Home built 12v battery box

[CMARJEEP]

After looking at some of the pre made power stations I decided to build my own. None of the big brand power stations like Jackery or Ecoflow had the plugs I needed and I also don’t need 120v outlets.

Parts list:

• Weize 50ah LiFePO4 battery. I chose this out of the cheaper Chinese brands because it has good reviews and also comes with low temp charging protection which most others in this price range don’t have.
• Apache 2700 case from Harbor Freight.
• Victron MPPT 75/15 smart solar charge controller.
• Victron SmartShunt 500a to monitor battery charge percentage and power draw.
• Powerwerx DC to DC charger to charge while driving off the alternator. Decided to go with this one instead of Victron due to size. The Victron charger was more power than I needed and much larger. The Powerwerx is simple and provides 2, 4 and 8 amp charging options.
• Blue Sea 6 fuse panel with negative.
• Blue Sea 50a breaker
• Powerwerx dual 45a Anderson flush mount plug. One is used for solar and DC to DC in. One is used for two 30a outputs.
• Blue Sea 12v cig plug.
• Blue Sea dual USB plug.
• ARB locking 12v plug for the fridge.

The battery is held down with industrial Velcro plus the strap. The rest of the components are all mounted with 3m VHBtape. I wanted to limit the amount of holes drilled in the case as much as possible.

As far as battery life- the main purpose of this is to power my Dometic CFX28. I have been able to get 2-3 days out of the battery depending on outside temperatures without any charging. I have a Renogy 50w folding solar panel that will allow me to go pretty much indefinitely.

I have taken this on a few trips already and it has been working great. It provides more than enough power for me. Besides keeping the fridge cool I’ve used it to keep all my devices charged up and pump up my paddle board with a 12v pump. I was just on a 4 day trip where it was about 80 during the day and 40’s at night and the fridge and other charging of devices used about 30% a day. Putting the 50w panel out in the morning and it got me back up to 100% by lunch.

 

[dstefan]

Very nicely done! I don’t get why so few people do this vs the Jackeries, etc. I ended up with something similar but paid National Luna for their DC DC Powerpack out of laziness and having not much DC electrical experience. I’ve loved it with a Battleborn 100AH inside.

In the end I did plenty of other DC wiring for the rest of my build, so If I was to do another setup, I’d definitely build my own. Think more people should do it.

 

[givemethewillys]

Nice, I like it! I didnt price out all of the components on your list - did you save a lot compared to a pre-made one?

 

[jmnielsen]

Looks great! Interested in what you spent on it as well. I bought cheapo unit from amazon to get by for a couple trips, but would like to put something else together at some point.

 

[CMARJEEP]

I think I’m into it about $600ish in the individual components. I did not save money compared to buying a pre made one with similar output. However, this is modular and easily repairable. If something breaks I can easily fix it. If the battery goes bad I can just plop a new one in. It’s pretty much water and air tight so it can get wet and dusty. If down the road I need a different plug I can swap them out. I already ordered a new usb port with high output USB C so I can charge my laptop.

All the wiring is high quality Anchor wire with heat shrink connectors.

I went with Victron and Blue Sea stuff which carries a premium. I think you could get by doing it a lot cheaper and you could save on stuff like the charge controller. Also the smart shunt wasn’t absolutely necessary and was expensive but I wanted to be able to monitor the battery closely. You could use a volt meter to keep an eye on charge level, although that’s harder with these LiFePO4 batteries. Also instead of the fuse block you could just use inline fuses on the individual components. Instead of the main breaker you could use a fuse.

 

[robgendreau]

How about heat in there? or do you just charge, use solar, etc with it open?

 

[Hnoroian]

Nice components. Nov ‘22 I got the same battery and have used it quite a bit. It does what it should. The price was right too then. Similar configuration minus the dc/dc charger. I am a fan of the Apache line up but opted for a pelican vault v250 as it is a top loading case and I use it as a seat and step. It also fits nicely in footwells. I also have slim led marker lights for a simple flood.

 

[CMARJEEP]

Heat is not an issue and I charge and use it closed up. Another reason I opted for no inverter and keeping it 12v only. The DC to DC gets slightly warm and the solar charge controller doesn’t get warm at all with how small my panel is.