Comment by userbinator | Hacker News Reader

Comment by userbinator | Hacker News Reader

Batteroo says the sleeve and its boost circuitry doesn't introduce any extra risk of chemical leakage.

From http://en.wikipedia.org/wiki/Alkaline_battery#Leaks

The reason for leaks is that as batteries discharge — either through usage or gradual self-discharge — the chemistry of the cells changes and some hydrogen gas is generated. This out-gassing increases pressure in the battery. Eventually, the excess pressure either ruptures the insulating seals at the end of the battery, or the outer metal canister, or both.

In other words by extracting more energy, there is more hydrogen evolved and it will increase their tendency to leak.

This was also posted on an EE forum I frequent, and the opinions on it so far have been mostly negative:

http://www.eevblog.com/forum/reviews/'batterizer'-claims-to-...

IMHO rechargeable lithium is the way to go. An 18650 has several times the energy of an AA while being not much bigger, and can be recharged. They're still not all that common in the West, but equipment like torches, power banks, and portable fans which take 18650s are gaining in popularity.

>equipment like torches, power banks, and portable fans which take 18650s are gaining in popularity

Don't forget e-cigarette mods (power sources). I'd wager they're the most popular application of free-standing (not packaged in a pack) rechargeable cylindrical lithium cells (I have 12 of them personally).

Yeah, if there's one thing I've learned from mechanical mods, it's that I don't want to over-discharge my cells. I'm guessing that your average AA cell won't fail as catastrophically as an unprotected lithium battery due to chemistry but I'd still prefer rechargeables (for most everything) to an endless stream of disposable alkaline batteries (even if I were able to squeeze a little more out of each one).

Lithium definitely isn't as resistant as alkaline to abuse, which is why consumer adoption (at least in the West) has been rather slow. Regular AAs don't catch fire or get dangerously hot when short-circuited, but that's also partly because they don't have the energy to.

Cylindrical hard-cased cells like 18650s are still safer than pouch-cell lipos though.

Deep discharge does not make LiIon cells explode (or vent), it only reduces their cycle life a bit. Though personally, I swap the batteries in mech way earlier than the point where they start getting damaged. At 3.6-3.7V the battery is weak and doesn't produce enough power on the coil. I'd be surprised if people regularly overdischarged batteries.

And the 18650 is about to be produced on a massive scale in the Tesla Gigafactory.

Personally I've recently switched from conventional AA rechargeable NiMH batteries to low self-discharge NiMH batteries (branded Eneloop) and am very impressed - things like my keyboard and mouse were needing to be recharged every 2 days or so and now I can go 2 weeks or more.

Agreed on the greatness of Eneloop: I've used these in my Bluetooth keyboard and mouse for a few years now, and they also do a very neat USB-powered charger.

(Other brands do low self-discharge MiMH batteries too -- e.g. Duracell -- but I've had much less luck with those).

I've got a big pile of Eneloop batteries; I've even pretty much swapped out the old generation for the new low-discharge generation by sheer use and wearing out the old set. It takes a lot but it can be done.

And I can't help but notice that if you take this at face value and this really does multiply alkaline battery life by 8, the economics still roughly work out as a tie with existing NiMH batteries in terms of cost... and if the tech fails to do 8x, which I tend to agree is quite likely for the vast bulk of uses, it still leans in favor of NiMH for most things.

You're mouse must use a lot of power. I use a Logitech mouse (http://www.logitech.com/en-us/product/anywhere-mouse-mx-p?cr...) and I forget it even runs on batteries.

If you have enough light in the room a solar keyboard is also pretty awesome, I had one for the longest time. Kept it until I accidentally broke the keys cleaning it. Keyboard selection is very much based on taste though, so I assume you probably saw one and didn't like it.

> An 18650 has several times the energy of an AA while being not much bigger

They're much bigger.

http://club.dx.com/forums/forums.dx/threadid.457734

I think they're closer in size to a pair of 123A batteries, the type often found in "tactical" flashlights.

I use 14500's in my smaller flashlights. They are the same size as a AA battery. You can also get a 14440 to replace a AAA. (Of course the device needs to be able to deal with the 3.7v batteries.)

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