Connecting 2 batteries in a computer controlld 4.0L YJ

[M240_Storm]

1054102

The idea:
To install 2 batteries in the jeep. I already have them.
To connect both of them through a switch that will connect as selected by the switch. It will enable to use battery one as the only battery.
Or it will enable to use battery two as the only battery.
Or in extreme cases connect both in parallel.

The need to have the switch is because I have 2 batteries and they have the same electrical characteristics but they are not the same age, so one battery will not charge the other.

The problem:
Would the switching affect the controller (Computer)?
When would it be OK to switch Engine on (probably not) engine off?
Would it affect the controller as regards to parameters saved on it?

Thanks for any comments or ideas.
Alon
[addsig]

 

[jcooper]

1054110

You have to really careful with this. Look around online for a prebuilt setup.

http://www.sleeoffroad.com/technical/tz_dual_batteries.htm
http://www.rightcoastcrawler.com/billaVista/dual_battery/my_dual_battery_setup.htm

Check that out. Not sure if it applies, but it will probably guide you in the right
direction.

Your main problem will be that as the switch rotates, it must disconnect from one
battery before connecting to the other. If this doesn't happen right, you'll get a 24v
spike in your electrical system. Read: major fubar. Go with a marine (yaknow, boats)
switch.

For more info, do a search for "dual battery marine switch" on google. If it isn't coming up
with what you want, add in the word Jeep.

Cooper.[addsig]

 

[dingus]

1054175

here's something that summitracing.com offers... looks like a complete kit:

http://store.summitracing.com/partdetail.asp?part=20955[addsig]