FS on Ebay 12VDC 5.1Ah Ignition Backup Battery

**TheSpecialist** · 02-04-2004, 08:10 AM

Item number: 2462731720 12VDC 5.1Ah Nickel Cadium recharable battery for $6.99ea.The batteries dementions are 2.4" x 6.2" x 2.5". I use this same battery with my car PC between the ITPS and the power supply. This solves the issue of the machine rebooting when you start the car. You can also run the computer off of the battery directly from 2-3 hours or more (dependind on the amount of attached devices you have). By placing a 1n4001 diode in the circuit you can charge the battery when the engine is running and stop it from draining when the engine is off. More wiring details can be found by reading posted threads here on mp3car.com. The battery also comes with its own male interlocking connector, which is compatible with Radio Shacks 274-222 female connector (not included).Buy now while supplies last.

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMESSE%3AIT

**hman** · 02-04-2004, 10:45 AM

This is a very interesting thing... How would i wire this up? Any diagrams you could show me?

**TheSpecialist** · 02-04-2004, 01:15 PM

there are tons of post on this topic. basically you put the battery in parralell to your suplly voltage. When you start your car it pulls all of your power to start the engine. when this happens in post cars it cause the computer to reboot. The battery would hold the voltage and the computer stays on. I also added a diode ( Pos. side towards the in coming voltge) before the battery to keep the back battery isolated from the cars circuitry when the car is off, but allows the battery to charge while the car is running. Search for "ignition battery" and you'll find more info on this. I put the diode between two blade connectors.

I drew you a quick diagram, see attached.

**chut** · 02-04-2004, 01:40 PM

Hi!
I'm curious about this. Can I wire this before the power inverter and this will keep the system running through the engine crank?
Peter

**NightHunter** · 02-04-2004, 01:43 PM

Originally Posted by chut

Hi!
I'm curious about this. Can I wire this before the power inverter and this will keep the system running through the engine crank?
Peter

I just bought one of these from you, but am curious about the inverter thing too. I can power my Car-PC 2 different ways, but i currently have an inverter hooked up with it.

**chut** · 02-04-2004, 02:06 PM

I'm not selling anything currently.

**TheSpecialist** · 02-04-2004, 02:20 PM

12vdc is 12vdc your inverter won't care who's supplying it. If the battery is before the inverter it will allow you to start and or restart your car without it resetting. The only reason I have mine between the ITPS and the power supply is to aviode the under voltage protection circuits of the ITPS.

**chut** · 02-04-2004, 02:25 PM

I'll take one. Should I purchase it through eBay? It's NiCad, how long till it won't accept a charge anymore? And how much to ship it to 78229 in the US?

Originally Posted by TheSpecialist

12vdc is 12vdc your inverter won't care who's supplying it. If the battery is before the inverter it will allow you to start and or restart your car without it resetting. The only reason I have mine between the ITPS and the power supply is to aviode the under voltage protection circuits of the ITPS.

**hman** · 02-04-2004, 02:29 PM

So looking at your diagram, the diode will make the backup recharge?

Also the SPDT switch, if i use it, i cannot use the shutdown controller i assume.

**TheSpecialist** · 02-04-2004, 03:14 PM

Originally Posted by hman

So looking at your diagram, the diode will make the backup recharge?

The voltage from your car will charge the battery. The diode keeps the battery from back feeding into the car, and discharging the backup battery. This keeps the car from pulling power from the backup batt.

Also the SPDT switch, if i use it, i cannot use the shutdown controller i assume.

the switch is a bypass to the shut down controller for those times where you want to use your car PC with the engine off only.