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Comment by dragontamer | Hacker News Reader

I think the main issue with AA Alkaline is the proliferation of cheap low-self-discharge NiMH cells (aka: Eneloop, but also Energizer and other brands have good LSD NiMH available).

A huge number of appliances seem to be designed for the 1.35V NiMH chemistry now. Perhaps a random TV-remote still prefers Alkaline but most seem to work fine with NiMH.

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Buying a pack of 20 NiMH cells and rotating your collection between charging / discharging states is cheap enough and effective. Its like you have "infinite" AAs since you can just keep recharging them.

EDIT: A few years ago, Alkaline was still needed for TV remotes. But most Low-self-discharge NiMH now lasts for over a year without self-discharging away. Sure, not as good as Alkaline's 10-year life span but surely 1+ year lifespans is good enough for your TV remote? Its not that big of a hassle to reach recharge your NiMH once a year is it?

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That works well until you have kids running around... You going to put rechargeable cells in that Elena of Avalor wand your 4 year old chases the dog with? And her talking unicorn? How about all the light sabers?

In my experience, most of those types of toys don't go through batteries fast enough to justify a NiMH - they'd be in there for years. Invariably one of the kids will wind up mixing NiMH/LiIon/Alkaline in a toy, then the rechargeable winds up in the recycling bin a year later.

Fast forward 3 years, and your "infinite" AAs are all gone, lost, or in near-permanent use somewhere you can never identify, and you've wasted all that money.

In a few years when the kids move out and, and the number of battery powered gizmos is down to a manageable number, I'll try it again - until then, Amazon Basics AAA/AA are my friend.

I do this with my child. Shrug, I just buy more amazon rechargables and while it feels expensive its still a fraction of what buying non-rechargables cost over time.

The only exception is his collection of lightsabres. Its like 3 AAA per and he and he has 6 or 7 of them, maybe more. So for those I bought a pack of alkalines and forgot about them. I needed batteries and just bought them from CVS because I was in a hurry.

Amazon lists the EBL 20 pack of AAA batteries for $22. This is about $8 more than the alkaline pack I bought. Now I regret not just spending a little extra for rechargables because those alkalines will drain and leak sooner than later. Or the lightsabre will break then the batteries can go back into rotation.

> I just buy more amazon rechargables and while it feels expensive its still a fraction of what buying non-rechargables cost over time.

Putting rechargeable batteries in a toy that will likely not need a replacement for a year or more definitely feels like a waste of money - as does knowing that 20+ rechargeable batteries have been thrown out with regular batteries and broken toys.

Unless I know I can get 8-10 uses out of them, it doesn’t seem ecologically or economically prudent to use rechargeables.

edit . Also - child != children. We have well over 100 AA and probably as many AAA batteries in various toys at any given time…

Replying to boost this. We love Eneloop and have probably 40-50 of them in the house at this point, between remote controls, gamepads, children's toys, fairy lights, bike lighting, tools, etc etc. They all get funneled through a La Crosse charger with a simple two-bin depleted/charged system.

We've been buying them for years and I think I've only ever disposed of one that was unwilling to take a charge.

I agree, rotating collection of charged cells is the way to go but:

- need to establish a system of keeping track what's charged

- train family to participate

- train family to stop buying alkaline (mainly because in the alkaline recycling process you'll lose a lot of your eneloops)

- grow immunity against complaints from family

> - need to establish a system of keeping track what's charged

This seems to be the root of all of your problems.

Just charge all of the cells that aren’t in use.

When you take drained cells out of something, they go in the charger.

Charger is always plugged in and right next to where you store the cells.

If there’s ever any question, just stick the cells in the charger. Don’t bother playing all of the games to avoid “memory effect”. It’s much better with modern cells and not worth the hassle to try to work around.

The good chargers hold 8-16 batteries, so there's always a set on there being charged. The chargers seem electrically smart and maintain the batteries well.

This process works wonderfully. We've got ~100 Enloop's of various generations around the house in TV Remotes, XBox Remotes, Garage Door openers, and toys. This process works well.

Not to mention a LOT of items now come with non-removable (mostly rechargeable) Li-Ion or NIMH batteries. Even small toys which used to require external batteries now come with it.

So I still have a small stack of alkaline batteries from 2017 I haven't replaced or depleted. Hopefully that stack remains untouched for another few years as well.

Just want to signal-boost Markus Wandel's Ni-MH battery tester/matcher on Github: https://github.com/MarkusWandel/battery-tester

I'm (lackadaisically) building a version of it now, in order to get matched pairs and fours of the 40-plus eneloops that we have. And identify the bad ones, of course.

> A huge number of appliances seem to be designed for the 1.35V NiMH chemistry now.

Yes, this is my experience too. One of the problems with NiMH is that appliances have helpful low-battery indicators which might light up as soon as you put NiMH cells in them, even though the appliance might continue working for a long time yet. A prime example is the Nintendo Game Boy Advance, which was released in 2001. The thing is powered by switching regulators which work fine with the lower voltages of NiMH cells!

