how hard is it to add a second battery?

[mr bill]

Wife just bought a 1998 Tahoe. The lift gate was open for 24 hours and the dome lights drained the battery. I noticed a second battery tray under the hood and wondered how hard it would be to install a second battery. There seems to be a positive cable running from the fuse box over the fan shroud to the battery that is doubled up with the positive cable leading to the starter. I dont see a ground cable near the empty battery tray. Is it a matter of installing a second battery then connecting the positive cable from the fuse box and adding a ground? What about isolating the second battery and charging issues. I would really appreciate any info.

 

[SunlitComet]

from the factory as an option the second battery pos cable was ran thru a solenoid that was operable when ignition was on. so when it was on it would charge are supply supplemental power as need. it ultimately hooked to same spot as main battery did on the power block. of course with ignition off it was isolated from power block and loads on its pos terminal could drain it for usage with out taking the main down with it. just about all the oem parts are still around to make it work that way or you can use an aftermarket method to.

However, you can switch the interior to leds to slow down the drain significantly if it happens often or put a low power cutoff relay module in place but will have to be wired on just the lighting circuit for the actual cutoff point or it will kill "memory" to the onboard computers and really make your life miserable.

 

[Tahoe_96]

+1 on the LED lights.... after switching to LED's I left one of my map lights on for atleast 36hrs and the truck did even hesitate to start after that