If you are off grid and have 2 x 80 watt solar panels, how long would they run an a/c for?
I guess there are lots of variables but you know what I mean.
(I don't have a van yet and would be pretty frugal if I did use an a/c)
Cheers
Bobdown said
05:51 PM Jan 23, 2022
NoelB wrote:
Hi. Probably a question for the techies:
If you are off grid and have 2 x 80 watt solar panels, how long would they run an a/c for?
I guess there are lots of variables but you know what I mean.
(I don't have a van yet and would be pretty frugal if I did use an a/c)
Cheers
Hi Noel,
About a minute for the aircon if you could get it started.........
You need to read up on the solar power section and a big inverter that would drain your batteries real quick.
If you are off grid, a 12v fan is about all you need, but the experts will be along soon to tell your how much solar and battery you need, and I mean that in a nice way.
Cheers Bob
erad said
06:00 PM Jan 23, 2022
Of course there are a lot of variables, but in general, you can multiply the installed capacity of your solar panels by 5 to get the energy storage for one day's generation. You need batteries as well. So, your 2 x 80 Watt panels will generate about (5 x 160) = 800 Watt-hours of energy. A small aircon will pull maybe 800 watts so you could run the aircon for 1 hour, assuming that you ran the batteries totally flat. Not really a feasible proposition....
Peter_n_Margaret said
06:24 PM Jan 23, 2022
Numerous people doing it.
The smallest Mitsubishi Heavy Industries inverter A/C is the choice for off grid use.
You will need at least 1,000W of solar plus about 400Ah of lithium batteries to get a decent run time.
Cheers,
Peter
yobarr said
06:28 PM Jan 23, 2022
NoelB wrote:
Hi. Probably a question for the techies:
If you are off grid and have 2 x 80 watt solar panels, how long would they run an a/c for?
I guess there are lots of variables but you know what I mean.
(I don't have a van yet and would be pretty frugal if I did use an a/c)
Cheers
Hi Noel.Please note that I know little about how an AC uses power,or how much is used,but when I started looking in to a Solar powered AC for my van to handle the high temperature when free camping up around the Kimberley,I was told that it couldn't be done! Anyway,I installed 1650 watts of polycrystalline panels and 540ah of Lithium batteries through a 5kw Victron inverter so I can run my Mitsubishi Heavy Industries 2.5kw AC system 24/7.Keeps my 6 metre van cool and believe me,when it's 45 degrees outside,and even hotter in the van,it is a Godsend! Everything in the van is electric,except my diesel heater,so I have no need to carry any gas bottles.There are several members here who have vast knowledge of how the numbers work,but I am not one of them! All I know is that my solar-expert mate says that the solar capacity should me a minimum of 1.5 times the battery capacity.Others may dispute this,but as I have no knowledge of this stuff,I can't comment.All I can say is that my system works for me! Although I am on the road permanently,and do not use van parks (saving at least $10,000/year) I have never run out of power.Works for me.Good luck with your research, but a word of warning! Solar panels are definitely a product where you should never buy El Cheapo.Won't perform well,and won't last.False economy. Cheers.
NoelB said
11:06 AM Jan 24, 2022
Thanks all. I am definitely the sort who flicks a fans on instead of reaching for the a/c switch.
Unless I'm in a caravan park on power!
Cheers
Bicyclecamper said
12:03 PM Jan 24, 2022
You can get 12 volt unots, both from the US and China, I do think now you can buy them here. As an friend. had one ordered from China sent to my address in Autumn last year so he could fit it to his 4wd Homebuilt motorhome. It was an 4 ducted unit, but he only used 3 and blanked off the 4 th one. I have been in touch with him and it is still working real well. It has an outside condenser with a fan, After he fitted it, he turned it on on a 30 C day, and it was down to 22 C in only half an hour. His batteries are 240 ah Lithium, and 800 watts of panels. He did say he is fitting another 120 ah battery, but has enough solar. The AC cost him $1600 delivered , so not cheap, but the US models delivered to OZ, was going to be $3000.
Whenarewethere said
01:31 PM Jan 24, 2022
As others have said 2 x 80 watts is not enough.
By a long shot.
But.
If you use a 2.5kW split system & not the rubbish the the caravan installers are still using from last century. Use it on an economical setting & use it more for reducing humidity, it will work on reasonably well sized setup if careful. You could spend money on a lot more pointless things.
The 2.5kW split systems used in an economical manner will use a lot less than their rated output.
Hylife said
10:02 PM Feb 4, 2022
Zero minutes.
Solar panels cannot run anything, you need batteries for that.
Whenarewethere said
10:44 PM Feb 4, 2022
Batteries fill in the gaps when there is less light. If you have enough solar you can run whatever you like.
