Powerex PRO High Capacity Rechargeable AA NiMH Batteries (1.2V, 2700mAh) - 8-Pack

They've been re-charged more times than I remember without an issue. They do not noticeably lose their charge or leak while not in use for extended periods of time. I'm very pleased with them.

I have been a longtime user of these batteries and found they last longer and keep their charge longer than others.I don’t think you will be disappointed purchasing these batteries.

The TL;DR is that I'm happy enough with the batteries that, as the rest of my other batteries come due for replacement I'm planning to switch all 30 of them to these.I've been using rechargeable AAs pretty consistently since the early 2000s. It started off mostly being for my camera flashes, but I've been using them in a lot more stuff over the years as the battery tech has improved and as I started using more battery powered stuff. But, in all that time, buying this 8 pack of Powerex Pro batteries several months ago is my first experience with the brand.For the past 15-ish years, I've predominantly stuck with using Eneloop batteries (the regular ones, not the Pro) and they've been OK for me, but now that I'm using the batteries in more devices with motors, they're just not cutting it. The Eneloops will barely spin up some of the motors when they're under load, even when they're fresh off the charger, while these Powerex batteries keep the motors working as hard as they're supposed to. And, for things like my camera flashes, while the Eneloop batteries have been OK, they've never been great because they take longer to charge the capacitors. These Powerex batteries do better there too.Battery runtime is good. As long as stuff runs long enough, which I recognize is a subjective thing, I don't really care about the specific time, so I haven't done a real comparison test. These definitely run long enough compared with all my other batteries that I'd say they're at least as good as anything I've had previously, probably better.Service life will probably be fine, but I haven't had them long enough to comment on that. But, I will say that, if you're concerned about service life, use a high-quality, slower charger. I've been using an Ansmann Energy 16 charger for about 18 years as I'm writing this and when I switched to that charger my batteries began lasting several years longer before needing replacement compared with using a rapid charger. The quality of the batteries is only one part of what determines the service life. I also pull my batteries early if I'm using them in a high-drain situation so that the heat doesn't get a change to affect their longevity as much.I don't think they're being completely honest with setting expectations for the self-discharge rate, which is to say that I don't think that, if I left the batteries sit unused for a year after being taken off the charger, they'd still be at 75%. I haven't done any formal testing to prove the numbers, but I haven't been using the batteries as much as normal this spring and after some were sitting unused for probably about 3 months, my Xbox controller indicated much lower state of charge compared with a set taken straight off the charger and my charger indicated they were below 80%. Normally, I don't let batteries sit without being used for more than a couple of weeks after taking them off the charger, often no more than a couple of days, so it's a metric that doesn't really matter to me, but it's still worth mentioning.

The tests of this, and other NiMh, on the market - indicate easily that these are best-in-class; So, I have been using the Powerex and the Imedion battery with MaHa charger for ten years now; I have discarded a few that fail to test and charge properly after a few years - and that makes the MaHa charger extremely important (it will indicate when a battery can no longer be used reliably);Cycling NiMh such as these regularly is important;And, charge them immediately before you plan to use them;Use the Imedion battery in applications where it may sit un-used for up to twelve months;Use the POWEREX in a daily or weekly-use items such as a camera flash; these are great in a camera flash such as SB600 (fairly large flash);And, the MaHa product line has many other choices; and the MaHa charger can be used on Panasonic Eneloop and any other NiMh battery.Powerex is simply the very best in mAh and long-term reliabiliy (from a ten-year user).These batteries are a very good investment, be sure to get a MaHa charger with them.The first thing you will do with your MaHa is to weed out all of your bad / weak NiMh batteries from you battery drawer and properly re-cycle them; getting rid of the 'weak link' batteries is half the battle; if you have four NiMh ina camera flash, and one of them is weak, it is the same as if all four are bad / weak, because the batteries are wired in series. If you have a suspect battery: discard it (recycle)!Also, MaHa charger can be used to sort and group batteries by their capacity; so you can choose your four very best batteries, for example, for your most critical application; I will sometimes group batteries for my camera flash or for my flashlight, as one example. MaHa also sells a D battery with an insane mAhr rating say for a Maglite or similar critical use;

I like this brand of battery, but I have noticed that these higher output batteries do not have as long a life as the standard output versions, so that being said it comes down to do you need high output or is longer battery life what one is looking for. In this case I have some devices that are really greedy on power and these last longer in them, but again you will only get about 500 charge cycles out of them before they go bad. If you need higher output then these are very good for that type of use and then the only draw back is having to replace them more often. I still get about two to three years out of them, but the standard Panasonic I have 10 years out of them, but they also don't last as long between charge cycles, so you will need to charge them more often. I would recommend these batteries.