Li-Ion batteries

I purchased some torches with 14500s claimed to be 2400mAh which I didn't believe. I doubt that they were even close to 850/900mAh as fully charged they didn't last long in the torch. Replacement 900mAh batteries lasted much longer.

Including VAT :-)

No idea about VAT. VAT is not a simple tax as stated by the government when they introduced it on April Fools day.

I guess not, since they tend not to. I'd imagine it has to do with space for the electrolyte and a thick enough conductor not to get too hot and get damaged. I'm sure somebody will find a way though as its a popular size. Is there any better life span or abuse olerance in one over the other? Brian

Why was the AA LiIon size ever invented if it's no good? I've only ever come across LiIon intended products (like torches) that take the larger 18650 size. I only tried the little ones as NiMH replacements. As far as I know, the only advantage to LiIon over NiMH is the increased capacity, and you don't get that with the smaller size.

They are far better at not self discharging

NiMh if left a few months flatten and destroy themselves

Li-Ion is good for a year or more

That's no longer true, since about 10 years ago when Uniross came out with Hybrio, and other manufacturers with similar products. Basically they're just better made NiMH. They don't significantly self discharge, in fact when you buy them they come already charged. Myself I have AA NiMH which I've left on a shelf for 2 years and they still measure as pretty much full.

Piss of with your trolling Hucker.

Well thats news to me and welcome news at that.

Hated NiMh for that exact reason

It was a genuine question. F*ck you.

Funny, I never noticed much drain on the original NiMH (probably lost about 25% in 3 months). NiCad, yes, they were appalling.

The problem is cylindrical batteries are based on a roll of cathode, anode and separator, all tightly rolled up.

The capacity of the battery is proportional to the area of the roll, which is proportional to the length of the unrolled material. The length you can fit in a cylinder is roughly proportional to r^2.

The cell wall thickness is about 0.2mm, which makes an 18650 have 17.6mm for the roll and a 14500 have 14.1mm. By r^2, an 18650 would have 1.56 times the capacity of a hypothetical 14650. But it's a 14500, which means an

Also, don't forget lithium batteries are 3.7V nominal compared with 1.2V for NiMH. So you get 3x the Wh.

Theo

Is your F key not working to god?

I see, that explains why Panasonic (the only make I've found that actually has the capacity they state on the label) don't even bother making them.

Yes, but the AA size LiIon has 1/3 of the Ah, so the Wh is identical.

Mine don't, and I still have loads of them from the pre-eneloop era. Since all eneloop did was to improve the purity of the chemicals, perhaps there were already non-self discharging batteries around before then.

I've got ones from before eneloop came out which I charge after they run out, then leave them in a box. They typically stay in there for a few months, then are used just fine in torches, cameras, all sorts. I've in fact never known an NiMH discharge by itself unless it's very old and has been used a lot, by which time it's usually at the leaking stage anyway.

Yes, but Nicd didnt destroy themselves in the process

They're not DIRECT replacements, but....

In my camera which takes 4 AA NiMH, I can put in 1 LiIon, 1 NiMH, and 2 blanks. Then when I go on holiday, I take half the number of spare batteries with me.

My electric toothbrush takes 2 AA NiMH. I put in 1 LiIon and 1 blank. This runs the motor a bit faster, which was my intention as it cleans my teeth much better.

My room stats take 2 AAs. But they fail to work properly with NiMH, and only like Alkaline as they need 3V, not 2.4V. They work fine with 1 LiIon and 1 blank.

Never known an NiMH get "destroyed". Only 10 year old ones that get tired.