Peter_n_Margaret said
09:47 AM Feb 5, 2022
Hylife wrote:
Zero minutes. Solar panels cannot run anything, you need batteries for that.
Thatis not correct.
For instance, solar pumps used in the grazing industry for pumping water out of wells and bores have no batteries. The more sun, the more power from the solar panels, the more water they pump.
During the day with an RV set up, the solar feeds the loads direct.
Cheers,
Peter
Hitting the road said
07:28 AM Feb 9, 2022
Depends Hylife...you would note that most solar controller / regulators have an output for direct loads and also to battery. If you are wired to battery all the loads will be wired to the battery. If there is a some load you wish to run direct from the solar panels you'd need to wire that load via the solar regulator terminals accordingly.
Peter_n_Margaret said
09:13 AM Feb 9, 2022
Even loads wired to the battery will be satisfied by the solar first. There is less resistance to do that than to put the power into the battery then take it out again to satisfy the loads.
It just happens.
The only value in wiring loads to the solar controller is so the controller can count them. If you have some other counting system, then it does not matter.
Cheers,
Peter
Aus-Kiwi said
07:53 PM Feb 9, 2022
On pumps on farms the water storage , dam is basically the battery . Cattle can drink it any time ! Unlike A/C when you want it NOW !
oldbloke said
11:13 PM Feb 9, 2022
Noel has not returned
Wayne o said
03:26 PM Feb 10, 2022
I'm surprised no manufacturer of camper trailers and motorhomes hasn't produced an 'off-grid' model.
If they have, I am not familiar with it. Probably leave that to the aftermarket boys, but it would be great if
such a model was available from new. I would buy one because, like a lot of other people, i am looking at
off grid as much as possible.
I know you can go the way of generators etc., but to me, solar power combined with battery capacity would
be ideal.
I am wishing for too much?
Cheers,
Wayne
Whenarewethere said
04:43 PM Feb 10, 2022
Yobarr's 540AH setup with a proper 2.5kW split system air conditioning is the ant's pants. I have a 2.5kW in a bedroom (& 5kW in lounge) in an investment property & they are brilliant.
The 2.5kW split system air conditioners run in economy mode are very economical.
Running at rated output the are over 500% efficient. 490 watts input (180w min - 490w rated - 900w max (3.5kW output 20 minutes boost)).
Running at the lowest setting you get it down to 180w input for 1.0kW output.
So you can get it down to 15amps off 12 volts, let's say 18amps allowing for inverter inefficiencies.
At this setting is would good enough if desperate to knock off humidity & by default template will reduce. Good enough for most nights.
With 1500 watts of solar panels on the roof. Even at 70% efficiency, you are producing 87 amps.
As others have pointed out, your caravan park costs will pay for your free camping air conditioning Rolls Royce set up very quickly.
When running during the day at rated continuous output (& it's generally not continuous unless it is extremely hot & then you most likely have solar input) allowing for inefficiencies you are looking at 50amps. So with 1.5kW of solar you still have 37amps available for charging or other loads.
It's a no brainer, when buying a new caravan, go without the marble bathroom & expensive appliances & put the money into batteries & solar for a split system AC.
Personally, at the end of the day the money is the least of the issues. If you have the payload for batteries, solar panels & AC then it is seriously worth looking at.
Hylife said
06:17 PM Feb 10, 2022
the load connections on solar controller don't work without a battery. That connection is for timing when there is no sun such as a night time security light.
gdayjr said
07:56 AM Feb 11, 2022
Wayne o wrote:
I'm surprised no manufacturer of camper trailers and motorhomes hasn't produced an 'off-grid' model.
If they have, I am not familiar with it. Probably leave that to the aftermarket boys, but it would be great if such a model was available from new. I would buy one because, like a lot of other people, i am looking at off grid as much as possible.
I know you can go the way of generators etc., but to me, solar power combined with battery capacity would be ideal.
I am wishing for too much?
Cheers, Wayne
There is a caravan on the market that is 100% electric powered, big solar and battery set up. Designed to be 100% off grid.
Hi. Probably a question for the techies:
If you are off grid and have 2 x 80 watt solar panels, how long would they run an a/c for?
I guess there are lots of variables but you know what I mean.
(I don't have a van yet and would be pretty frugal if I did use an a/c)
Cheers
Hi Noel,
About a minute for the aircon if you could get it started.........
You need to read up on the solar power section and a big inverter that would drain your batteries real quick.
If you are off grid, a 12v fan is about all you need, but the experts will be along soon to tell your how much solar and battery you need, and I mean that in a nice way.
Cheers Bob
The smallest Mitsubishi Heavy Industries inverter A/C is the choice for off grid use.
You will need at least 1,000W of solar plus about 400Ah of lithium batteries to get a decent run time.
