Built An LED 12V car Battery Indicator

[Qxxx4]

last semester one of our projects was to build a battery indicator for a 12V car battery using surface mount parts. Very tiny board and works perfect....if the battery is over 12V green led lights up, between 11-12 yellow, and if the battery is low you get red. Finally decided to make use of it and mount it in my car. My dillemma...where to put it!

My dads land rover has electronic rustproofing, and when you open the hood you see a cool flashing led telling you the system is working ok. I wouldnt mind installing it under the hood but 1) id have to make really waterproof wiring and a transparent box to put the circuit in, and 2) itd be conveniant to catch that yellow led INSIDE the car when its freezing outside. So my question.....would it be smart to wire the circuit to a 12V source inside the car? Would this be an accurate reading of my actual battery or does the length of wire add unneccessary resistance?

Itd be neat to wire it inside the glovebox, or maybe the center console box, theres easy access to 12V there.

Im aware i wont get a correct reading when the engine is on, as the alternator is charging the battery.

thanks to anyone who knows what the heck im talking about lol Funny how new cars today (like my dads 06 frontier) has gauges for oil temp, and battery level, really neat stuff, but its all the more fun for me as i can do it myself

[slickroger]

I know that the shorter the ground the better. but having really long wires would hardly change the resistance of the wire well not significantly anyway.

And I know exactly what little board your talking about. at the end of the school year i ended up with 2 of those boards. Ive been watching my new In-dash all the time in the truck that circuit would be an excellent way of knowing when to start the truck so i dont kill the battery.

I would say to hook it up directly to the battery for the most accurate reading and just ground the circuit to the closest spot.

I think you should run it to the center console or even the map light unit in the center in front of the sunroof.

[Qxxx4]

those are killer ideas man! i really gotta start getting comfortable wiring things inside the car, its 12V DC but for some reason im always scared of messing something up, but everything is fused so its not so bad