Newer appliances have solved these problems. For example, the Yamaha PSS-A50 (a fantastic, inexpensive portable keyboard) has an option to configure the low-battery indicator for alkaline or NiMH chemistry.

Totally agree! My Game Boy Advanced power light is green for about an hour then red for hours and hours on my eneloops. Also my Tascam field recorder has the option for alkaline or NiMH batteries.

I still have some kitchen scales that won’t work with NiMH though :(

I’ve had my energiser batteries for almost 10 years and I’ve been rotating them through devices and the charger. Only recently have I begun to lose some cells.

Time to upgrade them all to eneloops!!

Honestly, Eneloop's advantage is overstated these days.

Amazon Basics is likely an older Eneloop design for example (Panasonic makes eneloop, and seems to be making Amazon-Basic NiMHs). Energizer's "AA Recharge" series is also LSD these days, and probably easier to source than Eneloop.

Eneloop deserves credit for shifting the market-perception on NiMHs a decade ago. But the other companies have caught on and have created well functioning, low-self-discharge chemistries of their own by now.

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I'd recommend "whatever is cheapest to ship to you". Energizer mostly for me, since I buy from Walmart / Home Depot (etc. etc.). A lot of people buy from Amazon, so "Amazon Basics" tacked onto your next order is probably a good idea.

Eneloop commands a higher price and has some advantages. But I find that Energizer / Amazon Basics are both good enough for me.

A quick googling reveals nothing, but I wonder if a simple hardware mod could address this— basically, identify the voltage divider that's doing the measurement across the battery and change out one of the resistors so that it "sees" 1.35V as 1.5V.

Most GBA battery mod posts are about people upgrading units to have built-in lithium packs, USB-C charge ports, etc etc.

Nope.

Alkaline at 100% charge is 1.5V, at 50% charge it's 1.2V, at 0% charge it's .9V.

NiMH at 100% charge is 1.35V, at 50% charge it's 1.35V, at 0% charge it's like 1.2V

Totally different discharge curves. There's no simple circuit to convert between the two.

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EDIT: For hard data, see:

Energizer NiMH : https://data.energizer.com/pdfs/nh15-2300gl1220.pdf

Energizer Alkaline: https://data.energizer.com/pdfs/e91gl0320.pdf

Oh yeah, I'm aware that for any other chemistry you need an actual coulomb-counter to get a proper gas gauge. My suggestion was more about the specific matter of suppressing an unwanted and inaccurate low battery light.

Though maybe instead of trying to mod the circuit board, it would be easier to just disconnect the LED itself.

Or just to ignore it.

Haha try as I might, my child brain still panics when I see that red LED and I end up saving more often because of it haha

Haha, PTSD from the Gameboy suddenly dying on you isn't easy to shake :P

Thankfully my not so new handheld Garmin GPS unit has a specific NiMH battery mode. I'm sure it just changes the algorthm slightly to work with the NiMH's discharge rate.

> Newer appliances have solved these problems. For example, the Yamaha PSS-A50 (a fantastic, inexpensive portable keyboard) has an option to configure the low-battery indicator for alkaline or NiMH chemistry.

Different NiMH chemistries have slightly different voltage curves.

Its an insidious problem. Different brands of NiMH just discharges in a "flat" manner, and all of them are at slightly different voltages. The electronics assume a voltage curve of Eneloop (typically, since Eneloop is the most popular NiMH brand), and other brands with their slightly different voltage-curves will throw it off.

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I find it more important to locally source NiMH batteries (ie: what I can buy from Walmart / Home Depo down the street, rather than paying for Amazon shipping) rather than standardizing upon the Eneloops that everyone else is buying, lol.

When I need a new AA cell, I buy it in my typical shopping runs, rather than waiting for shipping. I don't care enough about the voltage-curve problem to mass buy Eneloops yet. I largely just accept that the "low-battery" indicators are perpetually wrong.

One interesting solution I saw was batteries which stick a lithium battery + charge controller / voltage adapter inside the AA package so they can be used on any device.

I had some old (built in the 80s?) handheld radios that included a dummy battery for when you were using alkalines, and you'd populate all the positions with real batteries if you were using rechargables. I think it was something unusual like 8 batteries in series.

I've switched to rechargables for home electronics years ago. It makes me feel better doing my share of lessening environment impact caused by disposable cells.

One notable exception for which I am still buying alkaine batteries is the August Smart Lock. When using NiMH batteries it starts complaining about depleted battery in a week, while it still Ok and works for much longer. It was reported to them and they advised to us alkaine. This is very annoying because all they need to do is to fix the software which does the voltage check and generates annoying notifications to the users. Just a few lines of code (or maybe single constant) could have an immence environment impact.

I think this explains the problem, though If you could configure the battery type, a software fix would work:

https://news.ycombinator.com/item?id=29910710#29912483

that's exactly the problem. there is no option to configure battery type.

