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.
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.
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
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).
I’ve had horrible performances with IKEA rechargeables. The Energizers pictured above have been much better, even AmazonBasics lasted longer for me.
Huh they work great for me. Which Ladda did you get? I think there was some brown or like yellow ones or something that were made in china and weren’t quite as good I think. Also the LADDA 1900 will have a longer lifetime than the LADDA 2450s. In the same way that Eneloop Pro have fewer recharge cycles than the normal Eneloops.
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
But got damn does it ever put out some insane light! My flashlights turn night into day.
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.
I have a set of lasers powered by them as well. Love that it makes the whole thing a bit larger and durable.
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.
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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.
NiMH AA’s have the same problem.
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.
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Well there aren’t really different sizes of 18650s, if you chance the size it’s no longer an 18650.
The flat vs button top issue can be annoying though
Most 18650’s don’t go down to 2 volts. They should be considered “flat” at 3.4 volts - going any lower risks damaging the battery (unless you know what chemistry it uses, some can go lower safely).
Allowing a rechargeable AA to get down to 0.8V is also risky, if you go much lower than that you will damage the battery.
An 18650 is essentially the same voltage as three AA’s. And the amount of charge level they store is closer to five or six. The size and weight, on the other hand, is a bit more than one AA.
But the biggest advantage, by far, is a lot of devices can be powered by a single 18650 but would require multiple AA’s to have acceptable battery life (or a high enough voltage). As soon as you have multiple batteries thing start to get really complex. Your batteries will never be at exactly the same charge state and that can potentially damage the battery and the device.
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But 18650 size is manufactured at much higher scales than other sizes, and therefore it’s the cheapest, and therefore it continues to dominate.
The main barrier is when you need multiple batteries.
If you install a dozen 18650’s in a device (or thousands in a car), they will work great as long as they’re all at the same charge level and can maintain the same voltage throughout the discharge cycle. If they can’t do that, then the battery could catch fire. Yikes. So any device with multiple 18650 cells will hard wire them together so the user is forced to use and charge and discard the entire set of cells as a single battery.
AA/AAA NiMH batteries won’t catch fire if they’re uneven, but being uneven will damage the batteries. You don’t need to keep them together to be safe, but you do need to keep them together if you want the batteries to last longer than six months. Keeping them together can be a logistical nightmare and it’s the main reason I’ve stopped using them… it’s just too much work to keep all the batteries together (especially if the device is shared in a household or workplace). If you get it wrong, then they don’t last much longer than disposables.
Disposable batteries have the same issue - but since they’re disposable you’re probably pulling four brand new batteries from a packet.
An 19650 cell holds about the same amount of energy as five AA batteries. So there are a lot of devices that can run well off a single battery, and those tend to be the ones that are user replaceable.
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.)
18650s are in no way close to the same size as AA batteries. Your other points ring true and I generally agree with them though.
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)
20V tools are 5S rather than 6S
18-20v tools are 6 cells
That’s not my experience - my preferred brand* offers 18V batteries at 3Ah, 6Ah and 9Ah. They also have higher end tools that take 56V batteries - either 4Ah or 8Ah.
I haven’t opened them up to check, but surely the higher capacity batteries have more cells.
(* preferred brand because it’s the one I already have a bunch of batteries for… I actually regret choosing that brand)
That said, often when a battery ‘fails’, it’s actually just one 18650 that has failed and taken the others down with it.
Sure… but if you replace that one “bad” cell before it takes down the others, the battery might spontaneously combust and burn down your house while you’re (hopefully?) not home. 18650’s in series have to be the same voltage throughout the charge cycle.
The charger for the tool batteries has to have circuits to get all individual cells to the same voltage. They are not simply charging them all at once in series. More complex than that, but there is a second circuit for an alternate config that the charger can make use of to charge.
If one cell is dying/dead, it stops the whole battery from working. Replacing that individual cell would allow the others that are still performing nominally to continue to do so. If it were practical to change one cell. Which it really isn’t. But old tool batteries can be a good place to cannibalize 18650s from if you need them for other uses because a “dead” battery likely still has at least some OK 18650s in it.
The 56-60V tools just has triples of all the batteries with an additional circuit path to let them either function in the 18V 5s or 56v 15s configuration, depending on what it is plugged into. Similar story with the brands advertising 40V tools. There’s a reason they’re all staying on multiples of the 18-20V base.
I literally said there can be more 18650s for each series cell. The “not your experience” you referenced is… exactly the same thing I said. Though it is actually 5 18650s for a base battery, not 6, I misremembered that. 3.7V x 5 cells = 18.5V (which some brands advertise as a max 20V to make the number bigger while others just call it 18V). Each cell is 2.4 Ah, which gets you the base battery capacity. The even-smaller cells are either using pouch batteries or something else that isn’t an 18650.
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
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.
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It infuriates me that we use Wh/Ah instead of Joules for this.
It’s like measuring distances with time – “NYC is 3.4 highway hours from DC” – except doing it in a world where no one has any idea what speed people drive on the highway.
I mean I can’t really blame them for being smaller, the USB port is a lot of value added but is also pretty huge.
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.
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.
These days there’s also Lithium ion AA batteries, with different voltages. You can get them downvolted to anything from 1.5 to 1.8V.
