Panasonic Eneloop

Eneloops are fantastic. I've been using them for 10 years. They have very low self discharge so you can keep them on the shelf for a year and they will still have 70% charge which is very different to most rechargeable batteries. They don't leak unlike alkaline batteries and you can run them to 0% charge without damaging them unlike Lion batteries. The terminal voltage is only 1.2v so there is the occasional thing they don't work well in. That said my collection of eneloops get much less use than they used to as everything comes with built in lithium batteries and a usb charger nowadays. That is very convenient until the moment the lithium battery dies... Changing the lithium battery in things sucks. Firstly it's really difficult to get a good one and not a crappy knock off. Secondly modern stuff isn't meant to be repaired. Every time I pick up my kindle I shed a small tear when I see the screen damage I caused changing the battery. So, I buy stuff with AA or AAA batteries if possible and if I want it to last for more than 3 years.

Here are some rechargeable AA batteries that were specifically tested and worked in toothbrushes [1]. For almost all devices there is no good reason to care that the nominal voltage of NiMH rechargeable batteries 0.2V lower than the nominal voltage of alkaline non-rechargeable batteries. Alkaline batteries have a steeper initial discharge curve and pretty quickly drop below 1.3V. If your device has trouble with 1.3V it is either going to almost instantly stop working if it is a high load device, stop working after using maybe 10% of the battery's capacity of it is medium load, and maybe 30% for a light load. On the lasting a decade or more front, I'm still using 19 of the 24 1st generation Eneloops I bought sometime before March. 2 died and 3 are missing. Last time I went through and measured their capacities, about 3 years ago, they averaged 1886 mAh. They were sold as having an average 2000 mAh capacity with a minimum of 1900 mAh. I've also got 15 4th generation Eneloops bought 2014-08. Those are also all still fine, with an average capacity of 1960 mAh. You might wonder why I bought the 4th generation ones since the 1st were still fine. It is because they greatly improved the self-discharge. 1st generation was specced at retaining 80% charge after a year. 4th generation is specced at retaining 90/80/75/70 after 1/3/5/10 years. I've got some lower power applications where changing batteries is annoying, so I want to minimize self-discharge. [1] https://www.nytimes.com/wire…

I've never had a problem with the basic 4-cell chargers that Panasonic includes with their Eneloop starter kits, other than the mildly annoying fact that they cover more than a single plug on a power strip. Build quality seems fine, and I've been using them for decades without a single failure, so I've never seen any reason to even investigate alternatives.

The overall recommendation for an AA battery comes at 7:30. It's the only one I buy, the white Panasonic eneloop.