I know these are currently out of fashion but I’m still thankful they exist.
Let’s remind ourselves of devices that use(d) these standardized batteries:
- Toys
- Digital cameras
- Torches
- Gadgets like fans
- Wireless keyboards
- TV remotes
Thanks to having a standardized system of batteries,
- You can use the same battery across several devices. This is a no brainer but it’s very practical.
- Batteries can charge quicker thanks to being put in a dedicated charger and not being limited by USB cables. (But yes I concede that USB has been updated for faster charging over the years)
- Devices don’t have down time when their battery is charging. To charge, the battery is removed from the device and can immediately be replaced with a fresh one.
- You’ll never have to trash a device due to an expired battery. Just buy a replacement. And building on this…
- Any improvements in future battery technology can be retro-fitted into your existing devices. And there is a high incentive for future improvement, because…
- An accessible (due to easy replacement) and large (due to many devices) battery market is very attractive to competition.
If you look at the pros I listed, they all happen to be things that would be very useful for electric cars. So I think it would aid the adoption of electric cars if their batteries were standardized too.
Those batteries in your photo are NiMH batteries… which discharge on their own at a fairly rapid rate even if you’re not using them at all. They’re also pretty big and heavy for the amount of power they provide (which, due to the self-discharge issue, is effectively a lot lower than the official number on the battery).
I strongly recommend investing in devices that use 18650 batteries. They’re about the same size/weight as a AA, and they last much longer (both in terms of from full to flat and also the number of years (decades?) of use you’ll get from the battery.
A lot of “proprietary” batteries are in fact a bunch of 18650 cells wired together.
It’s worth investing in good ones - the quality varies significantly from brand to the next. With a good 18650 cell, you won’t be replacing it when the battery expires, you’ll be transferring it to a new gadget when the gadget is broken or so old that you decided to buy a new/better model.
An 18650 is way bigger than a AA
While all this is true, unfortunately not many devices support swappable 18650s, either they have swappable AA/AAA or have built-in 18650s that would require disassembly to replace. However, if you CAN find a device with swappable 18650s (the only ones I’ve found so far are flashlights) they’re absolutely great!
I am not aware of many devices that use swappable 18650’s either. Off the top of my head the only ones i’m aware of are vape devices.
There are also flashlights with 18650s. There are some powerbanks with exchangeable 18650s as well.
But that’s all I know of.
My OWON portable oscilloscope does. The only device I know of.
Wait, do they not make AA-sized 18650 batteries?
18650 isn’t a specific type of battery, but a size. 18mm diameter, 65mm length, and 0 typically represents it being cylindrical in shape. 18+65+0
Besides being the wrong size by definition, AA batteries are expected to have 0.8V to 1.5V, while Lithium Ion cells (such as 18650) have a voltage range of 2V to 4.2V. That’s completely incompatible, you couldn’t even replace two AA batteries with a single Li-Ion cell.
Couldn’t it theoretically be fixed with a voltage regulator?
Don’t they need a circuit protection to not over-discharge lithium batteries? Most AA devices would suck all the juice from the battery until it stops working.
The problem with those is that the device loses the ability to sense the charge status of the battery, since the voltage remains the same until it’s empty.
Yes.
The other problem with lithium batteries like 18650s is that they need to be handled with care so manufacturers don’t want users swapping them in and out like AA/AAA. This is why they build them into devices and have you charge them through a regulated port.
Also there are numerous different versions and sizes of 18650, some come with protection circuit, some don’t, some have flat top, some have button top, and whatever type you end up with might or might not fit your device. Makes the whole situation quite confusing for the average user.
you couldn’t even replace two AA batteries with a single Li-Ion cell.
That can actually work. A single 14500 Li-Ion along with a dummy battery can work in many devices, as they have regulators for the voltage in the device (it might blow up other devices and won’t give any energy advantages). That said, there is very rarely any use for this these days, as you can buy 1.5V AA Li-Ion batteries with the voltage regulator build in, that will work in all devices. More expensive than NiMH however, so only really good when the device absolutely needs the 1.5V and isn’t happy with the 1.2V of NiMH.
Low self discharge NiMH batteries have been available for a long time now. They hold a charge for several years.
@abhibeckert I have those from Eneloop. They do not discharge that fast as the old generation of rechargeable batteries. Yes they do, but the rate is quiet slow.
Same. People used low quality Ni-Mh batteries and got what they paid for. Eneloops have worked great for me. Believe it or not, Duracell has been great too. It’s the energizers that have all been awful for me.
I second that. Have been migrating devices over to eneloop batteries successfully. (other NiMH batteries go flat after a month even if not used.)
Oh I see, I’ll look into them. Yeah these are at least 10yrs old so I wouldn’t be surprised if the technology was quite bad for today’s standards
For example, basically all power tool batteries.
If they advertise ~12V, it usually means it is 3 ‘cells’ of 18650s in series. Crack open the case on such a tool battery and you’ll find just that – 3 18650 batteries for a little one. A high capacity battery might instead of 6, with 3 pairs of 2 parallel batteries, doubling the capacity. And nothing but weight and size stops them from just making them ever-larger.
