General Idea
Our camper runs on a 12V electrical system using Lithium batteries for storage. These batteries are charged in two ways...
- While driving we have a battery-to-battery charger that uses the trucks 12V electrical system to charge the camper batteries. Some thoughts on this in the Hows and Whys below.
- A solar panel on the roof charges while there is sun.
Inside the truck basically all power is routed as 12V. There are a number of fuse boxes to protect long or high amperage runs of wire around the vehicle, but most stuff is centralized as close to the batteries as possible.
The one exception to "all power is routed as 12V" is our 120V system - which runs off of an inverter to power some outlets so we can charge things like laptops and the like.
Schematic
Some notes...
- The voltage/current meters have like 4 wires for power and sense, and each has a switch to fully turn it off. See the data sheet for these.
- Similarly, the pushbuttons used for the furnace/propane shutoff valve and the pump shutoff valve have more connections for the LEDs... see the data sheet.
- So the huge switches for disconnects... well we had the one on/off for when we did not have solar, then needed the 2 circuit one once we had it, but also wanted to disconnect the battery from the MPPT (not just the MPPT from the solar array) to prevent battery discharge when we store the camper for a long time... so I re-used the original large on/off that we had already. So yeah... bigger switches than needed... but they work?
Here is what the 4 way switch (C1) does...
Parts List
I tried to list the big ticket items first... two classes of stuff I left out:
- Crimps, bits and bobs. Lots of little things where it does not make a difference what you get. Need to splice 2 cables together? Solder and HeatShrink, or use some crimp terminals for the correct size... pick what you like. Does not really make a difference.
- Wires - or at least the details for any of it. You should derate wires to your own comfort level - good starting tables are everywhere (Try googling for "AWG ampacity chart" and looking at images.) Your electrical current needs will dictate sizing. Please know what you are doing before doing this! Read up and stay alive.
- Fridge, pump, and furnace. You can see more about the furnace here, but generally get something that works. For reference, the pump we used was the SHURFLO 4008-101-E65 3.0, while the fridge is a ARB 10801472 Fridge Freezer Series II 50 Quart. Our furnace is the Dometic™ (Atwood) DFSD12111 (for which you also need to buy a door assembly to cover the outside...).
| Ref | Group | Thing | Notes |
|---|---|---|---|
| A | Batteries | 2x Battle Born LiFePO4 100Ah 12v | So total of 200Ah in the truck. Sooo expensive... but light and nice capacity and easy to work with/use. |
| B1 | Protection | 3x Terminal Fuses | These mount into the "Terminal Fuse Holder". The big fuses of the system - used on each battery and the inverter input. |
| B2 | Protection | 3x Terminal Fuse Holder | As written on tin. |
| C1 | Switches/Buttons | Blue Sea Systems - Battery Switch ON/Off AFD | Disconnects EVERYTHING from the battery - for storage or emergency. |
| C2 | Switches/Buttons | Blue Sea Systems - Battery Switch ON/Off AFD | Disconnects Solar from the MPPT for storage |
| D | Other | 2x 100 Amp Mini BusBar | Makes distributing from the battery easier. We got the linked ones - there are a bunch of variations and they are basically the same. |
| E | Protection | 2x Blue Sea Systems 7035 187 Series Resettable DC Breaker | I used these where I expected there may be more issues than other places, and didn't want to keep changing fuses. Resettable is great, but they are big an expensive compared to a simple fuse. |
| F | Batteries | Sterling Pro Batt Ultra Battery to Battery Charger | Charges camper from truck. A bit nicer than just the diode devices they sell - nicer on the truck alternator, and a smoother charge profile for the batteries. |
| G | Other | Power Inverter Pure Sine Wave 1200Watt 12V DC to 110V 120V | Pure sine wave - more expensive but likely to place nicer with most devices you plug in. Some of the cheaper ones basically output a square wave with makes some devices unhappy. The one we got came with a control panel thing you can mount remotely which was great (well and one of the reasons we got this one). |
| H | Solar | Victron Energy BlueSolar MPPT 100/30 Charge Controller | The actual power electronics that converts the solar panel output to what the battery needs. MPPT instead of PWM since we will get more power. Tradeoff being more complex internal electronics and more money. |
| I/td> | Solar | Victron Energy MPPT Control | Wanted something to mount in a nice place for seeing status and controlling the solar system. Cable sold separately - jerks. |
| J | Other | 3x LCD Display Digital Current Voltage Power Energy Meter | These are fairly low cost (and not super accurate). Mainly got these since they would mount nicely in the truck, and show current/voltage. Also key - they have a backlight that can be turned off! Gotta save those mA... |
| K | Switches/Buttons | (many)x 2pin Round Toggle SPST Switch | Found these in a bag of 6... otherwise lots of options here. Used for turning off USB ports, the radio, small displays, and stuff like that. |
| L | Protection | 2x Automotive Fuse Block | Basically everything is fused - this just holds fuses in a nice place. There is one in the main electrical area, and one up in the kitchen. |
| M | Other | 2x Dual USB Charger Socket | Just get something that will run on 12V... lots of options, these have worked well. |
| N | Switches/Buttons | 2x Ulincos Latching Pushbutton Switch U19C2 (One red, one blue, link is for red one.) | They sell a pigtail socket thing (NOT FIT U19D1) to make connecting to the back easier. Went with the lighted switches to make sure I did not leave these devices on by accident. |
| - | Solar | Renogy 200 Watt 12 Volt Monocrystalline Solar Panel | There are about a 1000 pages of pros and cons for different solar types. I wanted rigid (vs flexible) for increased durability, and so I can have some airflow under the panels to help cool them in summer. 12V will allow me to series more panels if needed. Monocrystalline? Hoping more power for the size means I don't need to series another panel. Tradeoff as usual is... cost. |
How's and Whys
- Lithium batteries are light and high capacity for the size/weight. So that's why. They are so expensive... leave them in your amazon cart, then one night after drinking a bunch order them while your decision making is impaired.
- Generally I added resettable fuses to harness runs that traveled a long way or that I was unsure about. For instance look at the 12V fuse block that runs the "kitchen" and furnace area - this has a resettable fuse located near the power source, while the other fuse block (which is located adjacent to the bus bars) has no resettable fuse.
- The 12V fuse blocks both route grounds thru the same sense - that's why it looks a bit odd. In this way we measure all the 12V stuff on the same meter.
- On the subject of meters - these are setup to measure 12V power usage, battery charged from the truck, and inverter power. Solar stuff is measured with the MPPT controller panel, so I didn't add another meter just for that.
- The batteries are the "single point ground" - because of this the current sensors are all on the low side.
Pictures
<working on it>
No comments:
Post a Comment