Cheers,
Peter
Hi Noel.Please note that I know little about how an AC uses power,or how much is used,but when I started looking in to a Solar powered AC for my van to handle the high temperature when free camping up around the Kimberley,I was told that it couldn't be done! Anyway,I installed 1650 watts of polycrystalline panels and 540ah of Lithium batteries through a 5kw Victron inverter so I can run my Mitsubishi Heavy Industries 2.5kw AC system 24/7.Keeps my 6 metre van cool and believe me,when it's 45 degrees outside,and even hotter in the van,it is a Godsend! Everything in the van is electric,except my diesel heater,so I have no need to carry any gas bottles.There are several members here who have vast knowledge of how the numbers work,but I am not one of them! All I know is that my solar-expert mate says that the solar capacity should me a minimum of 1.5 times the battery capacity.Others may dispute this,but as I have no knowledge of this stuff,I can't comment.All I can say is that my system works for me! Although I am on the road permanently,and do not use van parks (saving at least $10,000/year) I have never run out of power.Works for me.Good luck with your research, but a word of warning! Solar panels are definitely a product where you should never buy El Cheapo.Won't perform well,and won't last.False economy. Cheers.
Unless I'm in a caravan park on power!
Cheers
As others have said 2 x 80 watts is not enough.
By a long shot.
But.
If you use a 2.5kW split system & not the rubbish the the caravan installers are still using from last century. Use it on an economical setting & use it more for reducing humidity, it will work on reasonably well sized setup if careful. You could spend money on a lot more pointless things.
The 2.5kW split systems used in an economical manner will use a lot less than their rated output.
Solar panels cannot run anything, you need batteries for that.
Batteries fill in the gaps when there is less light. If you have enough solar you can run whatever you like.
Thatis not correct.
For instance, solar pumps used in the grazing industry for pumping water out of wells and bores have no batteries. The more sun, the more power from the solar panels, the more water they pump.
During the day with an RV set up, the solar feeds the loads direct.
Cheers,
Peter
Depends Hylife...you would note that most solar controller / regulators have an output for direct loads and also to battery. If you are wired to battery all the loads will be wired to the battery. If there is a some load you wish to run direct from the solar panels you'd need to wire that load via the solar regulator terminals accordingly.
It just happens.
The only value in wiring loads to the solar controller is so the controller can count them. If you have some other counting system, then it does not matter.
Cheers,
Peter
If they have, I am not familiar with it. Probably leave that to the aftermarket boys, but it would be great if
such a model was available from new. I would buy one because, like a lot of other people, i am looking at
off grid as much as possible.
I know you can go the way of generators etc., but to me, solar power combined with battery capacity would
be ideal.
I am wishing for too much?
Cheers,
Wayne
Yobarr's 540AH setup with a proper 2.5kW split system air conditioning is the ant's pants. I have a 2.5kW in a bedroom (& 5kW in lounge) in an investment property & they are brilliant.
The 2.5kW split system air conditioners run in economy mode are very economical.
Running at rated output the are over 500% efficient. 490 watts input (180w min - 490w rated - 900w max (3.5kW output 20 minutes boost)).
Running at the lowest setting you get it down to 180w input for 1.0kW output.
So you can get it down to 15amps off 12 volts, let's say 18amps allowing for inverter inefficiencies.
At this setting is would good enough if desperate to knock off humidity & by default template will reduce. Good enough for most nights.
With 1500 watts of solar panels on the roof. Even at 70% efficiency, you are producing 87 amps.
As others have pointed out, your caravan park costs will pay for your free camping air conditioning Rolls Royce set up very quickly.
When running during the day at rated continuous output (& it's generally not continuous unless it is extremely hot & then you most likely have solar input) allowing for inefficiencies you are looking at 50amps. So with 1.5kW of solar you still have 37amps available for charging or other loads.
It's a no brainer, when buying a new caravan, go without the marble bathroom & expensive appliances & put the money into batteries & solar for a split system AC.
Personally, at the end of the day the money is the least of the issues. If you have the payload for batteries, solar panels & AC then it is seriously worth looking at.
the load connections on solar controller don't work without a battery. That connection is for timing when there is no sun such as a night time security light.
There is a caravan on the market that is 100% electric powered, big solar and battery set up. Designed to be 100% off grid.
https://www.harvok.com.au/?gclid=Cj0KCQiAjJOQBhCkARIsAEKMtO0FzzQOAjC_Q964t6J_mksG2qhATe1yZ_wN1n57zor7vzXvokA_a78aAu7fEALw_wcB
It has 1000w of solar & 300AH of lithium batteries as a 48v setup.
A piece of cake to setup your own system if one pulls the finger out!
300AH is not enough to run air conditioning, so add more batteries.