18-20v tools are 6 cells (18v is the nominal voltage, 20v is the ‘max’ voltage at full charge). For higher cap, add more batteries in parallel in each series cell.
It is RARE to be able to service these unless you have some specialized skills. Typically, they are spot welded together, which can be dangerous to attempt to DIY. That said, often when a battery ‘fails’, it’s actually just one 18650 that has failed and taken the others down with it.
These days you do see other sizes. 21700s or even pouch batteries are starting to be more common when tools need more stored joules per unit volume.
There are some clever innovations from some tool manufacturers too.
DeWalt has launched batteries that work with both 18v and 54v systems, by having different pins on the output wired to different points in the battery chain.(3 sets of 3 in series for 18v, or 9 in parallel for 54v, I’m assuming)
They make USB rechargeable lithium ion batteries in every common form factor. I use lithium rechargeable AAA batteries in my mouse and they work great. You don’t even need a charger, they are USB-C. Highly recommend.
They can be very useful for the devices that want the full 1.5V, as they can provide that 1.5V across their whole charge cycle, unlike NiMH and Alkalines that drop down the voltage. They are also lighter than NiMH. However they are also more expensive and for most devices NiMH will work just as well, while costing less.
Another thing worth mentioning, NiMH show charge in mAh on the package, Li-Ion very often give it at mWh, which makes the Li-Ion look 20% bigger than they are.
Oh I see, I’ll look into them. Yeah these are at least 10yrs old so I wouldn’t be surprised if the technology was quite bad for today’s standards
I had some Molicel (I want to say, P26s) 18650s in regular rotation that lasted only three years. I went through Mooch’s battery reviews ahead of selecting them, purchsed them at Liionwholesale, and they started heating up in my Nitecore one by one after maybe 1,200 full discharge (e-cig) cycles. Meanwhile, I have vape-shop NCRs from 2016 still humming along (though rarely used).
At this point, I’m not really sure what to make of battery reviews. And the economics work fine for three years of consistent use. I just wish that was how they were sold, not like some absurd number you’ll never hit.
I have a bunch of Eneloop batteries and they’re great.
Tipp for people wanting to get into rechargeable AA and AAAs: get IKEA Ladda batteries and their charger. They are cheap and japanese made. Some people argue that they are just relabeled Panasonic eneloops!
Edit: Oh also if you used rechargeable batteries in the past and you remember them sucking that’s probably true. But the battery chemistry is better now and it’s possible that your batteries degraded quickly because of “dumb” chargers. Modern chargers like the gray 4 battery Ikea charger detect how and for how long to charge and thus will not ruin the batteries.
Its unlikely Panasonic eneloops. Project Farm does a great test for all the batteries and the IKEA showed no characteristics to the Panasonics. https://youtu.be/0A1GvQ40j0Q
The two cells tested in that video are different. The Ladda 2450 mAh is equivalent to the black wrapped Eneloop Pro, but the video only tests the standard white Eneloops which have less capacity but a better cycle life rating. This is honestly one of the most disappointing videos I’ve seen from Project Farm, he didn’t test most of what makes a cell better/worse.
Whether or not they are identical cells, from what I’ve read there is only one factory in Japan that makes NiMH cells, so the Eneloops and the Ladda come from the same factory and are therefore likely to be very similar.
Ahhh, I didn’t know that about the Eneloops Pro. Thanks.
LADDA are my go-to as well. I recommended going with the wall charges and not the USB-A charger, since the latter juices them up very slowly (compared to the wall outlet or the storage+charge box).
Thanks for the info! It’s incredible how much the quality of batteries and chargers vary. It’s good to know a cheap easy place to get them
The best part is that these batteries don’t leak and destroy your devices like alkaline batteries.
Thank you for this post.
I actively avoid buying things with a built in battery. Long ago I spend a pretty good amount on a rechargeable Braun electric razor. A few years later I had to throw it away because the battery stopped taking a charge and I had no way to replace it. I had a drill with the same fate. There was plenty of life left in these devices but not in their custom batteries.
I’ve pulled one of those wireless trimmers apart when it quit working. I found a rechargeable AA battery soldered in there.
Exactly! It’s a shame that they’re becoming less common as hardware gets enshittified
I refuse to buy cordless powertools. I know it’s not exactly the same as built-in batteries, but In their short existence, I have already seen proprietary rechargeable batteries become discontinued (My mom wanted to get an extra battery for a handheld vacuum, couldn’t find the battery by itself, so bought what she thought was the same model; nope, they changed the battery design, even though the rest of the new vacuum was the same as the old one)
Cordless power tools are absolutely worth it, if you use them even infrequently, and every single contactor I know uses them. The battery packs are ridiculously priced but they wouldn’t be used so ubiquitously (especially by professionals) if they weren’t worth the drawbacks. Having to string out extension cords for every tool would be a nightmare.
It’s be way harder for me to go back to corded tools. Li-Po tools are incredibly convenient. I’ve been able to buy adapters for dewalt batteries that make them work with all kinds of tools and devices (including an adapter for a Dyson handheld vacuum).
