My water heater can be powered by electric or propane. When I'm off grid I usually use propane.That water heater is going to be a bugger.
I assume its electric
"Overkill" Solar Setup and Battery Bank for Camper
- Thread starter tmckenna
- Start date
John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
Well that is encouraging.
I would never want to run AC on batteries for 8 hours a day. It would be a very infrequent situation where maybe I'm low on propane for the generator and its a million degrees out so I'd run it for an hour or 2 before I went to sleep. Yeh I know it seems ridiculous to go through all this trouble for like a handful of actual situations or uses but my mind works in strange ways haha.
John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
Solar powered air conditioning in a RV is just a real tough problem.
To get the solar to feed your ac you have to park your tin can in the full sun which just makes the problem worse.
Yeh I have noticed its a bit of a sore subject. I wouldn't even necessarily plan to have the solar take the entire load of the AC, moreso just that it would prevent the batteries from draining in a very short period of time.
Seems like the thread got a bit off base. Lets forget the idea of using the AC off battery power.
Assuming I had 4 clusters of the Renogy 400w solar "kits", so 4 separate charge controllers, a large battery bank, and the 3000w renogy inverter. What do you guys suggest as far as wiring. I just want to make sure that the solar setups charge the batteries evenly, and that the inverter drains the batteries evenly.
Assuming I had 4 clusters of the Renogy 400w solar "kits", so 4 separate charge controllers, a large battery bank, and the 3000w renogy inverter. What do you guys suggest as far as wiring. I just want to make sure that the solar setups charge the batteries evenly, and that the inverter drains the batteries evenly.
John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
@ghostwriter66 had some good ideas that apply here.
The post was about shipping containers but should apply to an RV as well.
The trick is to insulate outside the metal envelope.
It makes me think of this
Just looking for suggestions for fuse placements, etc. I've never used a battery isolator and i dont know if it applies here, just looking for suggestions
John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
assuming this one https://www.renogy.com/3000w-12v-pure-sine-wave-inverter/
3000 ac watts / .85 conversion factor / 12 volts = 294.117647059 dc amps
294.117647059 dc amps * 1.25 fuse factor = 367.647058824 fuse amps
that means a 350 amp anl or class t fuse and 4/0 awg wire.
Assuming 105 Celsius rated wire and less than 20 feet round trip.
3000 ac watts / .85 conversion factor / 12 volts = 294.117647059 dc amps
294.117647059 dc amps * 1.25 fuse factor = 367.647058824 fuse amps
that means a 350 amp anl or class t fuse and 4/0 awg wire.
Assuming 105 Celsius rated wire and less than 20 feet round trip.
Thats just between the battery bank and the inverter correct? Should I do fuses anywhere else, and do I need any other hardware to ensure that multiple batteries charge evenly from multiple charge controllers?
The challenge of AC on solar becomes considerably less daunting if you forget about the low-effciency roof mounted unit that came on your RV and look into a small 20+ SEER mini split system. There are a number of examples of people running these systems successfully while boondocking.
I could be totally wrong but it doesnt seem like the SEER systems are all that much more efficient. The RV unit is 13500 BTU and pulls 1200w or so while running. A 12,000BTU SEER unit pulls about 1000w.
boondox
Chief Engineer, RedNeckTech Industries
- Joined
- Mar 1, 2020
- Messages
- 788
it isn't that it is a sore subject, at least not with me. It is just a significant engineering challenge and many don't understand just how difficult it is. Sounds like you are wrapping your head around that and figuring out where you want/need to go.
John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
Yes I am only referring to the master fuse and the master wires.
Yes you should do fuses elesewhere.
Time for a drawing.
No additional hardware is required to ensure multiple batteries are charged evenly by charge controllers.
You should look at wiring unlimited though.
section 3.3
Thats exactly what I'm doing. you guys have already helped me, and saved me a couple bucks regarding the 4kw inverter haha. Now I just need to figure out battery capacity and wiring.
beat you to the drawing
. Yes I know its a bit primitive but I'm at work right now so I just scribbled it really quick. So if I had 4 charge controllers the number of batteries doesnt affect their ability to charge evenly. If I wire everything in parallel to keep it 12v, the 4 solar chargers will charge any quantity of batteries evenly?I am just starting to dig into the complexities of this, but as I understand it, the mini-split systems use variable speed compressors and fans to match the AC output to the load. The unit may draw a lot of power when 1st cooling down a hot camper, but quickly drop to a fraction of that power draw as they continue to run.
