battery isolation

[ncc74656 2]

i had some issues at sears but now finially got my order placed. i got 2 group 49 AGM batteries for my truck. i currently have 2 group 31 lead acid batteries that still work (sort of) but are rather lack luster for starting the truck.  so my thought was i save 15.00 on the order per battery to trade my 120.00 group 31's in (they are 1 year old) OR i could keep these 2 as a secondary isolated battery bank that i could abuse as i wanted with out much worry.  do we think this is a decent idea or should i just core charge them?  they are 1150CCA 195RC batteries.

 

the truck has its stereo and a 16K Lbs recover winch on the front. my thought was that while the truck is running it should not matter what batter is plugged in where as the alternator is handling it all. however i would want to have 2nd ignition relayed into a isolater so the liquid batteries do not drain the charge from the AGM's.  

 

i was thinking of wiring these batteries into the system while the truck is running to give more over all battery power for the entire system and power grid to use and while off the accessories could run off these older batteries and i could install a switch to put hte winch on just these guys so i dont drain the AGM's.

 

thoughts?

Edited December 24, 2013 by ncc74656

[jonbearsmt 919]

i didnt read all of your post...

 

 but you do understand that a isolator only works when the vehicle is off right?

[ncc74656 2]

i have not used one or worked with one before so idk. i dont see how it would matter to isolate while the engine is running so that makes sense. so the isolators trip over only when the engine is running; is what your saying? when the engine is off and only accessory is on the isolator does not enable both battery banks right?

[lithium 358]

http://www.bcae1.com/battiso.htm