Changes to my build after this summer/fall of usage

willo

Solar Addict
Joined
Apr 8, 2020
Messages
389
Allrighty, I've been making changes to my rig after using it all summer/fall. I figured this may be handy for anyone going the big camper solar route.
My rig is a 37 foot Montana High Country 5th wheel camper. I'll try to keep this all electrically related for the moment.

The house battery:
My original house battery tanked in the last 60 days or so, then it murdered my original 24/12 converter. It wasn't really supposed to be charging a battery anyway so I'm calling that one my fault. I've now chopped out the original battery and replaced it with a small SLA cell and a 'break away battery charger' which is a small charge controller that's all of $5. I would worry about parasitic load, but it's only fed when my truck is connected to the trailer.

Upgraded 24/12 converter:
I got the 70a 12v converter to make sure I can handle the surge motor loads from my leveling system and my slide out motors. It works just fine. I also love the bolt terminals vs the spade terminals of the 40a.

Battery capacity:
I'm upgrading it. My original Tesla module still works fine, but I'm swapping it out for 15kwh of LifePO4. With the working voltages of the 5kwh Tesla module, it was more like a 3Kwh pack. The new pack - 16x 280ah LifePO4 cells should provide an amazing amount of power for my needs. Also, I will rest easier - I blew out a tire on the interstate. It was smoking like mad, I thought the tesla module had gone up at first! I'm leaning toward tearing apart the tesla for an ebike build.

Battery heater:
Most of the time, I had no need of this. But I was camping in Colorado in November, and the pack was getting too cold to charge. By time it had warmed enough during the day, I'd lost several hours of solar charing time. It turns out that we like winter camping - nobody is around! An so, I'm adding a warming system to my batteries in the new pack build.

Inverter:
I started out using an inexpensive 18v converter - the working voltage is ok with the Tesla pack. In testing it couldn't get my smaller A/C going and I just didn't like the exposed wiring terminals on the side of it. Now I've built in a Mulitplus 3000/24 and I love it. I really could have used the hybrid operation this summer when I had a sensitive 15a circuit. Every time I'm down in the storage lot working, I have readily available AC power, which is wonderful.

Cut off solenoid changes:
This was a catch-22 of my own making.
Originally I used a 12v solenoid to cut on/off all my 24v discharge sources. After killing the 12v battery, I had to get stupid with some channel locks to jump start the system. I've now swapped it out for a 24v solenoid that runs directly from the battery back (and uses my solar controller relay output) It's simple and reliable. I'm also adding a bypass switch with pre-charge resistor in case. If the solenoid were to fail, I could be SOL when traveling. By adding a battery cut off switch in parallel, I can manually over-ride the solenoid.

Internal inverter control:
After adding the Victron Multiplus when I was down in Texas, I wanted some extra controls in the camper so I don't have to get into the electrical bay as much. I opted for the expensive, but nice Victron panel. It'll allow me to tune the hybrid mode, control the inverter, and view the operation state. Expensive at $130 but worth it IMO.

More fuse panels:
I had added a 12v sub fuse panel before, but now I've added a 24v panel too. It turns out that the amazon cheapie I am using works at up to 32v for the LED fuse status indicator. I don't know that I trust them at 30a on a circuit, but for less than that, they seem fine.

Fridge power:
I also have a 12/24v compressor Dometic freezer/fridge cooler. It works GREAT - I used it to bring a bunch of fish back from Texas. I added a simple outlet connector in my basement bay so I can easily plug it in. (note to self, add the external outlet for use when at camp sites...)

Vehicle charging:
Some discussions here got me thinking and I determined I'd like to have an extra charge source on long drives/tows to feed the pack. I'm adding an isolated 12/24-10a victron charger to cover this. I did tow on some rainy days and didn't get much charge from solar only. I think this'll let me off-grid a bit more, which would be great.

Improved 12v cut-off:
The built in 12v cut-off is apparently only partially effective. My house battery was dying regularly before I got the solar going. Afterward, it was clear that there's some parasitic drain there. I'm going to re-purpose my 12v solenoid as an improved 12v cutoff, with controls up in the camper. Now that the house battery and brake power is separated out, I see this being feasible.

