Powering a mini split
- Thread starter Brasher801
- Start date
This is what I have. I don’t have experience with it in the hot weather yet. I’ll post details when I do. But like others said, it’s highly dependent on insulation, size of rig, awnings, and other variables.
ultrakiev
New Member
- Joined
- Feb 25, 2021
- Messages
- 95
Look at the picture from the official brochure from ThermoKing. This is a very efficient DC electric air conditioner unit as well, condenser and evaporator are variable speed, compressor variable capacity as well. Envidia 8000 BTU . Batteries AGM 4pc 100AH @ 20Hr Nominal Capacity (Ah), 1246.2WH. Data provided in the chart taken and tested on semi-truck , so volume will be much lower than your RV but insulation will be lower as well.
It should give you a general idea.
It depends on your RV heat load. ( insulation thickness, number of windows, doors, etc)
In your case, Lithium chemistry should do a bit better job because on AGM if you run them at a higher C rating then less Watts you'll get. So lithium is the way to go because they don't have the same discharge curve as AGM, lithium curve is flat.
This unit from the brochure shuts down at 11.66V 20% battery SOC.
The way they calculated 360Ah total capacity I don't think it's accurate. They based on their rated capacity minus 20% . I think it will be even lower than 360Ah. Because they discharge at 40a 12v which will give them only 80AH of total capacity minus 20 %. But this is a different story ...
It should give you a general idea.
It depends on your RV heat load. ( insulation thickness, number of windows, doors, etc)
In your case, Lithium chemistry should do a bit better job because on AGM if you run them at a higher C rating then less Watts you'll get. So lithium is the way to go because they don't have the same discharge curve as AGM, lithium curve is flat.
This unit from the brochure shuts down at 11.66V 20% battery SOC.
The way they calculated 360Ah total capacity I don't think it's accurate. They based on their rated capacity minus 20% . I think it will be even lower than 360Ah. Because they discharge at 40a 12v which will give them only 80AH of total capacity minus 20 %. But this is a different story ...
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I presume that it would be more like 7500W / 19 = 468W per hour... A bit more, but perhaps still not enough.
I say 19 with the assumption that during the 5 hours of ~full~ Solar the batteries are just charging, 24 - 5 = 19.
Does that seem reasonable?
It seems to me, just thinking out loud, that the main questions to be answered are:
1) When the sun is *not* shining, can the battery bank sustain the overall power draw?
(Ideally, batteries could go to near near-depleted state without damage)
** The size of the battery bank could be derived from the answer to that question **
2) And when the sun is shining, can the solar panels fully recharge the battery bank, while sustaining the overall power draw?
(Worse-case: batteries start from a near-depleted state)
** The size of the solar array could be derived from the answer to that question **
Disclaimer:
I have *not* done this (yet), so the points above are just my assumptions (and you know what they say about assumptions!)
1) When the sun is *not* shining, can the battery bank sustain the overall power draw?
(Ideally, batteries could go to near near-depleted state without damage)
** The size of the battery bank could be derived from the answer to that question **
2) And when the sun is shining, can the solar panels fully recharge the battery bank, while sustaining the overall power draw?
(Worse-case: batteries start from a near-depleted state)
** The size of the solar array could be derived from the answer to that question **
Disclaimer:
I have *not* done this (yet), so the points above are just my assumptions (and you know what they say about assumptions!)
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MisterSandals
Participation Medalist
I would add that it must recharge batteries AND provide power used in #1).
iamrich
Solar Addict
I think I can get more than 5 hours most of the year. Even when the sun is low in the sky my 2k array is putting out 500w most of the time. Probably from 9-6 right now. I just ordered a 9k BTU AC for my work shop, so we'll see. I don't expect my little 6kwh battery pack to make it through the night running the AC, but I am hoping it will keep the room cool while I am there. After I build my house, I will have grid to fill in during the night, so no issues.
Yes, that's the implication... I will amend to make that clear.
Thanks!
Check out my graphs for Sunday through Today: https://vrm.victronenergy.com/installation/76892/share/d5bbdd04 ... 90F temps, full sun (today is supposed to get cloudy and stormy in the afternoon). My usual load is about 5kWh/day without the AC so the AC is adding another 10 or so.. and I'm able to produce enough to both run it and recover the batteries by 1pm (3.3kW solar, 27kWh battery).
Wow... That's a boat-load of power... Consumed & produced!
Generis
It'll be fun they said
Yes you can. I just put up a new thread on this. With your solar count, you should have no problems. I'm doing it 2 years now with under 1000w coming in.
Even had me in tears....Man I really sounded negative in that last message
iamrich
Solar Addict
link?
I just (literally) had a 9k btu unit delivered by FedEx just now. I probably won't get around to installing it this weekend, but I am pretty excited to be finally trying it. I know my battery/solar will not run it full time, but it might be just enough to keep me comfortable while I am in the workshop.
It's 109F here so far today, which is a break from yesterdays 118F.
The mini split in the living room has easily got the temps down to 73F, with about 20A going into the batteries as well.
Yesterday I got the living room down to 71F in the late afternoon and then turned the A/C off. It went back on each time the temp climbed back up to 78 - 79F, which only happened 3 times.
So far my FLA golf cart battery bank has had no problems with the load despite its great age and was still at about 58% capacity this morning.
The mini split in the living room has easily got the temps down to 73F, with about 20A going into the batteries as well.
Yesterday I got the living room down to 71F in the late afternoon and then turned the A/C off. It went back on each time the temp climbed back up to 78 - 79F, which only happened 3 times.
So far my FLA golf cart battery bank has had no problems with the load despite its great age and was still at about 58% capacity this morning.
Generis
It'll be fun they said
link?
I just (literally) had a 9k btu unit delivered by FedEx just now. I probably won't get around to installing it this weekend, but I am pretty excited to be finally trying it. I know my battery/solar will not run it full time, but it might be just enough to keep me comfortable while I am in the workshop.
YES: RV Solar/ Li/ and AC running full time
Hi, Everyone! I have been RVing for some years, and Solar powered stuff for some years, and Lithium powered for at least 15 years... and just finally got tired of all the people who complaining you CAN'T do your RV solar to run AC full time. Just drives me crazy. As you all know it's just...
diysolarforum.com
didnt work for me i am using 1k every hour with my 1200watt panel and 300useable AH on my SLA everstart 29dc MAXX maybe with a 400AH at 48volt LFP plus 5kw panels will be great
proper cap? are you refering to SUPER CAPS? do you have a good link for a 48 volt system????
Gearing up to try and run a 9k btu, mini-split from pioneer. Tried and failed without doing my research off a 200AH amperetime and 150w solar panel. New setup comes early-September in SoCal high desert (to cool 80sq ft bedroom):
- Solar array: 750-1000w of panel depending on what can be fit.
- Storage: 618AH SOK lithium running in parallel.
- Power: 2200w pure sine wave giandel inverter
- Mppt charge controller (any recommendations for better and priced under $500?): 40a rich solar mppt charge controller
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