AA/AAA rechargeable. Why no Lithium ion 1.5v ?

Forums › Gadgets, robotics, home automation, electronics (including wearables) › AA/AAA rechargeable. Why no Lithium ion 1.5v ?

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seoras

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#2044576 27-Jun-2018 09:04

neb:
seoras:

It came with a USB charger which also double as a nice little LED torch too.

The charger takes 4 batteries at a time (AA or AAA).

I didn't want this post to come across as a product advertisement. I'm really just looking for pit falls here. You know "if something sounds too good to be true...".

Something doesn't make sense. Why would such a good product not be openly available here in NZ?

Probably because they're not really that good for what you're paying. They use a buck converter to get the steady 1.5V, so you'll have a higher self-discharge rate than LSD NiMH's, and an even worse one if powering low-current-draw equipment over a period of time. The capacity is carefully given in mWh rather than mAh, a back-of-the-envelope calc with freely invented figures for conversion efficiency etc puts them at about the 1500mAh mark, vs. close to 2000mAh for equivalent NiMHs. So it's hard to work up much enthusiasm for something that's probably not much better than, possibly worse than, a cheap NiHM AA.

I count "probably" twice in there. :)

The theory doesn't match the reality I'm afraid. NiMH are pathetic and the Li-ion's I have are better even than disposables.

I'm not talking theory here I'm sharing my experience of using them. Anyone else?

I think we've already established that the published theories put them down as not worth investigating.

I'm saying that I have investigated and the practice doesn't match the theory. So which is real? Tested or theorised?

Safety concerns would be more convincing, that's what I'm really looking for.

neb

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#2044884 27-Jun-2018 17:13

If you're not willing to accept advice from people, why did you ask in the first place? Just go ahead and buy whatever you want and do whatever you want with it, if you think it's better than anything else then good for you.

seoras

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#2044923 27-Jun-2018 18:30

neb: If you're not willing to accept advice from people, why did you ask in the first place? Just go ahead and buy whatever you want and do whatever you want with it, if you think it's better than anything else then good for you.

If you've nothing to add of value why don't don't you just stay out of this thread?

If anyone has EXPERIENCE with these batteries I'd expect to find them on Geekzone. Right? No?

If I wanted to google for articles and "facts" then I'd have done that myself, which I have. Still waiting for some real insights here.

I'm interested in hearing opinions but I'm not interested in being told to shut up and bugger off by those who don't want holes poked in arguments and counter evidence to perceived wisdom.

Healthy discussion my friend, heathy discussion... That's what a forum is for isn't it?

There's something really smelly about the AA/AAA form factor battery market place. As I've said in a prior post it smells a lot like the incandescent light bulb complacency. An archaic technology which was wasteful in both power and resources. The early low power, long life alternatives were pretty awful. Expensive too. Now they are mainstream, backed even by legislation in some countries (Aussie), the tech has improved and the price has dropped. Who'd buy a 100W incandescent now?

If I come across as defensive about the Li-ion's that I have it's because I'm really surprised and disappointed at the way they've been brushed off on here as rubbish by those who've never actually tried them. I will be buying some more. I'll never buy another NiHM or disposable again. Feel free to go the other way, as I said at the start I'm not selling. I'm asking. I'll listen but I don't have to believe or agree.

Scott3

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#2044925 27-Jun-2018 18:33

Has anybody tested these against the likes of a premium Low self discharge NiMH (i.e. Eneloop pro).

I gave up on rechargeable AA's years ago, but was essentially forced to get some when I got a external flash for my camera. (all canon flashes are AA powered. One aftermarket LiIon flash is available out of china (very well reviewed for pro wedding use (generally manual settings) etc.), but I wanted to stick with cannon for better auto functions).

I have been really impressed with the LSD eneloops. Flash recycle time is much faster than Alkaline batteries, and they last for much more flash pops. Also most AA stuff is engineered to run well at 1.2V as while alkaline batteries start at 1.5V, they quickly fall below 1.2V.

Does anybody know if the capacity rating on the LiIon rechargeable is before of after the voltage conversion? If it is actual usable power, they would be on par with at 2500mAh eneloop pro at 1.2V (2500mAh @ 1.2V = 3000mWh).

seoras

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#2044936 27-Jun-2018 19:13

Scott3:

Has anybody tested these against the likes of a premium Low self discharge NiMH (i.e. Eneloop pro).

I gave up on rechargeable AA's years ago, but was essentially forced to get some when I got a external flash for my camera. (all canon flashes are AA powered. One aftermarket LiIon flash is available out of china (very well reviewed for pro wedding use (generally manual settings) etc.), but I wanted to stick with cannon for better auto functions).