Raspberry PI GX:
I'm still not sure if this is worth it for me. I have a smart solar, Multiplus, BMV-712. By the time I purchased the three USB dongles and the PI, I'm already at $150. An actual GX is around 300. Anyway, I have all the bits, so it's happening. I still have to extend a cable for the BMV interface, but that's easy enough. From there, with my internet PI, I can use the victron portal. I'm going to add something to run a graphana instance and have better off-grid data I suppose.
I did add a 24v-5v converter to power the PI, which is nice and gets it off the converter side. OK, I'm a total nerd, the data will be fun to work with. Also, this is prep for my future sailing setup so I'm all about the data, reliability and figuring out what works best for me.

Sooo, yeah. During year one I did a ton of work, learned a few things and was very happy. The only road mod was to do some janky 12v wiring for my cooler. It was reliable and worked great. I got stuck on the side of the road and had some power resources but REALLY wished for A/C that day as it took 4-5 hours for roadside assistance to show up and help me out. My new mods should make it even better, and allow me to do some extended boon docking on travel days.
 

HRTKD

Boondocker
Joined
Apr 24, 2020
Messages
6,535
Location
Somewhere South of Denver
Battery heater:
Most of the time, I had no need of this. But I was camping in Colorado in November, and the pack was getting too cold to charge. By time it had warmed enough during the day, I'd lost several hours of solar charing time. It turns out that we like winter camping - nobody is around! An so, I'm adding a warming system to my batteries in the new pack build.

November in Colorado is going to be a little chilly, especially in the mountains. It was well below zero F for me in October at 9000' elevation.

I take it that your batteries are not in an interior compartment that gets heat?
 

willo

Solar Addict
Joined
Apr 8, 2020
Messages
389
My batteries live in the unheated front 'garage' under the bedroom. Also, I plan to leave the charging system on all the time, so they'll need electric heat if some form.
 

willo

Solar Addict
Joined
Apr 8, 2020
Messages
389
After running my victron imaged raspberry pi, I've determined that I love having it. It's trivial to keep track of my system status.
I just need to figure out how to add some custom data to it.
 

willo

Solar Addict
Joined
Apr 8, 2020
Messages
389
Today's mods - The other day I added a new 24v-5v converter to my victron pi the other day. Today I extended that to my internet pi system. Now I can keep those systems up with the inverter shut down. I'm thinking of adding a dedicated cutoff for my monitor/internet to keep them up when everything else is shut down. My tesla cutoff is 19v, maybe crank that up to 19.5v and kill the pi's at 19.
I also added my inverter control panel to the cabin. It's nice to remove that 10-13w 24x7 load.

I'm now testing support of my dometic CFX95 fridge freezer as a constant load. I think I'm going to want to have my new battery in place for serious use but right now having pizza in there for camper work would be nice.
Once I migrate to the new battery I'll see if I can run it on pure 24v and turn off my 24/12v converter as needed.
 

bdbugbee

Solar Addict
Joined
Mar 26, 2020
Messages
118
Today's mods - The other day I added a new 24v-5v converter to my victron pi the other day. Today I extended that to my internet pi system. Now I can keep those systems up with the inverter shut down. I'm thinking of adding a dedicated cutoff for my monitor/internet to keep them up when everything else is shut down. My tesla cutoff is 19v, maybe crank that up to 19.5v and kill the pi's at 19.
I also added my inverter control panel to the cabin. It's nice to remove that 10-13w 24x7 load.

I'm now testing support of my dometic CFX95 fridge freezer as a constant load. I think I'm going to want to have my new battery in place for serious use but right now having pizza in there for camper work would be nice.
Once I migrate to the new battery I'll see if I can run it on pure 24v and turn off my 24/12v converter as needed.
There is a Bluetooth dongle that you can add to the Multiplus to access the Multiplus On/Inverter Only/Charger Only/Off switch and the AC input current limit via Victron Connect on your smart phone. Less expensive than the dedicated control panel.
 

willo

Solar Addict
Joined
Apr 8, 2020
Messages
389
There is a Bluetooth dongle that you can add to the Multiplus to access the Multiplus On/Inverter Only/Charger Only/Off switch and the AC input current limit via Victron Connect on your smart phone. Less expensive than the dedicated control panel.
I actually have one, but I had to pick up the mk3 interface in order to actually program the multiplus.
The app is nice, but certain family members are technologically... challenged.
 
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