plus but both products are affected. To get an accurate IR measurement -- when a measurement is suspect -- take multiple measurements across different slots then use the average or more likley, minimum result.2. While the included QC is OK; this is still current limited. Only able to charge 1A across 4 batteries or 4A total. Not horrible, but a bit more would be welcome. However, being USB/DC Powered instead of external AC Brick or AC power supply is great.3. Discharge Ability is limited. Has a relatively slow discharge rate used when grading or storing a battery.4. While not listed, it unsurprisingly, also charge 20650 cells. These are somewhat rare, but found in several tool batteries.5. While seemingly reasonably-sturdily built, it does not get terribly hot either (it does get warm however). However, there is no evidence of UL other type-acceptance on the product. While "probably OK", lack of said (legal) marking is suspect -- best case cost cutting / China Normal. Worse case, it wont pass.. It's probably best to put it in a LiPO charging bag/box for peace of mind protection.6. Nice Display. Although, I'm not hot on the 'dumb-ed down' gas-guage voltage display; I suspect I'm in the minority here.. would prefer to have some advanced display optons to just display *all* info at once for each slot. I'd pay a few $ more for a charger that had this but otherwise identical.Overall though, for a 'cheap' (<$40) charger, this is good and probably the one to get in this category. Good job XTAR.

I've salvaged several old battery packs for power tools, where one cell or another got low for some reason. In some cases I've had to disassemble the battery pack to get the cells out, but I've also used alligator clips and magnets (to attach to this charger's positive terminal) to connect directly to cells in a pack and test it, followed by getting it charged up.In cases where the cell in a pack really is dead, this tester shows that, and no amount of charging will help them out (maybe a blown safety valve) but for batteries that are merely low, it may start out charging a lithium ion as if it were a nicad if the charge on it was that low, but after a little bit it sees that it'll take more and switches to lithium ion just fine and charges it as such.Speaking of nicads, I haven't really used this for any of my old nicad batteries but I really should do that. I have 2 older chargers that just do that and it'd be great to cleanup my work area and retire those old ones. This one probably does a much better job of it, and being able to test the capacity is a cool feature my old ones don't have.

This charger is a dangerous improperly designed fire hazard. It does not properly negotiate USB protocols.USB devices are supposed to automatically negotiate the proper usb protocols that control the electrical parameters. This is why the myriads of usb protocols work with each other, like how an electronic device that is capable of accepting multiple amps of fast charge current with a compatible wall adapter will still charge perfectly fine at reduced current on any computer usb port without frying it. This charger does not do that. It will draw as much current as it is set to regardless of the limits of the USB port it is connected to.I hooked this charger up to a usb3.1 type A port on my motherboard (under the assumption that it will properly negotiate and control current draw within the design specifications of the USB port) and it ended up frying the motherboard USB ports, (burning electronics smell and all) and causing the motherboard to auto shutdown from detecting a perpetual overcurrent state, rendering the entire motherboard unusable.Since this charger seems to basically acts as a dumb variable resistor to the power source, I am very concerned about how it will affect even the wall adapters it is connected to. It is possible that at a high enough charger current setting, (this charger has a 3000ma max setting, with four battery slots), it may be possible that the charger draws excessive current from the wall adapter, causing it to overheat and potentially cause a fire.This is a shame since this charger has so many great features. Unfortunately it fails at the very basics of functionality and design safety.