The ones over 1.5V are commonly used in applications with electronic motors, since it allows you to effectively overdrive the toy or whatever it is you’re powering.
Life hax right here
Every battery has a voltage curve though; even alkaline batteries will drop off the 1.5v region after some time. Comparatively, ni-mh rechargeables will hold 1.2v more consistently and for longer than an alkaline, where it’s voltage drops pretty quickly as the battery dies.
This
Nickel Zinc rechargeable, peak 1.8V with 1.6V nominal.
Or newish LiIon cells that operate right at 1.5V.
The best part is that these batteries don’t leak and destroy your devices like alkaline batteries.
Invest in a solid charger (30-40€ will do). You’ll keep it for years, it’ll charge an odd number of batteries as well (unlike some cheap ones that only charge in pairs) and it charges just the right amount, then stops. Some even have battery test/discharge function, and charge more than just AA/AAA.
Then invest in a bunch of rechargeables, possibly Eneloops or something good from Amazon.
Now profit for years to come. The planet will thank you as well.
Honestly single use consumer batteries should be banned.
The Liitokala charges seem nice. I’ve got Lii-PD4 for €13 on AliExpress. Unfortunately I didn’t have any extra money to spare for one with discharge capacity testing, otherwise I’d get the Lii-500.
Just be careful not to accidentally press a button on it right after inserting the battery, while the percentage is still blinking, otherwise you may happen to accidentally override the charging voltage and e.g. give the battery 4.35V instead of 4.2V. boom.
The 18650 should have become the ubiquitous replacement in most applications, but nooo, the manufacturers had to go all proprietary and enforce even more planned obsolescence
18650s can be pretty explosive if not properly handled though compared to traditional Lithium based rechargeables though, no?
There’s more than one lilthium battery chemistry. LiFePO4 is pretty safe even when mistreated. Lithium-cobalt chemistries are the ones that tend to catch on fire, make their pouches inflate like balloons, and so on. I’ve seen 18650s labelled specifically as LiFePO4, so safe ones do exist.
Sweet, I wasn’t sure of the polymer carpets or the lithium nickel ones were more or less explody and murdery
Well, the rechargeable batteries that are least likely to blow up in your face are the ones with the old-style NiMH (nickel metal hydride) chemistry that they use in rechargeable AAs and such. They have lower energy density than the lithium chemistries, so there’s less there to explode. They’re pretty inert unless you stuff them into a charger that doesn’t work properly—a busted charger can set just about any battery on fire. (Why is the NiMH chemistry still used for AAs? Because the normal voltage of a single NiMH cell falls nicely in the middle of the voltage discharge curve of a single alkaline cell. Lithium chemistries don’t have that property.)
If they’re safe enough for teenagers with ecigs, they’re safe enough for general use I’d say
Adult devices != children’s toys for obvious reasons
I have a bunch of Eneloop batteries and they’re great.
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.
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.
I dunno, if you use them infrequently, having to string out a cord shouldn’t be any more of a hassle than for a vacuum, no?
And if you’re buying a cheap, probably-won’t-use-this much tool, I think you can get better power out of a corded tool for the price, which seems like a god tradeoff to me.
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).I have a few, select cordless tools. Drill is the first that comes to mind. I also have a corded drill because it was cheap to buy and has much more torque than the cordless.
Hmmm. Drill might be the only one. Most of my use is around the house so not a lot of need for cordless.
Exactly! It’s a shame that they’re becoming less common as hardware gets enshittified
The batteries in Braun razors are replaceable. They even sell those. It’s not terribly difficult, but you need basic solder skills.
If you’re in the US, Ryobi has changed chemistries once or twice, but they haven’t changed the voltage or physical format of their batteries for 20+ years.
I wish power tool companies would get off the proprietary batteries and adopt the CAS standard https://www.cordless-alliance-system.com/
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.
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I use rechargeables for basic things, keyboards, mice, remotes, and I swap them out maybe every couple of months. I wouldn’t call that annoying. For critical things though I do use alkaline, and that’s for emergencies. Flashlight has a set of rechargeable D’s ready to go but I also keep alkaline ones right next to it in case the power is out for longer. Smoke/CO detectors use alkaline because they can go for so long before needing to be replaced
I feel like in many places they’re getting replaced with a built in battery and a USB port
Yeah, to me this seems like such a strange post. I can easily pick up batteries at most stores I go to and use them in various stuff in my home. Never thought about them phasing out right now, but when I think about it I guess it’s true, I see a lot of gadgets that just charge with USB plugs now.
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!
Just saying modern devices could also have interchangable batteries. There are standard lipo pouch sizes and standard lithium cilinder sizes.
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.
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
That’ why i actively look for battery instead of akku in some wireless devices. They are the closest to universal akku size we’ve got. Now they only need to be flater. And charging over USB-C would be nice too.
Does “akku” mean a built-in battery? Google tells me it’s German or Finnish?
Whoops. Yes, Akkumulator = rechargable, Batterie = one-use
It is a German word (short for Akkumulator), but we call batteries that you can replace Akku too.
We here don’t, but maybe thats different in other german speaking parts.
Yes, I was speaking for Germany. No idea what an Eidgenosse would say
