aircon on the move (1 Viewer)

[Stuartandshaz]

Hi there,
I am trying to get my motor home air-conditioning working with my inverter. At the moment i have
2x leisure batteries, 1x 110amp and 1 x 85amp these are wired up to a ring 2100 inverter and is charging via a split charger from my alternator. I am not getting sufficient charge to keep the batteries topped whilst driving the split charge wires are getting warm and obviously the aircon unit is drawing more than i am putting in, according to the inverter i am drawing 270w (inc fridge). I am planning on a trip to Greece soon and will require the aircon to work whilst driving, could you advise
Me what i would need to to get this working correctly i.e solar panels, extra batterys.

Kind regards
Stuart

 

[DesRes]

What's the size of your A/C system powerwise? I think you could be asking a bit much of your battery/inverter setup. Solar panels are unlikely to give sufficient top up charge and your van alternator will only charge up to it's rated capacity whilst on the move.
You can't get more out than you're putting in...
I'd be interested to read if anyone else has achieved this.
My last van we had cab A/C for on the move and a 240V roof system for on site. The most I ever used the inverter for was the toaster, and that was with a three leisure battery setup!

 

[Snowbird]

Am sorry to tell you that wont work. Your aircon will pull more than your alternator will put in. Add to that the fridge and all the other bits and pieces that run from your batteries and it becomes a definite no no.

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[DesRes]

Am sorry to tell you that wont work. Your aircon will pull more than your alternator will put in. Add to that the fridge and all the other bits and pieces that run from your batteries and it becomes a definite no no.

That's what I thought....:thumb:

 

[Stuartandshaz]

air con

Its a dometic b1500 and no its not working, just bought a 100watt solar panel and controller not sure if it will help the alternator out in hot weather, still need to fit it, and will probably put a 3rd leasure battery on with it. Wish i had bought a van with cab aircon

 

[hilldweller]

just bought a 100watt solar panel and controller not sure if it will help the alternator out in hot weather

A bit. Your alternator is more like 800W maybe more.

But that 100W is with the panel pointing direct at unobstructed sun, just being flat loses you 30%.

The aircon is rated 800W.

So you aren't that far off but you will be running everything in "She'll no take it Capn."

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[pappajohn]

A bit. Your alternator is more like 800W maybe more.

But that 100W is with the panel pointing direct at unobstructed sun, just being flat loses you 30%.

The aircon is rated 800W.

So you aren't that far off but you will be running everything in "She'll no take it Capn."

only in heating mode Brian....cooling mode is 650watts.

Technical Data
Type Roof
Cooling capacity (kW) 1.5
Full Load, cooling (A) 2.9
Capacity (BTU/h) 5200
Power (V/Hz) 230 / 50
Refrigerant R407c
Dimensions (L x W x H) (mm) 980 x 650 x 235
Dimensions (roof opening) (mm) 400 x 400
Net weight (kg) 30
Circuit (A /sec) 14/0.15
Consumption, cooling mode (W) 650
Consumption, heating mode (W) 800
Fan speed (kW) 2.0
Fuse (A) 4
Roof thickness (mm) 25-45

a minimum of 54ah from the battery/alternator plus losses....so the alternator should be man enough, just.....but the engine wont be charging the leisure batteries at that rate.

you would need to run the inverter/aircon from the engine battery ONLY with the engine running.

 

[Wildman]

you say cables are getting hot!!!!!!!!! Fit larger dia cables before you have a fire and make sure everything is fused to suit. That will gain you a little more power rather than lose it to heat.:thumb:

 

[Reallyretired]

You may be able to replace the alternator with a higher output one, as used on ice cream vans.

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[MikeD]

air con on the move

Hi there,
I am trying to get my motor home air-conditioning working with my inverter. At the moment i have
2x leisure batteries, 1x 110amp and 1 x 85amp these are wired up to a ring 2100 inverter and is charging via a split charger from my alternator. I am not getting sufficient charge to keep the batteries topped whilst driving the split charge wires are getting warm and obviously the aircon unit is drawing more than i am putting in, according to the inverter i am drawing 270w (inc fridge). I am planning on a trip to Greece soon and will require the aircon to work whilst driving, could you advise
Me what i would need to to get this working correctly i.e solar panels, extra batterys.

