House Battery Set up - Brief Explanation

Not an in-depth write up, but some folks have asked about the basic for a dual battery set up. I'm not an electrician, so if you burn down or melt your truck....that's on you.

I wanted a house battery for the weeks I'm up at camp pretending to hunt. I initially had a solar generator, which worked, but I still wanted to have an actual second battery in the truck. If you're looking at a solar generator, Pecron makes some of the best tested ones out there and they're super affordable. The purpose of the set up is to draw only on the house battery without killing your starter battery, all while charging your house battery via the alternator when running.

There are 2 set up types you can run on the truck...those being an AGM/lead acid battery or a Lithium. My advice, go Lithium and buy a decent one. Many folks have great reviews on cheap Amazon batteries, such as Chin. Some like the super expensive Battleborn. More amp hours to use and quicker charging among other benefits.

For my first set up, I bought the 1st Gen Auxiliary Battery Tray Kit from f-er.com. You can also fab your own, but this kit is really nice and thought out. I next purchased a Group 27 AGM battery. The install was pretty straight forward with the directions. Well...now what?

I grounded the second battery properly and ordered a simple isolator. Keyline has a nice kit for cheap, which includes almost everything you need. In addition to the kit, I needed fuses. I prefer actual fuse breakers over standard fuses. They trip when there's a fault and you can manually open them if you need to work on the system and want to not have power going to your outlets. I ran wiring to the bed of the truck for a single 12v outlet I had for the fridge...nice and simple. I don't have any pics of that set up, but mounted the isolator against the firewall. It has a small ground lead with it, that I grounded where the rear block is grounded. Pic below.

After one trip, I decided I wanted to go to Lithium for extra usable amp hours. The challenge is that your car battery doesn't play well with Lithium, so the simple isolator won't work. I ordered a Redarc Alpha DC to DC charger. These have Bluetooth and a solar MPPT built in and also serve as an isolator. It also has a function to back flow a charge and add juice to your starter battery, in case that takes a sh!t. Initially, I thought 50A, but decided the 25A would be fine for the battery size. The charge will use 25A to charge from either solar, alternator or a combination of both. Speaking of solar, I have a permanent hood panel coming for the truck. It will be wired to the charger to be able to charge as I mentioned above. I also installed the solar leads using plugs, so I can also attach a larger portable panel when I'm parked to charge the battery faster and with the truck off. The hood panel is 95w and from Cascadia4x4. Far better construction than the Lensun panels. My portable panel is a 330w Pecron suitcase panel. For the battery I chose the Epoch 105ah, which fits perfectly into the F-er battery tray. It has Bluetooth to monitor it, as well as its self heating, as Lithiums don't like to charge at colder temps. This time around, I also added a negative and positive bus bar for management. I don't have enough use requirements to add an actual fuse box in the bed or go full on Redarc management, but I ran an extra 2 12v outlets, as well as a dedicated ARB lock-in fridge outlet. All of those leads are fused at the positive bus bar. I could have run a single hot lead back to a Bluesea fuse box, which would have been smart as you can easily add more outlets. I'm not smart, so I ran the 3 leads separately. I also still have my Pecron solar generator for back up and to use outside of the truck. I charge that during the say with a small 100w Pecron suitcase panel. I did not run any sort of battery monitor. The Epoch and Redarc items have Bluetooth and apps. I can monitor status and charging from the iPad in the truck.

Some keys:

• Run your wire to accept the max amperage you may expect. Larger is better than smaller and won't light your truck on fire.
• Fuse it properly according to what you'll be running. As above, the fuse should pop before your wire overheats.
• Put your fuses close to the battery, not somewhere down the line.
• Crimp and heat shrink your connections.
• Buy once cry once. Go Lithium, well Lithium iron phosphate (Lifepo).
• Amps = Watts/Volts <----- Math...I know, right???

The battery tray from F-er


The Keyline isolator kit


Keyline install location


The fuse/breakers I used


Wire size reference chart


The basic isolator set up


Battleborn, Epoch and Chins


Here's the current set up. Not the cleanest wiring but it is what it is. After this upcoming season, I'll decide whether I want to add an inverter. If that happens, I'll do a complete Redarc Manager 30 set up on a panel in the bed with the inverter. That'll be a whole rewire with a bigger battery for the inverter. I'll likely save that for my new truck I'll be buying when I retire in a few years.

 

For the next truck I'll do a cleaner Redarc set up...take my time...go bigger and have the battery in the bed. I mean...look how happy that dude looks. Renogy makes good stuff, Victron makes better stuff, Redarc makes the best stuff. Definitely my opinion only, but I did a deep dive and looked at some set ups my buddies have. I look at it like Ranchos vs Kings. Both will work but...

 

Lithium doesnt have problems in the engine bay? How long ago did you do that? Nice setup.

 

One more and I'll shut up. AGM/LA vs Lithium.

Lithium batteries are considerable lighter than AGM batteries. They are far more energy dense. I can use, if need be, the majority of my amp hours on my Lithium. You can only use about 50% of an AGM. They charge faster and more efficiently. They have a much longer lifespan when it comes to draw down.

 

No issues with it in the bay. I've been running it for about 2 months or so. As I was typing this, I thought about possibly moving everything to the bed and using the bigger battery. I have a 300ah Epoch already. I know myself though and that will likely lead me to doing the full set up in this truck. I have zero self control.

The 300ah is a tiny bit too big to fit in the F-er tray, but should fit nicely in the spot just in front of the wheel well in the bed. I have the drawewr system and can probably attach the battery box to that. Hmmmmmmmmmm damnit.

 

To properly charge your LiFePo battery you need a DC-to-DC charger -- that's how it's done in RVs and boats. The alternator won't fully charge LiFePo because its made to charge lead acid batteries which operate at a lower voltage and have a different charge profile. In basic terms, the alternator begins tapering off the charge too early, so the LiFePo never gets fully charged.

It's explained pretty well here but there's no shortage of info elsewhere online: https://www.aaeac.com.au/dcdc-charg...r vehicle has,batteries, but it's not crucial.