Modular Power Tower (200ah of lightning in a box)

So I got real bored one day and started looking at ways to improve my camping experiences. I figured I'd start using the truck to do some overlanding type camping, and figured I'd get the ball rolling by upgrading my power supply.

I present to you, the MPT, a home brew system I'm designing to make camping in every season that much more enjoyable. I started last year by buying a chinese diesel heater, I did a bunch of research, figured out a way to put it in the garage (thru-door exhaust/intake, mounted to the door directly) so I could work out there during the winter without using propane - since that is my main source of fuel for my generator.

Anyway, fast forward to the late winter/early spring time frame, I decided I was going to make an overlanding CDH and I was looking for various boxes and ways of mounting it to the truck, etc. My original plans were bed bars, a rigid top RTT, and then utilizing the CDH to keep the RTT warm or an inline fan to keep it cool, etc. I picked up a 2kw heater to use for my winter camping solution and landed on the RIDGID 2.0 Pro Gear modular tool storage box to house it.

I did a rough mount of the CDH in the box (this one), figured out a way to fit a fuel tank for kerosene, and a 30-50ah battery in there - the plan on that is to have a little MPPT and use either my folding panel, or pick up a dedicated smaller amp panel to feed the internal battery so the CDH can act as a standalone unit.

While doing that, I also figured it would be real nice to have a way to externally power the CDH, just in case it was needed for multiple days. A bigger power box was a design requirement then, and I landed quickly on a set of outputs that I would need to power the CDH, alongside everything else I could think of needing power at camp.

Quick mockup, lightning box on the bottom, CDH in the middle, spare box for supplies on top.




The idea was that the power box would have heavy duty SAE inputs for solar and DC, and in turn have outputs for USB/USB-C, Automotive 12v, 12v DC barrel jacks for the Trailwash system I built, and a direct SAE output to power the CDH remotely (among other things).

Anyway, all of that is a long winded way of saying that I made a real neat power box and someone asked for the parts list, so here it is.

Be gentle, it's still not completely buttoned up, but it's nearly iteratively complete.



Power box base
Renogy Solar MPPT/DC Charger

$414 WEIZE 12V 100Ah LiFePO4 Lithium Battery, Upgrade Mini Size & Lightweight, 100A Smart BMS, Deep Cycle Low Temperature Protection Battery for RV, Solar, Marine, Trolling Motor (2 Packs)

Weize LifePO4 Mini 100ah batteries
BougeRV 200w flexible solar panels

$30 iGreely Solar Panel Connector Cable,10AWG SAE to Male & Female Adapter PV Extension Cable Wire for RV Solar Panel DC Power Battery Charger with SAE Polarity Reverse Adapter 3.1M/10Ft Black

Sleeved MC4 to SAE solar panel cables

Billion wealth 10AWG 2FT Pure Copper SAE Connector Power Socket SAE Power Socket Sidewall Port Connector with Fuse for Solar Generator Battery Charger

SAE Inputs/Outputs

$30 Mofeez Power Distribution Block Bus Bar, 4 x 3/8" Posts, 6 x #8 Screws Terminals, Max 48V 250A (Pair, Red & Black)

BUSS Bars

$12 Ampper Battery Switch, 12-48 V Battery Power Cut Master Switch Disconnect Isolator for Car, Vehicle, RV and Boat (On/Off)

Master Disconnect

$25 USB C Car Charger Socket 12V USB Outlet 2 Pack,78W RV USB Outlet Dual 30W PD USB-C and 18W QC3.0 Car USB Port with Button Switch Waterproof for Car RV Boat Marine Truck Motorcycle ect

USB/USB-C outlets

$9 Cigarette Lighter Socket - Car Marine Motorcycle ATV RV Lighter Socket Power Outlet Socket Receptacle 12V Waterproof Plug(2 Pack)

Automotive outlets

$7 Maxmoral 3PCS DC-099 DC Power Socket Connector with Waterproof Cover Cap,Threaded Female Panel Mounting Adapter Power Jack 5.5 x 2.1mm

DC barrel jacks

$10 Nilight 5 Gang 3 Pin Rocker Switch Panel Waterproof On Off 12V Red Toggle for Cars Trucks Boats

Switch bank

$35 WUPP 12V Fuse Block with Relay, Automotive 6 Circuits Fuse and Relay Box With ACC Interface, Universal Fuse Block and Relay Kit for Cars Trucks Marine Boat

Fuse box with relay driven switches

$10 Uenhoy 2 Pcs Stainless Steel Air Vents 4" Round Soffit Vents Louver Grille Cover Wall Vent Cover with Screen Mesh for Kitchen, Bathroom, Office

Stainless louver vents with steel screens to prevent rodent intrusion



So the idea is that each outlet is on a single fused switch, so the first two switches control the two USB/USB-C outlets, the second two the automotive outlets, the last one controls the two barrel jacks, which are jumped at the switch but are fused separately in the fuse box, and finally the direct SAE output is fused inline and is hot while the master disconnect is connected as it runs directly off the positive buss.



I was trying to take advantage of the space by sticking a louvre vent directly behind the Renogy charger, but standing it off so there was space between the box and the vent, and then adding the vent on the other side. I figured it would allow for a little convection action and let the heatsink pull air in as it rose to the top of the box. The batteries are wired in parallel and connect to the ground buss directly, and to a master disconnect, then buss on the positive side. Please don't judge the current battery stack retention, I'm working on a way better solution in my head.



The way the charger is designed, it will allow for solar only, solar + DC in which case it rate limits each leg to 25a total, or DC only at 25a. I set up the inputs so that the top two connect to the solar leg, and the bottom one connects to the DC leg. I can use the DC leg on the way to camp and I can use the solar inputs when I'm at camp.



The two panels, lying flat on the ground, produced the below at 2pm EST in Ohio when the sun couldn't make up its mind if it wanted to be out or behind clouds. It took about 8 hours to pump 85ahs into the stack of batteries, from 8am to 4pm when I noticed it showed as complete.





Here's a super rough non professional, just for my own head to remember the design, circuit diagram that is absolutely not an actual circuit diagram by any means. Please stop judging it.

 

Nice. Mine's just an old ammo can. No room for an inverter?

 

I am putting the bougie into getting my 4.5 year old interested in camping and future-proofing that concept with a little ingenuity. But on the topic of the inverter, I did briefly consider putting it inside the box, wiring its own set of terminals and adding an external outlet ... I did. I really did. And then I just thought, with the way the batteries are oriented in the box, I could just stuff my inverter into the box and hook up alligator clips if I ever needed it. An inverter isn't something I've regularly used while camping. Hell, even when I was using a CPAP regularly, I got a step-up for it that made 18v from two 12v legs (which is mostly the reason I added two barrels, just in case), just to avoid having to convert power from 12v to 120v back to 18v and all the conversion losses that followed.

 

Fair. Though with my setup I can run an induction hot plate, which gets rid of one more consumable.