Lightweight, powerful, and the batteries can be swapped (as well as a decent amount of aftermarket batteries and adapters).
The batteries in Braun razors are replaceable. They even sell those. It’s not terribly difficult, but you need basic solder skills.
I still use them for my TV and AC remotes, flashlights and wall clocks.
I never realised that many people don’t need to use it anymore.
People don’t use them? Rechargeables are so easy and alkaline are so expensive! Rechargeables are about the same price now as alkaline but you get to continually recharge them forever! Why aren’t people doing that???
The alkaline batteries have higher energy density, so they can be significantly less annoying on devices that use more power, like flashlights. I don’t understand why anyone would use them for things like remotes or wireless keyboards since the batteries will last a long time either way on low power devices.
why anyone would use them for things like remotes or wireless keyboards
Alkalines leak a lot and they seem to be worse these days than they used to. From personal experience, there is about 1:10 chance you’ll be scrubbing battery contacts after using Alkaline. And if you forget to remove the battery when the device goes into storage, there is about a 100% chance it will be a crusty mess once you look at the device again, it can take years, but it’s pretty much unavoidable.
NiMH don’t leak, or at least much less frequently with much less catastrophic results. Also with modern low-self-discharge ones (Eneloop, Ikea LADDA) they last years, so they are very usable in TV remotes and the like.
There are a couple of rare devices that really want 1.5V to function properly (e.g. WMR Controller), in those cases 1.5V LiPo batteries can make a good rechargable alternative, but they are substantially more expensive than plain NiMH.
My wife gave me a bunch with a charger for Christmas like 2 years back. They’re all still in rotation for controllers around the house!
The downside is the volt is not 1.5volts. Its closer to 1.2volts. This is fine if you’re using 2 batteries for things like the TV remote. But when you’re using things that require more than 4 batteries, then you might get into some weirdness. I have a remote for my DSLR that sends infrared to the softbox. Every 10 shots, it would miss the shot. It turned out to be the batteries. It needed all 6Volts vs 4.8Volts.
Alkaline batteries lose voltage as they drain, so 1.5V is at full charge but it drops down to about 1.2V very quickly and then stays at 1.0V - 1.2V for most of the alkaline battery’s operating life.
NiMH batteries tend to consistently stay at their nominal voltage (1.2V) through their entire charge.
So in other words, if you have devices that really expect exactly 1.5V per battery, they would only work with alkalines at the very top of their charge. Nowadays most non-garbage circuits should be designed to work just fine with anything above 1V per battery.
I have a dozen or so AA (at least 10? 15? years old) and four AAA. They hold a charge very well, and are easy to charge from a solar panel when needed. They’ll top up a phone during a blackout or a camping trip. They get used in flashlights, controllers, remotes, shavers, etc.
I keep a box of alkaline batteries in various sizes on hand for guests, but it’s hard to beat NiMH and NiCad rechargeables.
@SubArcticTundra Also add XBox game controllers to the list. I have multiple pair of rechargeable batteries. It’s way better than having integrated batteries like in the PS controllers. I can just swap the set out for a full set, right away. Doing this since Xbox 360.
My Garmin Montana GPS uses 3 AA batteries and it’s really handy if you’re in an area without mains electricity since carrying a an extra set (or even buying alcalines in a pinch) will get you going again!
I love these things. I’ve used the same 8 for almost 10 years for my Xbox controllers and VR hand controllers. I can’t imagine how many regular batteries I would have gone through.
Ikr?
I use rechargeable interchangeable batteries wherever I can, but I recently ran into some issues with an ultra-cheap BDC “massage” pillow. The OCP in the batteries was getting triggered and the motor would stop and start spinning for 10 seconds at a time. Tried to add small value resistors and capacitors to it but nothing worked and I had to get a pack of alkaline. Only now do I remember I have a bunch of spare 18650s and USB battery charging boards that I could’ve retrofitted!
Next time add a capacitor instead of a resistor for this
In series or parallel? How would it help?
In parallel. The capacitor smooths out the power and keeps it from spiking and shutting down over and over.
A resistor (in series) would help too but might restrict power too much to work well.
No harm in adding a capacitor.
On almost all my projects the weird behavior has been solved by throwing a cap in it
I remember shopping for a Bluetooth speaker and while I settled on a JBL one, I did consider the IKEA model that takes AAA’s but it wasn’t available to try nor buy - it would’ve been nice to be able to consider one that was externally powered but ah well.
Yeah, the first USB power bank we had at home also used 4 replaceable AAs. I wish this was still common
How old are those batteries? I have some that look exactly like that and they could be since 10 years ago or more, and I swear they still work lol.
Yeah we must have these since like 2012. I’m impressed they still work
There’s nothing stopping me from using my phone’s battery in my toys. The same way nothing stopped me from connecting a small toy electric motor to a straight up power connector to plug into a wall socket when I was a kid.
All you need to do is connect the red and black wires from the battery to the leads on the device. Now, it might cause the thing to break/melt/catch on fire, but that’s not the fault of the battery. 🤷🏻♂️ 🤣
