Using house battery to jump start vehicle?

[MrNoodly]

I know that vehicle batteries, used for starting, discharge and recover their power differently that deep cycle batteries do. But in a pinch, is it totally bad to jump start a vehicle from one's deep cycle house battery?

 

[SternWake]

I know that vehicle batteries, used for starting, discharge and recover their power differently that deep cycle batteries do. But in a pinch, is it totally bad to jump start a vehicle from one's deep cycle house battery?

Not bad at all.

A deep cycle battery just has to be about 30% larger to have the same cold cranking amps as a starting  battery designed with thin porous fragile plates for maximum juice for cranking.

Factoring in the fact that all 12v batteries in the standard group sizes are marine/dual purpose batteries, and NOT actual deep cycle batteries, their ability to crank an engine is only slightly diminished compared to a Starting battery.

A pair of 6v Golf cart T-105s in series has about 1100CCA.  Way more than enough for engine starting.

A deep cycle battery that is large enough to provide the necessary CCA is actually a better choice as a battery in a single battery scenario/system.

The only true  flooded 12v Deep cycle batteries are the Trojan T-1275/J150 and J185 along with some super expensive offerings by Rolls surrette.  The rest are just dual purpose batteries with half the rated cycle life.

AGMS blur the line between starting and deep cycle.

The only real factor is the wiring to/from the house battery,  if it can actually supply the demand of the starter, if one is not using a pair of adequate jumper cables.

 

[highdesertranger]

yes you can do it just like stern says. I have done it before. I have also jumped my truck off my 4wheeler. just hooked it up and let the 4wheeler idle for about half an hour. nowadays I just hook a 50 watt panel up to the truck when parked for extended periods. highdesertranger

 

[rvpopeye]

My class A had a switch and solenoid that would parallel the batteries through a huge piece of battery (welder) cable for jumping the start battery OR the house battery ( to start the generator).......worked great.
The starter battery was a group 31 1000cca and the house battery was 2-6volt GC batteries about the same cca's

So....Yup Yup

I've also run the engine using just the generator and a battery charger once when the starter battery died after the alternator failed.

I also have put in this same system in my class C.
Yeah , I think it was very handy to have.......