Kind regards
Stuart

I have a freshlight on my van. It draws approx 5 amps when cooling on 240v.
That is approx 60 amps on 12v - I am advised you need a uprated alternator to power this and big, big cables.
I suspect not much change from a big "k" for the invertor kit and fitting. Alternator extra!!!!
Ouch!

 

[Reallyretired]

Might be cheaper to fit cab aircon

http://www.readerair.co.uk/

Cost around £1500

 

[Minxy]

you say cables are getting hot!!!!!!!!! Fit larger dia cables before you have a fire and make sure everything is fused to suit. That will gain you a little more power rather than lose it to heat.:thumb:

That's the most IMPORTANT part that I picked-up on from the posting too!!!

Just stop doing it the way you are currently - if you set fire to your camper you might not get it replaced by your insurance company as you are doing something 'unadvisable' with it ... and doing so knowlingly!!!!!

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[wivvy's dad]

Simple answer........




Go North for your holidays, then you won't need air-con




Try Abisko in Sweden

 

[SuperMike]

In an American RV, start on board generator whilst travelling, it will burn about a gallon every two hours and then run both house air con units. :Tongue1:

Super Cool. :Cool: :Cool:

 

[hilldweller]

I have a freshlight on my van. It draws approx 5 amps when cooling on 240v.
That is approx 60 amps on 12v - I am advised you need a uprated alternator to power this and big, big cables.
I suspect not much change from a big "k" for the invertor kit and fitting. Alternator extra!!!!
Ouch!

Nearer 100A I'd say. The average leisure battery could take that for about a quarter of an hour.

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[Stuartandshaz]

air con

well just spent approx £800 in total on items that will help a little but not do the job, Solar panel came this morning so will get that fitted first then i will try running the inverter from the starting battery and give that a test. the split charge wires are only getting hot when using the invertor with the aircon unit, its wired correctly and using the recomended size of wire so this should not be an issue if its not running the inverter or the aircon. Actually going to live in the van as we have sold our house and this is the only home we got.
Having lived in Bulgaria for the last 8 years i know how hot it is in the area's of europe we are going to be traveling through so the air con is very important (98 degrees in Bulgaria the other day) so we are going to melt driving in that.

 

[MikeD]

Nearer 100A I'd say. The average leisure battery could take that for about a quarter of an hour.

You are correct Brian - 100amps

I need to go back to school or grow some more fingers oh:

 

[bungle.bear]

only in heating mode Brian....cooling mode is 650watts.

Technical Data
Type Roof
Cooling capacity (kW) 1.5
Full Load, cooling (A) 2.9
Capacity (BTU/h) 5200
Power (V/Hz) 230 / 50
Refrigerant R407c
Dimensions (L x W x H) (mm) 980 x 650 x 235
Dimensions (roof opening) (mm) 400 x 400
Net weight (kg) 30
Circuit (A /sec) 14/0.15
Consumption, cooling mode (W) 650
Consumption, heating mode (W) 800
Fan speed (kW) 2.0
Fuse (A) 4
Roof thickness (mm) 25-45

Using the AC figures,

Voltage x current = power, 230v x 2.9A = 667watts. if we now convert this to DC not taking into account losses.
667watts divide 12V = 56A

I suspect by the time you take losses into account plus fridge and battery charging you will be closer to 70Amps. I personally do not think your vans standard alternator will keep up with this kind of current.

You could fit a larger alternator with a sterling B2B charge regulator and replace all of the cabling to suit the higher current flow, as well as a higher current spilt charge relay, but I suspect this could be close to the cost of having a on board generator, plus with a on board generator you can use the AC when not driving along without a hook up.

Anthony

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