battery supplier in (or near) Australia?

Savvas

Enlightened
Joined
Jun 11, 2010
Messages
222
Hi Folks,

I wonder if anyone is able to point me to a local (to Australia) supplier of 'custom' batteries similar to Battery Space in the USA. BS have a small AAA 'triangular' NiMH 3.6v battery that I want for a low profile helmet light I'm building. I'd buy from BS except the postage prices are utterly outrageous. They apparently only use FedEx and it would cost me $60 or more to get my hands on a couple of $15 batteries - too ridiculous for words!

So is there a company in Australia who can meet my need?

ta,
Sam.
 

Steve K

Flashlight Enthusiast
Joined
Jun 10, 2002
Messages
2,786
Location
Peoria, IL
hi Sam... no idea who sells battery packs, especially in your area!

however... can you make your own packs? I've done this by purchasing tabbed AA's and wiring them together as desired. I think I did this with some D cell nicads back in the incandescent days too. Tabbed cells should be a bit easier to acquire.
 

Savvas

Enlightened
Joined
Jun 11, 2010
Messages
222
Thanks Steve,

Yes, sensible suggestion. I've done a little more research and discovered that tabbed NiMH AAAs are relatively easy to get hold of locally. But in the process I've also encountered some doubts. My project involves an old Bell Muni helmet I've fixed up (it had a busted strap buckle which I've replaced, no thanks to Bell who were no help at all). I've tricked it out with lots of reflective tape. It has little plastic 'brackets' front and rear designed to mount a pair of Blackburn Flea lights. I actually have an old set of these in the junk box but of course - like many things - they never really lived up to their promise. They were great as 'be seen' lights, which is why I bought them a few years ago, but the tiny lithium button cells inside seem to have given up. I've read somewhere that it's possible to open them up without too much damage so my project was to try to wire them appropriately to power them both together with a small external battery. I had thought that the 3.6v from a BatterySpace external 3xAAA NiMH 'triangle' pack nestling in one of the helmet's vents might do the trick, the plan being to plug it in to my USB portal work to charge like this. However the reading I've now done suggests that the USB socket's 5V won't easily charge a 3.6v NiMH pack, even though BatterySpace reckon it's possible. So I'm re-thinking battery options. This is strictly a 'be seen' project and has no aspirations as a headlight. I'm just trying to make best use of stuff that's lying around. I guess I'd like to ask the list if others have tried using a USB source to charge NiMH packs, and specifically a 3xAAA 3.6v?

Sam
 

Steve K

Flashlight Enthusiast
Joined
Jun 10, 2002
Messages
2,786
Location
Peoria, IL
applying 5v to a 3.6v nimh battery pack will overcharge the battery. There are a couple of options and maybe more...

option 1 is to add a series resistor to limit current to a safe trickle charge current. For nicads, this was usually C/10. For nimh... I think it's a good deal less. You'd have to check the datasheet to get an actual number. The downside is that it can take quite a while to recharge the battery.

option 2 is to add a series voltage regulator and just charge the battery to a fixed voltage. This isn't the optimal method, so you'd need to set the charge voltage to something safe. Again, the datasheet should be consulted. My guess is that you could safely charge to 1.3v per cell. The battery wouldn't be charge to 100% capacity, but might be good enough.

option 3 would be to put together something using a proper nimh charge controller that will do proper charge termination. Perhaps you could buy a demo board for one of the many nimh charge controllers made by Linear Technology and others?
 
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