AAA Rechargeable Lithium Batteries, 4 Pack 1.5V Kratax 1100mWh Li-ion Triple A Batteries with Fast Battery Charger, Constant Voltage Output, 1600 Cycles Long-Lasting for Household and Office Devices

> After several weeks, and each battery having been recharged several times, the charger and all 4 batteries are working well. > Charges fast, especially if you have a 2amp power source (see below). Presumably, you can leave the batteries in the charger when not in use (as is the case with "smart" NiMH chargers) --- but I've never found this explicitly stated. > Capacity — Adequate, comparable to NiCd or NiMH. But, more of that capacity may be usable with rechargeable lithiums (see below). Beware that Kratax and other rechargeable lithium battery vendors rate the batteries in mWh, rather than standard MAh. 1100mWh = 733 MAh --- which is about right for a rechargeable AAA battery whether NiHM or Lithium. > Life per charge — depends on your equipment. Some equipment won’t work properly with less than 1 volt. For NiMH batteries which start with only 1.2 volts, the voltage may drop below 1 volt with ⅔ of the charge still remaining unused. For non-rechargeable alkalines, which start at 1.5 volts, the voltage may drop below 1 volt with ½–⅓ of the charge still remaining unused. Lithiums discharge at 1.5 volts until empty — so the full charge can be used. But, on equipment which works well with only 0.5 volts, you might not notice much difference between NiMH and lithiums. In my MP3 player, the lithiums last roughly 1.5 to 2x longer than NiMHs or alkalines. > Life (charge/recharge cycles). Recharge cycles are never as many as claimed. Most NiMH claim 1000 or so cycles, but I've found that the practical life of high quality NiMHs is only about 125 cycles (defined as being able to hold a charge overnight, and operate my mp3 player for at least 4 hours). Only time will tell how many useful recharge cycles are in the lithiums. > Shelf Life (i.e., how long a charged battery holds a charge). NiMH loose self-discharge over a matter of weeks, months at most; standard non-rechargeable alkalines may last a year or two. Lithium batteries claim to hold a charge for 5 to 10 years (the longer times for non-rechargeable lithiums). So, non-rechargeable lithium batteries are nominally ideal for equipment which is likely to remain unused for years (such as emergency equipment) or low drainage items (e.g. smoke alarms, motion alarms). Why not rechargeable lithiums for such equipment? Do you really want to invest in $7 each for rechargeable lithiums? when you can get non-rechargeable lithiums for $1.50 each? But, beware that shelf-life is in unopened packages, not necessarily when installed in equipment. On many modern electronics (even battery-powered electronics) "off" is not truly "off", but rather, is "standby" -- still draining some power. I find it very suspicious how often my MP3 player was operating well at midnight, when I turned it off, but is completely dead in the morning. > Rechargeable lithiums cost $7 each with a dedicated charger, compared $2 each for rechargeable NiMH. But, in equipment which doesn’t work well with NiMH batteries, your only practical alternative is non-rechargeable alkalines at about $0.50 each. > SHORTCOMING: Since the voltage remains at 1.5v until nearly the moment of complete exhaustion, most battery meters will report “full battery” until moments before the battery is completely drained. If low battery warning is important to you, use NiMH batteries, or investigate other brands of lithium batteries, which are designed to progressively lower voltage as the charge is used. MY USE > Purchased for my mp3 player, which malfunctions when the voltage of rechargeable NiMH batteries drops much below 1 volt. So far, no malfunctions with my mp3 player when using rechargeable lithium batteries. > Will purchase more for my TV remote controls, which simply will not work with NiMH for more than 1/2 hour. LIGHTS — The three different sets of indicator lights are confusing — but all that matters is the square LEDs above each battery. > Single Round LED: Green = charger receiving current. > Square LED above each battery: Red=battery charging; Green=charged > Light on top of batteries: Blue=battery charging; no light if charged or not charging. POWER SOURCE — The charger does not come with a USB adapter. To get the 1 hour charging times claimed, your USB adapter (or port) needs to produce 5v at 2 amps. There is a good chance that the old USB adapter in the bottom of your electronics drawer produces only 0.5a --- you still get reasonably fast charging, but not as fast as with a 2a adapter. A “convenient” multi-USB adapter may not produce the nominal amperage if more than one device is plugged into it — so, for fastest charging, I suggest a single-plug 2amp USB adapter, that you label for use with your battery charger, and use only for that purpose. CAUTION — Lithium batteries are inherently 3.7 volts, and until recently 1.5v rechargeable lithium batteries were not available. Internal circuitry in the 1.5 volt lithiums steps down the voltage from 3.7v to 1.5v. Most 3.7v rechargeable lithium batteries are odd sizes to avoid confusion with standard AAA and AA batteries. > In fact, I have 3.7v rechargeable lithium batteries, and a dedicated charger that I use for a (great) flashlight. My 3.7v rechargeable lithiums are an odd size (a little larger than an AA)—but would physically fit in a spring-adjusting charger meant for 1.5v C-size batteries (but would not charge properly). > Conversely, my spring-adjusting charger meant for 3.7v lithiums will (physically) accommodate AA and AAA size batteries . But 3.7v and 1.5v batteries and chargers are not cross- compatible. > There are similarly at least three different competing designs of lithium 1.5v AA and AAA batteries available at this time, which may not be cross-compatible. The simplest solution is to pick a brand of 1.5 volt lithium batteries, and purchase your batteries and charger of the same brand—typically the charger with 4 batteries is only $3–$5 more than the cost of the 4 batteries. Buy the batteries as a package with the dedicated charger. Caveat—the most common battery design (which are sold with identical chargers), are probably cross-compatible. COMPLAINTS OF OTHER REVIEWERS > Yes, sometimes batteries die early. It’s happened to me many times with NiCds and NiMH. There is more that can go wrong with 1.5v lithiums, because each one has its own built-in computer. So the rate of defective 1.5v lithiums is probably higher than other rechargeables. So, test your batteries when you get them, and return any to Amz that fail. Trying to charge the 1.5v lithiums in an incompatible charger might burn out the tiny computer in the batteries. > Otherwise reading the negative reviews, I have the impression that most problems users are having is caused by improper charging --- mostly using battery chargers not meant for 1.5v AAA or AA lithium batteries. — I suspect than many purchasers bought the batteries only, and attempted to charge them in NiCd or NiMH battery chargers. Indeed I was tempted to do so, since I have an expensive NiCd/NiMH charger, and it would seem that "1.5v is 1.5v" and the batteries/chargers should be cross-compatible. But, both the sellers and review articles claim that the batteries/chargers NOT cross-compatible. Solution, shell out the extra $3–$5 for the same brand and model charger when you purchase the batteries — cheap insurance. Why are the NiMH and 1.5 Lithium battery chargers incompatible? Presumably because the brains of "smart" NiMH chargers are built into the chargers. The "brains" of 1.5v rechargeable lithium battery chargers are built into the individual batteries. Practically speaking, my bet is that the "1.5 Lithium battery chargers" are really just "battery holders", and are essentially empty shells inside, and are incapable of fast-charging "dumb" NiMH batteries. — I suspect that some folks (like me) who have chargers designed for 3.7 lithium batteries may say to themselves “Hey, I already have a lithium battery charger — I don’t need to buy another lithium battery charger”. 1.5v and 3.7v batteries/chargers are not cross-compatible. 3.7v rechargeable lithium batteries are not "smart". Most likely a charger meant for 3.7v batteries would burn out the tiny computer of a 1.5v lithium battery. — One person complained that he/she/them could not charge the 1.5v lithiums with a solar charger (of course not, it wasn't meant to charge lithium batteries). Another person could not charge the batteries from another battery "booster" device. Who knows what voltage/amperage those power sources deliver?

