help finding battery pack

[neo71665]

I'm working on setting up my hunting bike to get in and out of the woods. I'd like to put a

http://www.amazon.com/dp/B00GJKXW8M/?tag=cpf0b6-20

on the front and run it off a pack(s) in an ammo box storage mounted to my front rack. I've looked at everything from building a pack using my own 18650 cells to finding something RC car/helicopter related. Space and physical protection are not really an issue I just need help figuring something to run in the 4 at least to hopefully 6 hour run time. Not overly worried about weight but I don't want a group 73 lead acid battery weight either.

I've looked and looked till my head is about to spin. I've found a few threads of guys talking about doing something like this and one guy that claimed to done it but nothing with any details (maybe I didn't dig far enough back or use the right terms).

thanks

 

[poguy]

That's 18 watts, so 1.5 amp current draw at 12 volts and more as voltage goes lower. That's 3 LiPo's in series. A couple things:

First, to get 4-6 hour runtime you need a bunch of these in parallel. High current draw means you get much less output than the stated capacity. I would start with 4 or 5 sets in parallel, totaling 12 or 15 cells. That's a lot of batteries.

Second, you need a hobby charger. And a cable that lets it charge each part of the series pack by itself. There will be 4 wires for a 3s pack.

Perhaps you would be better off using something else. Some of the cheap Chinese bike lights are decent.

 

[Savvas]

Impressive looking unit but it seems to me that that's the wrong light to start your project with. If you want it as a bike head light (i.e.; to see where you are riding in the woods) it's probably quite unnecessarily large and 'floody'. For headlight purposes there are many lights - both cheap and very expensive - that are much smaller physically and will do an excellent job without battery complications. The Lupine Betty and the many Chinese copies come to mind. If you want the light to actually hunt with then surely you want a very narrow, far-throwing spot beam. I'm no hunter but I read that there are several simple single-LED flashlights with very narrow beams which are apparently the bee's knees. For a 4-6hr run time you'd just carry a few extra, charged 18650 cells. Or you could invest in one of these and not worry about being in the dark again!
If you go down a route where you end up having to repeatedly charge separate LiPos and then hitch them together, worrying all the time about keeping them safe without catching fire, then I reckon you're courting unnecessary complication. I'd just choose lights that do one or the other (or both) tasks using the same protected 18650 cells to keep things simple and convenient.
my 2 cents,
Savvas.

 

[Milw light]

I would probably use a small motorcycle lead acid battery. You can do it 18650's at quite a cost.

 

[Overclocker]

I'm working on setting up my hunting bike to get in and out of the woods. I'd like to put a

http://www.amazon.com/dp/B00GJKXW8M/?tag=cpf0b6-20

on the front and run it off a pack(s) in an ammo box storage mounted to my front rack. I've looked at everything from building a pack using my own 18650 cells to finding something RC car/helicopter related. Space and physical protection are not really an issue I just need help figuring something to run in the 4 at least to hopefully 6 hour run time. Not overly worried about weight but I don't want a group 73 lead acid battery weight either.

I've looked and looked till my head is about to spin. I've found a few threads of guys talking about doing something like this and one guy that claimed to done it but nothing with any details (maybe I didn't dig far enough back or use the right terms).

thanks

http://www.amazon.com/gp/product/B00CWY2IF2/?tag=cpf0b6-20

3M projector battery pack. inside are three 18650 cells in series, 2100mah. has built-in protection circuit so just plug in your light and you're good to go

just buy a bunch of them and parallel them for more runtime

i have like a hundred of these batteries. chinese Amperex brand cells but they're pretty decent for the price

then goto hobbyking and get a cheap imax b6 clone for like $16