XTAR VX4 Visible Mixer 1.5V/3.6V/3.7V Li-Ion 3.2V LiFePO4 1.2V Ni-MH Batteries Charger and Battery Capacity Tester

The charger is working well with my AA NiMH batteries and my 18650 cells. Measuring the capacity is particularly useful when you have a bunch of old batteries and are not sure which are working well enough to use. In my experience the charger always detected the battery type correctly and always applied the correct charge voltage. I don't know how the algorithm works, but it does work. Personally I would feel more comfortable with a switch for setting the voltage.

This is a great charger and capacity tester for Lithium (Li-Ion & LiFePO4) and NiMh batteries; it does not do alkaline, Ni-Cad, or other types of rechargeable batteries. It comes with a nice well made pouch, USB-C charge cable & AC adapter (must use included adapter for full battery charge power & functionality to the unit), and instructions. The lettering in the instructions was super small, so I had to scan it, then print it in a magnified format (see attached in English for your convenience). First, some terminology for consistency: • mWh stands for milliwatt-hours and represents the total energy a battery can store and deliver. • mAh stands for milliampere-hour and represents the battery's capacity, indicating how much electrical charge a battery can hold. I've used this unit to test several brands of rechargeable AA Li-Ion batteries (see links below for my reviews). None, not one, reached their advertised mWh capacities. In their reviews, many claimed that the batteries were "great" and lasted longer than their NiMh and Alkaline batteries, which is to be expected, however, "great" doesn't mean they lived up to their advertised capacities. This unit will definitively tell you. Lithium batteries discharge at a consistent 1.5V from beginning to end, even when the charge is very low and near 100% depletion, so a regular instant battery tester doesn't work as it will show a lithium battery as being consistently and fully charged until there was about 0% charge left (eg. a 10% charged battery would still show as 100% fully charged). However, 100% charged doesn't mean the battery is charged to it's max capacity, only that the battery has reached the limit of its storage capacity. Think of it this way: an old rechargeable battery that has a diminished capacity, will only charge up to that level, and still show 100%. This unit can do two functions: 1) charge-only, 2) determine battery charge levels (mAh and the mWh). ***You cannot just put batteries into the unit for an instant charge level test due to the above*** To just charge the batteries, plug the unit in to the wall, select the "charge" function, then put the batteries into the unit. Although it will self-detect the type of battery you put in, you can manually select it as well (it will override your selection if the battery type is different). To determine the battery's charge capacity, the unit will first fully charging the battery(s), then fully discharging them (the battery capacity levels are determined here), then fully charging them again so you can use them (C-D-C). During the discharge phase, it will continuously calculate the charge level as it depletes. When the full CDC cycle completes, the unit will display "Done" with both mAh & mWh for lithium batteries, and just mAh for NiMh batteries. Understandably, this process can take several hours depending on the actual charge capacity of the batteries; the higher the capacity, the longer it will take. The nice thing is that you can charge any number of batteries, up to 4 total, and each battery can be a different size and type (eg. AAA NiMh with AA Li-Ion and AA LiFePO4). Size is a bit larger than I expected (6.77"L x 5.11"W x 1.63"H), but with the robust displays for each battery and number of batteries it can simultaneously handle, it makes sense. Below are reviews to the Li-Ion rechargeable batteries that I've tested, none that charge close to their advertised capacities: My XTAR Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/RSUM0LDFT2FPX My SincehHoly Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/R390K7RXXBV8VN My Delgeo Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/R2OPXD8DHSCY37 My RayHom Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/R2Z9KF179P01ZH

I almost passed on this after reading a review saying it charged at a much slower rate. That person didn't take the time to look what was going on, it does. The charger takes between 9 and 10 minutes to analyze the battery at 150mA charge rate, then kicks up to full charge rate. It is only AA batteries that it does this with. Likely a safety feature looking for problematic batteries I would imagine. I mainly bought this for mobile charging when I'm away from home and I only want to carry one charger. Working great on AA batteries and 18650 Li-ion batteries as well.

Once again XTAR knocked it out off the park with this new VX4! My VP4 Dragon Plus was my go to but now doing 1.5 Lithium AA, AAA, C and D this one is fantastic. It can, at the same time have: a 21700, protected 18650, 1.5v Li-ion AA and NIMH. Charge or “grade” (which is C-D-C cycle) by pressing MODE promptly upon plugging it in. Another impressive function is the automatic setting of Amperage, but you can manually set ALL channels to do 250mA, 500mA, 1A or 2A. This is achieved by pressing the mWh/mAh button upon start up. Note ALL 4 channels will operate at that amperage regardless of chemistry or voltage. (Note if you are using a weak nimh or Li-ion AA or AAA it might limit you below 500mA or 1A depending on the cells iR. I have yet to be annoyed by this, I’ve agreed with it every time so far. It can do LiFePo4 BUT ALL CHANNELS will be LiFePo4 and forced despite sensors. FYI. This is achieved by holding the C/V button upon start up. This is the only setting I’ve seen that isn’t foolproof and could be slightly dangerous if you didn’t know what you were doing and did exactly the wrong thing. lol. Summary. The value for your money is undeniable , this has a fast charging speed at 2A on all channels (if supplied USBC PD with enough wattage and voltage) all while residing in a sleek, small and portable unit that needs nothing but a USB cord. I bought 10. Lol. Reminder. You will be unplugging it between tests to reset modes and amperage, take photos when completed because there's no memory and when bumped hard or a cell is removed, you won't see that test result again. There is no USB Out, no 9V, while there is interal resistance measurement it is not displayed(not that those should ever be trusted on a charger) and while you can change modes with out unplugging the test amperage will be automatically decided and not displayed unless unplugged and set. I wouldn't expect these features on any machine under $100 but just wanted to let you know. 10/10 rating from me and that's rare. Also the BC4 gets a 9/10 but oddly not the one in the kit with batteries(that BC4 5/10 and xtar cells 10/10 and I've tested hundreds). The version with USB C and USB A in the photo: 9/10. - at LeviMThomas fb insta