These batteries are almost perfect. They are lithium ion, not Ni-cad, which means that they will hold a charge longer and last longer than Ni-cad rechargeables. Also, they charge faster than Ni-cads. These batteries go from zero to fully charged in about an hour. Ni-cads take several hours. And, they are really affordable. I paid $55.88 for eight AAAs, which I can use almost indefinitely. Compare that to Ni-cad rechargeables, or alkaline batteries that are good for one use. The only (slight) downside is that they come uncharged, so you have to charge them before you can use them, and, you have to know when they are fully charged. When you put them in the charger a blue light shows at the + end of the batteries, with a red bar above each battery on the charger. I found this confusing. On all of my other rechargeables , blue indicates fully charged. Here it doesn't. Here, fully charged is indicated by the red bar on the charger turning GREEN, as in "GO." Minor annoyance for charging the first time. I look forward to using these batteries for a long time and am planning to buy more.

Hold decent charge

I thought that I loved these lithium AAA batteries, but after three cycles of charging and use, one out of the four batteries is dead and is not recognized by the charger and reads 0 volts on a voltmeter.

Bought these to use with my Meta Quest 3 headset. They work great and they do charge fast.

I compared the charging time between this unit and an EBL. The EBL is 28% faster using same batteries, cables, USB Block and outlet.

Lasts so much longer that I lost both of my Kratax chargers.

It is very good for my vox amplug - electric bass guitar.

These batteries are so awesome. I now have a small collection of these for all my constantly used battery operated electronics, like my front door dead bolt and doorbell camera. I actually have 2 sets and swap them out very quickly. I highly recommend these batteries. FYI, I have been using these batteries for several months now and I haven't had any issues or failures and I have put quite a few cycles on several of these batteries.

Very good batteries no complaints here

la qualité semble bonne !

These batteries are a bit pricey, I hope that they will perform well in long term. There are so many brands with different prices available. I like this type of AA and AAA cells, at 1.5v and holding their charge for a long time, much better than 1.2v NiMh cells. These batteries come only with its own 4 cells charger and an usb-c cable, but you need a USB wall charger 5v-2A . There are also other brands batteries on the market that can be charged individually with an USB-C cable.

Tel que décrit.