Small tractor/motorcycle batt Light in truck?

I was in my "thinking" room again today /ubbthreads/images/graemlins/smoker5.gif and had a great idea. /ubbthreads/images/graemlins/smile.gif I think /ubbthreads/images/graemlins/thinking.gif
So, I thought I would post it here and see if it would work out well, and if any of you had anything to add, on how to do this

better.

I have been trying to pick a light to keep in my truck at all times.
I want something really bright, and even more important, run alllll night in case of an emergancy.

So, heres what I was thinking.
Get a metal Ammo box, and put a small tractor/motorcycle battery in it. (these are about half the size of a regular truck batt,

or even smaller)
The light would consist of a 5W LED and probably a Mag head and reflector mounted on top the ammo box.
I am not sure what circuit, if any to use yet though, I may try to just resistor it. But I would like the option of dimming it.
I want to push about 1.5 amps to the 5Wer.

I was thinking of running a nice incan, and having a smaller 5Wer head on it also, to make it duel purpose, but I pretty much

know nothing about incan lights lol.
Any recommendatios on what a good incan bulb would be for a 12V batt?

Now, heres the cool part. /ubbthreads/images/graemlins/wink.gif
Why use such a huge battery?
I plan to wire it in parralell with the trucks battery. This will serve duel purpose.
The truck will be charging, and keeping it charged, just like it does its own battery. That way, its always ready when I need

it.
Second, the lights battery will serve as an extra bit of power for when the truck needs it. Seeing how I run a after market

stereo, lights, and other various add-ons, that should help slightly.

So, theres my idea, anything to add?
Mainly, I am not sure what circuit to use, maybe an nflex? But that wont push quiet 1.5 amps to teh 5Wer I dont think.
And, do I simply wire in the lights batt in parralell with the truck batt? Or is there a better way?
And any input on maybe adding an incan bulb to it also would be great.

Thanks for the help guys.

-John

Hmmm, The alternator in your truck is internally regulated to a current flow that charges the 1 big 12v cell. Not sure what addint another cell of different size and ?amperage? into the loop might do in that respect.

Sounds like a descent enough ideal Instead of using one of those kinds of cells in an ammo box i would probably have opted to use cells from a computer Batery backup (UPS) so i could fit them in a smaller ammo box.

Going to put the head on a swivel of course right?

Shane,

I think as long as its 12V i will be ok,
Those bike batts are pretty high amps also, but thats somethign I need to look into still.

Yes, the head will swivel, at lest up and down. /ubbthreads/images/graemlins/smile.gif

It was brought to my attention, that I could also use a isolator, to keep the bettery "seperate" yet, still charge off the alternator.
But, also be able to switch off the isolator, to let the light batt hell out the truck batt.
http://www.jcwhitney.com/autoparts/ProductDisplay/c-10101/s-10101/p-166200/mediaCode-ZX/appId-385993

Hi Jtice:

Why don't you just go over to Kragen or Autozone or whatever your favorite auto parts store is and pick up one of those 12 volt emergency car-starting rigs that come with built-in cig lighter (both male and female) plugs so you can power doo-dads off the thing or charge it directly from your cig lighter whenever you want. Usually they're fused and some even have little built-in LED's that signal charge level etc etc. I have one sitting out in my garage that I bet I bought 10 years ago and amazingly it still seems to work!

scotto,

Thats not too bad of an idea. That sort of is what I am wanting to build, but more toward the Light side.
I have even seen those with builtin flashlights. But I am wanting thos to be mainly a light,,, that seconds as a power source.

sotto, those car jumpers push a HELL of a lot of amps and probably wouldnt be the best thing. the way i see it you could just keep a rechargable pack plugged into a standard charger that has a 12v dc plug like a cigarette lighter plug and just peak them off of a 15 minute quick charger if they start to go dim while you're using them.

Seems like you could hook your "small" battery right into the cig lighter, since the car's system floats around 14.4 volts anyway, so the battery would be perfectly charged and I would think, everything would stay balanced nicely, as long as both batteries are in good shape.

The additional battery is a load on the system and will not really help run any accessories or lights unless the truck is off. The alternator does all the work.

You could use one of those 5-10 watt landscape lights (at Home Depot, etc) and that should let you run it all night and it has the reflector and bulb included. Anything larger and you wouldn't get a 10 hour run-time. Or you could get a 12 volt fluorescent and that would give you all-night run times, but I've only seen that as part of a 12 volt spot.

Small motor cycle batteries are not always cheap.

The important part about an isolator is that it will keep a bad cell in the main battery from discharging the other.

I'd wire the battery to a switched circuit so that it will not draw from your main
battery while the motor is turned off.

I like gel cells for these applications because you don't have to worry about acid spillage when you move the light to where you need it.


Daniel