DIY Solar Charged Power Box

[Terrapod]

Before I start with this - A DISCLAIMER. I am not an electrical engineer. Nor do I claim to be one. This project is something I pieced together after reading a ton of information on cost effective solar systems and how to make one.

Anyone choosing to make this system does so at their own risk. Working with energized equipment can be dangerous. Please exercise caution when handling and using.

LASTLY: If you are not comfortable working with electricity - DO NOT ATTEMPT.



Over the years of building off road trailers I became more familiar with 12V systems. With those trailer builds I made compact, lightweight onboard power systems that worked amazingly well. From those systems I came up with the following portable power box. The reasoning for a separated self-charging system is - simplicity. When connected to the solar cells, this system keeps my 12V fridge running infinitely while keeping the battery topped off for overnight stops. FWIW - on its own, the 50Ah battery can keep the fridge running easily for up to 4-5 days (75 degree ambient).


PARTS NEEDED:

1. Plastic Ammo can or similar. - My source: https://www.amazon.com/gp/product/B004RDFOAC/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

2. 50 Ah LiFePO4 Battery with built in BMS - My Source:
Lithium Batteries

3. Genasun GV-10Li MPPT Charge Controller - My Source:
https://www.amazon.com/gp/product/B01N6AXQZH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

4. 100 Amp Mini Switch - My source:
https://www.amazon.com/gp/product/B0777QPFRD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

MISC PARTS VIA AMAZON:

5. 50 Amp Master Breaker
6. Qty 2 - 10 amp Blue Sea Breakers
7. 1 1/8" Panel mounted USB Charging socket
8. 1 1/8" Panel mounted 12V Power Socket
9. Heavy duty Velcro Strap (battery tie down)
10. Wire (6 AWG, 8 AWG, 10 AWG, and 12 AWG)
11. Wiring Connectors
12. Anderson plugs / connectors


TOOLS NEEDED:

1. Hole saw (1 1/8")
2. Soldering Iron, flux and solder
3. Wiring tool
4. Wire cutter / stripper
5. 13mm / 1/2" wrench
6. Rivet tool (optional)
7. Drill with various sized bits
8. Screw drivers (various sizes - flat & phillips)
9. LiFePO4 Specific AC to DC Charger - My source:
14.6V, 10A AC-to-DC Charger (Anderson) for 12V LiFePO4 Batteries (BPC- – Bioenno Power

SOLAR & POWER BOX WIRING DIAGRAM:

ASSEMBLY:

NOTES: This an abbreviated / basic assembly. Please review the diagram for more info.

1. Make sure the ammo can / storage bock you selected will fit the battery you have chosen.

2. Next - select the locations for USB charging socket and the 12V power. Drill the holes for each with the 1 1/8" hole saw.

3. Select the locations for the Blue Sea 10 amp breakers - drill those holes as well.

4. Select the locations for the Master Switch, Battery Coulometer face plate, and any last parts you wish on the outside.

5. Mount the Genasun charge controller and the negative bus.

6. Mount the battery. (NOTE: wiring was changed to 6AWG for future expansion purposes)

7. Cut hole for mounting the Anderson solar input plug and mount the connector

8. Wire the parts up. Being sure to not connect the battery until last. (Negative 1st, then positive).

NOTE: Please be sure to read any manuals supplied by the various parts. Namely the charge controller, battery meter, etc. Specific wiring may be required.


PHOTOS:

TOP

SIDE

INTERNAL VIEW

BOTTOM ONLY

ANDERSON PLUG INSIDE 4RUNNER

WIRING FROM SOLAR PANEL (HATCH)

 

[keller]

Nice system. I've bought all the bits for a more expansive system utilizing a DC to DC/MPPT solar charger and a permanently mounted battery. I was wondering if you had any pictures of how you mounted your panels.

 

[Terrapod]

Nice system. I've bought all the bits for a more expansive system utilizing a DC to DC/MPPT solar charger and a permanently mounted battery. I was wondering if you had any pictures of how you mounted your panels.

Sure.

 

[slprciv]

Great write up!

 

[Jetboy]

Looks good. One suggestion - I would not ground it to your vehicle unless you're intending to mix the two electrical systems. 12v systems do not need to be grounded for any safety reason and connecting this to your vehicle at best does nothing but risks the chance of some sort of issue between your stand alone battery system and your vehicle's electronics.

 

[Terrapod]

Looks good. One suggestion - I would not ground it to your vehicle unless you're intending to mix the two electrical systems. 12v systems do not need to be grounded for any safety reason and connecting this to your vehicle at best does nothing but risks the chance of some sort of issue between your stand alone battery system and your vehicle's electronics.

Great catch. Thanks!

Another version of this layout included a Redarc on-board DC-DC charger. I will remove that chassis ground.

 

[Terrapod]

May I ask you a question - What type of solar pv on your car?

If you are referring to Monocrystalline vs Polycrystalline panels, at this low level of amperage, it really doesn't matter. Get what fits your budget at this point.

My preference is Mono. They usually perform better in the heat and low light.

Hope that helps.