2y ago

I just wanted to take a minute to appreciate interchangable batteries

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.

125 comments

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.
- 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.
  
  Wait, do they not make AA-sized 18650 batteries?
  
  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)
  
  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.
  
  20V tools are 5S rather than 6S
- 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.
- 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.

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.
- 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
- 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
- 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.

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.
  
  If they're safe enough for teenagers with ecigs, they're safe enough for general use I'd say

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.

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.
  
  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).
- 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.
  
  I feel like in many places they're getting replaced with a built in battery and a USB port
- 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!
- 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.

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?

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?
  
  It is a German word (short for Akkumulator), but we call batteries that you can replace Akku too.
  
  Whoops. Yes, Akkumulator = rechargable, Batterie = one-use

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?

My mouse uses batteries too, Just swap out once it dies on me.
- My wireless mouse is running on the same 2 AAAs for over a year already. I have no idea how. They still show 1.2V. I expected like a week or two.
  
  The logitech g305 runs on a single rechargable AA for half a year and is probably the only reason I even considered a wireless mouse
  
  I use a Logitech Marathon M705 mouse that lasts 3 years on two AA batteries, according to Logitech. I've got Eneloops in it that I've been using for around 10 years now, and I've had to charge them maybe 4 times in total?
  I've got an older model. They cheaped out on newer revisions, making the plastic thinner and replacing the metal scroll wheel with a plastic one.
- All month, because rapoo energy management sucks.

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!

The single battery cells in electric cars are pretty much already standardized in size, just the assemblies and cooling systems are not.
- That's true for kinda sorta everything? Battery manufacturers don't want to have to deal with creating a bunch of custom battery runs, so they end up standardizing and higher level manufacturers buy from there. This is especially true in situations where space isn't at an absolute premium (like it is in a phone). Open up the battery pack for your cordless drill and you'll find very standard batteries inside there, probably hooked up in series to get to the desired voltage.

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

If we're gonna keep putting batteries on stuff we'd better put these

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

It's also really fun to scream AA
https://www.youtube.com/watch?v=_asuhfYa5_4

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. 🤷🏻‍♂️ 🤣

Uh, torches use fire yah limey
- Lol they must be called flashlights your side of the pond
- You're still using fire for your torches? My condolences Uncle Sam, I didn't realise how bad things had got over there!

I wouldn't say they're out of fashion - a lot of smart home devices are moving away from disposable cell batteries and over to rechargeable batteries.
- To built-in lipo batteries that go bad after a few years and you have to trash your device or tinker?
  
  No - rechargeable AA/AAA batteries.
- Do you mean built-in rechargeable batteries? Because that's way worse than removable batteries.
  Zigbee smart home devices last a very long time on cell batteries (CR2050 or something similar) that I'm not really worried about those. I've got door sensors that have been going for over 2 years on the same batteries.
  
  No - look at the IKEA smartphone line (TRÅDFRI and the like). They have stopped producing Zigbee devices that require CR2032 batteries and have released larger units that take AAA/AA rechargeable batteries.
- That's good to hear, I had a feeling it was all moving in the direction of glued in battery + usb

Since I got those from Ikea, I just want devices to go back to those types of batteries instead of internal battery packs. Still got to appreciate the Xbox controllers sticking to that principle (for now).
- Exactly. The trend of switching to built in batteries + USB is dumb.
  
  Don't get me wrong - I think an included battery that's rechargeable through USB is fantastic. Less customer inconvenience. But they should either go with a standard that's easily reproducible or go with regular rechargeable batteries.

Li-Ion solved this problem.
- If it was so easy to replace them, with each Li-Ion battery being different for every type of device.

125 comments