I have been really impressed with the LSD eneloops. Flash recycle time is much faster than Alkaline batteries, and they last for much more flash pops. Also most AA stuff is engineered to run well at 1.2V as while alkaline batteries start at 1.5V, they quickly fall below 1.2V.

Does anybody know if the capacity rating on the LiIon rechargeable is before of after the voltage conversion? If it is actual usable power, they would be on par with at 2500mAh eneloop pro at 1.2V (2500mAh @ 1.2V = 3000mWh).

If you are anywhere near Cambridge where I'm based I'd be happy to loan you mine to try them. I'd be curious to see if they were up to the job for what you have in mind. They claim to be 2800mWh @ 1.5v which would be 1867mAh. Mine are a few years old. The same ones from Kentli today are now rated at 3000mWh (=2500mAh).

I got really sick of using NiMH which I've always found to be far inferior to your duracells et al. In this more enlightened period of history, where we are supposed to be more environmentally aware, you'd think these land filling disposables would be next to go into the history books.

Bung

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#2045025 27-Jun-2018 21:26

Scott3:
Has anybody tested these against the likes of a premium Low self discharge NiMH (i.e. Eneloop pro).

I gave up on rechargeable AA's years ago, but was essentially forced to get some when I got a external flash for my camera. (all canon flashes are AA powered. One aftermarket LiIon flash is available out of china (very well reviewed for pro wedding use (generally manual settings) etc.), but I wanted to stick with cannon for better auto functions).

I have been really impressed with the LSD eneloops. Flash recycle time is much faster than Alkaline batteries, and they last for much more flash pops.

Your flash recycle time may be affected by the current limiting of the Li-ion AA around 2A.

Samsung

Shop now on Samsung phones, tablets, TVs and more (affiliate link).

Scott3

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#2045109 27-Jun-2018 23:46

Bung:

Your flash recycle time may be affected by the current limiting of the Li-ion AA around 2A.

It would need to be a pretty grunty voltage converter to keep up with the draw of a speedlite. Any idea what happens when the buck boost converter hits it's current limit? - would it overheat, shutdown, or drop the voltage?

seoras:

If you are anywhere near Cambridge where I'm based I'd be happy to loan you mine to try them. I'd be curious to see if they were up to the job for what you have in mind. They claim to be 2800mWh @ 1.5v which would be 1867mAh. Mine are a few years old. The same ones from Kentli today are now rated at 3000mWh (=2500mAh).

I got really sick of using NiMH which I've always found to be far inferior to your duracells et al. In this more enlightened period of history, where we are supposed to be more environmentally aware, you'd think these land filling disposables would be next to go into the history books.

I'm a bit far to borrow them I'm afraid.

I'm fairly happy with the eneloop pro's in my speedlite (external camera flash). I think this application (draw heaps of current for short bursts) is pritty well suited to that technology. (that said from an experimental point of view, I am really interested what the actual outcome would be of a head to head test)

The application I have in mind is a baby nail trimmer. Basically a oscillating sander powered by a single AA. This one runs awesome with a fresh alkaline battery, but performance quickly drops. I actually haven't tried an eneloop in it (I try to keep my camera sets together). I think this would be a great application for the Li-ion batteries as the 1.5V output level would allow the motor to run faster that the 1.2V output off a Low self discharge NiMH.

For reference, eneloop vs alkaline:

The Li battery plot would be basically a flat line at 1.5V, until the battery runs out (as the voltage is getting converted to be 1.5V)

richms

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#2045118 28-Jun-2018 00:47

There is very little reason to worry about throwing out a modern single use battery other than the waste of the component materials in it.

I have virtually got nothing left that is worth running any form of rechargable cells in. Possibly only my LG remote would benifit, if I put nimh in it, then its IR emitter for turning the TV on and off becomes pretty hopeless needing line of sight in the room, but on alkalines it quickly runs out to the point I get onscreen messages about it being low all the time.

Other remotes are best served with alkalines, and I dont really have anything else now. Everything else is USB charged with internal batteries or an 18650 powered flashlight which has displaced my older AA maglights. In the past I got some NiZn rechargable to try, but the 2 different chargers I got were total trash and took ages and didnt really have a great build quality. The NiZns seemed to run everything ok, but that was at the tail end of me needing lots of AA cells so I ended up just sticking them in a box in the shed.

These lithium ones might work really well, or it might be like that thing that Dave Jones royally trashed that was supposed to make alkalines last longer by being a DC-DC converter. I suspect it would vary greatly depending on the load profile of the item.

In anycase, a few years back I would be all over these to have a play with, but now its just a bit meh really.

Richard rich.ms

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