6 replies to this topic

[pawleyk]

Hello all,

 

Posted this over at ExpoPortal also, but wanted to get a variety of opinions.

I've been researching dual battery setups, but I'm still unclear as to what I actually need. It seems that most articles and write-ups are discussing the intricacies of various isolators/separators/relays.

My question is- Do I actually need any of those for my particular setup? Why not simply wire the batteries in parallel?

I've got a 2005 silverado HD 6.0L gas. It's the very basic work truck edition, rubber floors, cranker windows, etc. No fancy electronics or crazy stereo systems. The under-hood battery(ies) will only be responsible for the standard starting and truck accessories, plus the very occasional winching duties, a 12v onboard air system, and possibly a small inverter in the cab to charge a tablet or two while on the road.

I really only want the dual battery setup for the increased capacity and the added peace of mind that comes with redundancy. Most of the discussions I've come across basically treat the second battery as a "house" battery, which I'm not sure I really need in this case.

The plan is to put a FWC on the back in the next couple months (ordering it tomorrow..  ) which will obviously connected, but isolated, from the starting batteries. The camper will have solar and it would be nice to have a system that charges both directions to keep the truck batts topped off during longer, sun-filled stops.

I'm only throwing the future camper plans in to give some context to expansion plans, but I'm really just trying to figure out what to do with the truck batteries in the meantime.

Edited by pawleyk, 25 October 2015 - 10:24 PM.

[ntsqd]

You can wire them directly in parallel. If you do, the commonly accepted thing is that both batteries need to be the same size, type, age, and preferably from the same mfg. lot. Without a separator you will draw them both down at the same time regardless of the demand type. Our CTD's starting batteries are wired this way from the factory, and my old '79 Suburban with dual batteries was also wired this way. 

 

When I moved the dual batteries to our '91 Suburban I added a Voltage Sensing Relay in parallel with a marine battery bank switch. That allowed me to alternate which was the "house" battery and which was the starting battery, and allow a self "jump-start" should it have been necessary.

[Kolockum]

I have two batteries set up in parallel with an 80 amp isolator set up between the two. One battery is for my camper and the other is for my truck. When the engine is off, the isolator disconnects the truck(starting) battery while the camper battery stays connected to the camper. I also wired all the 12v outlets in the truck to my camper battery so I do not have to worry about draining my starting battery.

 

I did not like having my camper battery tucked away out of reach in the front void between the wood camper and metal truck bed. And removing/installing the camper battery every time I took the camper on or off got annoying.

 

If necessary I can engage the isolator and jump start with my camper battery.

Edited by Kolockum, 26 October 2015 - 03:14 AM.

[Ramblinman]

I have 2 Batteries - one is isolated. This is the only way I would do it. WHEN, I leave something on ( which as happened more than once) I always have the other battery to jump. Also, I have swapped it out with the battery from my camper, when the camper battery could not be charged.

2 truck batteries give me peace of mind.

[pawleyk]

Thanks for the suggestions and setup examples everybody,

 

I think I'm liking the idea of an "isolated parallel" system.. a simple parallel system, but with a serious relay between the batteries that disconnects them from each other when the truck isn't on. That way if one is drained accidentally, I'll still have the other for starting, but won't have to jump them at all.

 

-KP

[Basin Deranged]

"...the very occasional winching duties..."

 

 

 

Winching draws a heck of a lot of juice!  It can run down even 2 batteries pretty quick.  Good to have a system in place that keeps your starting battery out of the winching loop... or be sure to leave the engine running at all times while winching.

[pawleyk]

 

"...the very occasional winching duties..."

 

 

 

Winching draws a heck of a lot of juice!  It can run down even 2 batteries pretty quick.  Good to have a system in place that keeps your starting battery out of the winching loop... or be sure to leave the engine running at all times while winching.

 

Shouldn't be an issue. I usually winch with the truck running, but with the system I'm planning the batteries will be disconnected from each other when the truck is off.