[danaris]

I would agree if I could buy a AA battery that would power my toothbrush for a year. Or one that could be rechargeable with easily-available chargers reliably for a decade (and without having to drop 0.2V to achieve it...).

Any kind of consumer power technology can only ever be truly "good enough" if it never causes any inconvenience or significant cost.

[tzs]

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/wirecutter/reviews/best-rechargeable...

[danaris]

> 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.

The few times I've measured the voltage of my non-rechargeable AA batteries (which, granted, was infrequently, and not recently), I haven't seen them drop below 1.3V until they've been in use a while.

And I've much more reliably observed that when I try to use rechargeables in my electric toothbrushes (Oral-B Pro Clean, the kind with separately moving round and long brush sections, which are, alas, no longer available anywhere I've been able to find), they start out very sluggish, and gradually descend to near-uselessness, while using non-rechargeables makes the toothbrush very energetic at the start, declining fairly steadily over a month or three, with it matching the level of the rechargeable at something like 2/3 of the way down.

I'll take a look at the Wirecutter link; thanks!

[BobaFloutist]

> Any kind of consumer power technology can only ever be truly "good enough" if it never causes any inconvenience or significant cost.

I mean, that's not the case with current consumer power technology