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Ode to the AA Battery

jeffgeerling.com

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Re: Ode to the AA Battery

#51

Post by ghaff »

zabzonk wrote: post #22
jchw wrote: post #7

Earlier quoted context omitted.

I believe I have zero Alkaline batteries left in my house and I'm relatively surprised that pretty much everything works fine. If anything, I suspect the only problem is that some devices have an inaccurate account of how dead the batteries are. But I use Eneloops on everything, even things surely not designed at all to run on them. (And I reckon you could probably make more devices work if you really wanted to; addi…

I think I have only one device that uses AA - my central heating's radio thermostat. This thing has caused me untold hassle, which is only partially down to the batteries, but still... Totally OT, but does anyone have a good link on how the thermostat gets paired with the boiler? I'm thinking of getting replaced and would like to talk to the gas fitter from a vaguely informed point of view.

Personally, I keep things simple. Got a new (pretty basic) Honeywell thermostat after a kitchen fire; thermostat was pretty old anyway. For wiring, you mostly have 2-wire and 3-wire although there are a lot of variations as you get fancier: https://nassaunationalcable.com/blogs/blog/a-full-guide-to-t...

Number of zones in the house may affect things as may boiler only or AC being in the picture as well.

Re: Ode to the AA Battery

#52

Post by Zak »

jonpurdy wrote: post #27
dragontamer wrote: post #9

Earlier quoted context omitted.

That's not the reason. Alkaline batteries only have 1.5V for a short time. In practice, toys are designed to opeerate off of 1V to 1.5V, because Alkalines vary _wildly_ in voltage during use. NiMH at 1.2V _STAYS_ at 1.2V, even when drawing 1Amp or more (under these conditions, Alkaline would have long dropped below 1V). EDIT: This is also a problem because "nicer toys" will measure the voltage assuming an Alkaline is…

I had an issue with the original Apple Magic Mouse that would not work correctly with NiMH batteries but work fine with disposable AA. The mouse would be fine for a few days then randomly stop working; using fresh NiMH would revive it again. I assumed it was due to 1.2v vs 1.5v but perhaps that particular mouse (or all Magic Mice) was just bad.

Looking at the discharge curve for an alkaline, much of the energy is below 1.2V even under light load. A device that works with alkaline and not NiMH due to voltage is broken as designed.

https://lygte-info.dk/review/batteries2012/Duracell%20Ultra%...

Re: Ode to the AA Battery

#53

Post by randusername »

My offshoot rant is that it should be easier hold devices at a longevity charge.

I want some gadget that keeps my essential gear in a long-term maintenance mode. Oscillate it 20-80% or keep it at 50%, whatever is optimal.

Every time I've looked into building something like this it seems like there's no standard reporting of charge level over the wire. I would waste a genie wish on this to have it in the USB spec and widely adopted.

Re: Ode to the AA Battery

#54

Post by Zak »

MarkusWandel wrote: post #15

Am I courting disaster by reviving won't-charge pouch cells by just manually running a bit of current through them until they're nonzero volts and then a normal charger will do the rest? So far, in the maybe half dozen times I've tried it (rectangular battery blocks for old digital cameras, the pouch cell inside a long-disused Kobo Reader) it's worked. They charge right up, they don't swell, and they still have decen…

Over-discharged Li-ion cells can grow metallic lithium dendrites that result in internal short circuits. Charging them again following over-discharge does create a risk of fire/explosion.

Re: Ode to the AA Battery

#55

Post by ahartmetz »

Lutzb wrote: post #8

The best thing about Eneloops do not seem to leak. I can just leave them in rarely used electronic devices without worrying. They might discharge, but so far this has never been a problem.

I don't think that I've ever seen any NiMH leak. If you look at teardowns - it's maybe not even possible. They look rather dry inside.

Re: Ode to the AA Battery

#56

Post by bxparks »

jchw wrote: post #7
klooney wrote: post #2

> run at a nominal 1.2V instead of the 1.5V of alkaline batteries. I've suddenly figured out why so many toys don't work with rechargeable batteries

I believe I have zero Alkaline batteries left in my house and I'm relatively surprised that pretty much everything works fine. If anything, I suspect the only problem is that some devices have an inaccurate account of how dead the batteries are. But I use Eneloops on everything, even things surely not designed at all to run on them. (And I reckon you could probably make more devices work if you really wanted to; addi…

Three things prevent me from eliminating all alkalines:

* smoke and CO detectors with low-battery voltage sensors calibrated to alkaline

* some older electronics (e.g. multimeters) using 9V batteries

* my non-contact voltage tester refuses to turn on using NiMH, for safety reasons presumably

Re: Ode to the AA Battery

#57

Post by ahartmetz »

Zak wrote: post #52
jonpurdy wrote: post #27

Earlier quoted context omitted.

I had an issue with the original Apple Magic Mouse that would not work correctly with NiMH batteries but work fine with disposable AA. The mouse would be fine for a few days then randomly stop working; using fresh NiMH would revive it again. I assumed it was due to 1.2v vs 1.5v but perhaps that particular mouse (or all Magic Mice) was just bad.

Looking at the discharge curve for an alkaline, much of the energy is below 1.2V even under light load. A device that works with alkaline and not NiMH due to voltage is broken as designed. https://lygte-info.dk/review/batteries2012/Duracell%20Ultra%...

If you need 1.5V / 3V for some reason, you could maybe insert a tiny boost converter from AliExpress (1€, less than 1 cm in all dimensions). I have done that for a string of fairy lights.

Re: Ode to the AA Battery

#58

Post by vladak »

creaturemachine wrote: post #23
MarkusWandel wrote: post #15

Am I courting disaster by reviving won't-charge pouch cells by just manually running a bit of current through them until they're nonzero volts and then a normal charger will do the rest? So far, in the maybe half dozen times I've tried it (rectangular battery blocks for old digital cameras, the pouch cell inside a long-disused Kobo Reader) it's worked. They charge right up, they don't swell, and they still have decen…

I've jump-started my share of batteries this way. Such a deep discharge might affect lifespan but it's typically old devices we do this to anyway.

Cool. I have a modern (not smart) body weight scale and it regularly ruins this way at least one of the 3 GP NiMh rechargable AAA batteries I put in it, so I wanted to hear some ideas what could be done with them given they have been through only bunch of charge cycles.

Re: Ode to the AA Battery

#59

Post by Zak »

voidUpdate wrote: post #21

Whats the energy/volume comparison between standard AA batteries and li-ion batteries?

Highly variable based on load and the specific batteries involved. Alkaline will almost always have more capacity for something that takes more than a day of continuous operation to drain the battery, and NiMH will almost always have more for something that takes less than four hours.

Here's a tool you can use to compare different batteries at different loads, graphing voltage vs Amp-hours. The individual battery tests have more detail and graphs of voltage vs Watt-hours, which is often a more useful measurement.

https://lygte-info.dk/review/batteries2012/CommonAAcomparato...

Re: Ode to the AA Battery

#60

Post by jasomill »

alnwlsn wrote: post #30
amelius wrote: post #4

Speaking of which, I really hate those chargers that force you to use two batteries instead of one. I get that it is cheaper to design it that way, but come on.

Speaking of which, I have yet to see a consumer battery charger that isn't incredibly cheap feeling. Even ones for charging different chemistries or that let you set current rates are a mess of low-quality molding and cryptic button presses.

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.

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