Using Deep-cycle battery, best way to charge off car.

[DanB.]

Hi,

I apologize if questions like this has been asked before. But I didn’t really find something that seemed to best answer the particular situation I am working on in my own small set up and car.

I have a Subaru outback and some accessories that runoff of a deep cycle battery that I can either charge using a standard wall charger or an 80 W solar panel.

Obviously and 80 W solar panel is a little bit problematic as I live in Washington state.

And as we all know sun can be a little unreliable and the trees. However the 80 W panel is fully capable of running my 50 W fridge cooler, and still supplying a little bit extra for charging the battery; but it would take an eternity in that setting. Also, can’t really use the panels while driving.

I used my 400wt inverter to charge of the wall charger, but that didn’t work and I had a repair to make...

So I am trying to determine a good and safe way to set up a battery isolation system where I can safely charge the deep cycle battery in the back of my car, without putting any risk on either the alternator or car battery and/or intern the deep cycle.

When I call places like camping world and auto-parts stores they seem thoroughly confused with the concept of what I’m trying to do. I know it can’t be that unheard of, I’ve seen it done in RV and where others are showing off rigs, both custom and etc

Probably longer winded than it needed to be but I would appreciate any expertise that anybody might have. if you have a recommendation of product, that would help.

 

[SquirrelZ]

A DC to DC charger sounds like a possible solution. You did say if you want a permanent install or something removable. Do a search on Amazon and you'll see a variety of options.

 

[Mighty Dodge Ram]

Head ”down” to the Power Systems forum, plenty of info there. FYI: I use an ArkPak 730 with a 105ah Marine SLA battery, charged by the alternator and solar while in the truck. Dometic offers the PLB 40 which is definitely applicable to your use. You’re only limited by the size of your wallet ??‍♂️

 

[F350joe]

Im building a system like this but with 4 gauge. http://campinnforum.com/community/threads/auxiliary-battery-for-refrigerator.4190/. My goal is to be able to remove the fridge and battery to put in a bear box.

 

[dreadlocks]

check out Victron's Orion DC Chargers, with a deep cycle your still in for a long drive to put a decent charge back into it.

 

[DanB.]

Thanks everyone so far for the information.

to answer the first question, I would prefer something permanently wired where I can just drop an extension cable in the back of my wagon’s trunk space where everything is set up.

Would something more like the image below possibly be more productive as an avenue to solve this problem. Using a battery separator circuit with built-in logic?

Forgive that it flipped sideways I am not sure why it did that when I uploaded it.

I will come through the “ Power systems“ thread and see if I can find something that seems to match a car set up rather than truck

 

[Buddha.]

The cheapest way would probably mirror what the truck guys do to add a second battery under the hood, except your second battery would be 2-3 times the distance from the main battery.

How to make a cheap isolated dual-battery setup for $50

So there are a lot of kits you can buy to have truly isolated dual-battery setups. Those are VERY NICE kits. They are also very expensive. I try and replicate those kits without spending as much money, while still having a similar level of quality and/or reliability. There are constantly...

expeditionportal.com

In addition you could add DC to DC charger which would be placed close to the auxiliary. It would probably improve the life expectancy of it somewhat. It may or may not be worth the extra expense.

12V 20A DC to DC On-Board Battery Charger

The best 12v battery charger. Free shipping. The DC-DC Battery Chargers are the most effective method to charge your home batteries from the starter battery

www.google.com

You could even add a DC to DC charger that incorporates a solar controller.

DCC50S 12V 50A DC-DC On-Board Battery Charger with MPPT

Introducing the RBC50D1S, harnessing MPPT solar charging and starter battery charging to provide rapid replenishment for house batteries. Equipped with multiple electronic protection mechanisms, it ensures optimal energy utilization without compromising the vehicle's starter battery.

www.google.com

 

[rayra]

seconding the $50 topic

How to make a cheap isolated dual-battery setup for $50

So there are a lot of kits you can buy to have truly isolated dual-battery setups. Those are VERY NICE kits. They are also very expensive. I try and replicate those kits without spending as much money, while still having a similar level of quality and/or reliability. There are constantly...

expeditionportal.com

.
Only reason to spend money on a DC-DC charger is if your vehicle's native DC charging system can't properly address an AGM / deep that needs a 14.6-14.7 charge voltage.
And if you are putting a solar controller in too, it's almost a surety that it will take care of the topping up. In which case you don't want a DC-DC charger at all, as your vehicle will readily put a bulk charge on any battery.