Looking for a 14500 sized battery maximum 3.7 volts.

I have a little project in the near future where I will be using this driver http://www.intl-outdoor.com/boost-12aa-cr123a-circuit-board-p-537.html?zenid=16c83db665ac2f2fd20f476b2446c278 . I have checked with IOS and the maximum voltage this driver will take is as advertised, 3.7 volts. It will be used in a single cell flashlight. I have googled and searched and come up with nothing. All the batteries around this voltage seem to be 16mm in diameter. Am I stupid or is there a battery out there.

I know AA is 1.5 volts, and 14500 are 4.2, but I can’t think of any batteries which give out 3.7volts, unless you run-down a 14500 and check it with a DMM until it reaches 3.7V and use it then.
Other than that I can’t think of any…

You could use 14500 primaries which are that voltage.

LiFePO4 has a max charge voltage of 3.6V and they are safe.

Thanks guys. Any links would be handy.

( Suitable for 1 or 2*AA batteries, 1*CR123A(3V) or 1*LiFePo4 )

its better to use another driver ,14500 might work but its not 100% sure.

or if you want to use those : http://www.batteryjunction.com/titanium-cr14505-craa—3v.html (3v primaries)

Of course 14500 will not work, they are 4.2 max voltage, that's why you can use LiFePo4 cells they are 3.6V max.

Thanks for the link. $20.00 shipped to Australia for 4. I forgot to mention, yes I am stupid, must be rechargeable.

LiFePO4 have higher voltages than that cell. It says 2.0 discharge voltage, too low. Anyway those are primary cells not secondary cells.

LiFePO4 should be 3.2V nominal voltage , 3.6V full charge and 2.8V discharge

The flashing to indicate which protection is engaged is a neat function.

I picked up these Coolook LiFePo4 3.2v batteries and charger and they seem pretty good. They come off the charger around 3.5 to3.6v. I use them in small lights that 4.2v is a little too much for but you want that extra boost from 1.5v. Pretty handy to have on hand. They come with dummies that I use in some 2XAA lights. Depending on the light ill use one 3.2v and a dummy or sometimes a 3.7. Nice to have a happy medium to be able to expand your repertoire.


Thanks OuchyFoot. Looks like the best offer so far. What I'm after cant be a very popular combination,

2 AA lifepo4 less of $4,5(and 1 dummy cell to use 1 lifepo4 and 1 dummy instead of 1,5 primaries in series)

If you were in the US I would suggest Walmart 14500s but you aren't. :'(

Yes scaru, I'm a long way from the US. Its on my list to visit. The only thing stopping me doing things on my list is money. Tossing up whether I should get a couple of these to try for the heck of it. http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=25025

I have read mixed reports about this chemistry. I can get two delivered for about $6.00.

It couldn't hurt to try but remember you need a special charger to charge them. I have used those and they do best if you do not fully discharge them.

Or you cold order this and take it apart for 3 lifepo4 14500s. The advantage to lifepo4 is they are indestructible. Or if there are any places that sell solar yard lights near you you could buy one of those. They generally have a 14500 in them and with a bit of work can be turned into a good charger for lifepo4 batteries.

Sorry for posting 3 times in a row, my iphone has trouble with editing and I forgot the link.


Thanks. I have a couple of chargers that should charge them ok. If the other batteries above were a bit cheaper I would try them both. Cheers.

You could try these.