I finally switched to Duracell’s rechargeable NiMH batteries last year and won’t be going back to alkaline. They work well even for things like flashlights that need low self-discharge, and I no longer feel like I’m creating waste every time I burn through a battery.

I also came across some rechargeable lithium batteries packaged in 1.5V AAA, AA, C, D form factors, but they appeared to be newer and I was unsure about long-term reliability.

The only thing I keep disposable batteries for is my key code door lock

I probably have around 100 NiMH AA batteries at home, around 30 AAA ones, most of them are Eneloops, around 20 are Energizers and around a dozen are some misc. brands. Most of them time they are good but still a couple of Eneloops died just around 5 years. Moderate leaks but did not cause any trouble. Seemed to be caused by the fact I left them in toys and let them run flat for fairly long time(not sure how long, but should be less than a year). In the same period, I threw away double the amount of other brands ones. Most of the rechargeable ones are still going strong. I do observe a few of them are pretty weak and most likely going to die in a couple of months. In general, the cost to use rechargeable ones are only 1/4 to 1/3 of alkaline ones.

The only things is that some of the appliances does not like NiHM batteries. I'm no saying NiMHs do not work at all but rather they stop working with around 75% charge left, which is quite annoying. I use alkalines with them if I observe such behaviors.

I design some electronics in my spare time. As a user, I strongly prefer to have a choice of using a rechargeable battery. It somehow does not feel right to throw out a toxic battery when I could have another type potentially hundreds of times over many years.

It helps that there is a proliferation of quite powerful, low voltage, low power chips.

Some of the devices I design have USB interface which gives another option of charging the battery while it is connected.

I am currently working on a fully programmable mechanical USB/Bluetooth keyboard. It will work off of two AA NiMh rechargeable batteries and I plan these to be recharged any time the keyboard is connected to the computer.

I'd assume that 3-cells could lead to a simple trickle-charge circuit?

3*1.35 == 4.05V, which is pretty close to the 5V power that you take from the USB, seems like there's enough room to get a regulator to turn 5V into a simple charging circuit. There'd also be enough output to probably run 3.3V circuits with a simple regulator.

4*1.35 == 5.4V, which is beyond the capacity for 5V to charge (unless you got a boost-converter).

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2-cells == 2.7V, which means you probably need a boost-converter to convert the battery-pack into something useful?

Not that I'm the designer or anything, but I like discussing these issues :-) I haven't done any electronics since my college days.

What voltage does the device operate at? The main cutoffs these days seem to be 1.8V, 3.3V, and 5V right? 3-cells and targeting 3.3V + charging from a USB (at 5V) seems like the most obvious cutoff to me personally.

Newer STM32 lines go as far down as 1.7V. Or they would if I was able to find other chips (notably Bluetooth) that would suit me and could pull the same trick. As it stands, the circuit can work down to ~1.85V which is still quite comfortable with two cells.

I admit there is no particular reason to use 2 cells where I could use 3 (they would still fit comfortably inside keyboard enclosure). The only reason is vanity -- I hope it will look sexier to other EEs:)

I dislike built in cells. I like ability to just change batteries rather than have to plug in to charge. Nothing worse than a peripheral like headphones that you have to stop using just because charge ran out. Why do I need to finish my couch session just because my keyboard can't take a simple AA battery or two? Seems like completely unnecessary nuisance.

Also, if you are talking about cell voltage, you need to remember they loose voltage very quickly upon discharging and most of the discharging happens at much lower than max voltage. For NiMh you really want to make sure that your circuit works with at least 1.2V per cell (as an absolute minimum, in perfect conditions of room temperature and very low discharge). Any higher than that and you aren't actually discharging the cells properly and are not using their capacity.

If your circuit works in short bursts of high current or can be used outdoors, be prepared that the voltage can drop very quickly especially when the cell is older (has been through a lot of cycles).

How do you find good cheap low-self-discarge NiMH cells? I couldn't find any research on them (like the post article but for NiMH) because of SEO spam, and Amazon reviews are (of course) worthless.

Heck, I'm afraid to even buy NiMH batteries because of counterfeits. I bought a few batches of Amazon Basics batteries a year ago and 3/8 are dead already, but even if I purchased something labeled "Eneloop" on there, how do I know it's Eneloop?

Most of my remotes are still using the batteries they shipped with. It's hard to make the case for replacing batteries when the originals last 15+ years (and counting).

A youtuber I watch recently made the case that NiMH batteries should be used for _all_ uses because alkaline batteries will eventually burst and spew acid over your electronics. Sounds like it could take a very long time to do that, but it makes sense just for the preservation of the device to use NiMH.

Anecdotically, yet a few of my remotes after a decade of use on original batteries suddenly got less and less responsive. Change the batteries! Right?

Well, turned out the original batteries were still alive, but on a closer (painful to nails) inspection, it turned out that the silicon buttons/pad started leaching the oily goo onto the contacts on the PCB thus reducing the responsiveness.

Swabbing and washing restored these, but something tells me this problem will be back sooner than in another decade.

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