# Blown air heating and battery power



## stevee4 (Oct 12, 2007)

I am yet to use my MH overnight. A burning ;-) question ?? 

So am I expecting too much for my 2 x 110 leisure batteries to power blown air heating over night without hook up?


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## greenasthegrass (Oct 27, 2007)

We have done 2 nights on one battery in very cold conditions but it continually worried me so don't like to do it. Think you would have no problems it depends on if you use TV, shower etc as well though. Our two nights we had TV on, had a shower each (3 of us) and cooked and had lights on but TV was not on that long maybe an hour or two.

Try it out one night on your drive if that is where you keep the van. Someone will be along shortly to say they got 6 weeks out of theirs am sure! :lol: 

Greenie


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## Chascass (May 10, 2007)

For only 1 night with 2 new fully charged battery's you should have no problems at all, I think they might even last 2 nights but would not like to chance any longer.

Charlie


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## JeanLuc (Jan 13, 2007)

No problem at all. We have done 4 nights at below freezing with 2 x 110 Ah when the batteries were new. A couple of weeks ago, we managed 2 nights at temperatures down to -10ºC but that was with the TV on for a few hours. Didn't have TV fitted when we managed 4 nights!

Philip

p.s. that was with the blown air heating running 24/7 to prevent freezing.


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## peejay (May 10, 2005)

stevee4 said:


> I am yet to use my MH overnight. A burning ;-) question ??
> 
> So am I expecting too much for my 2 x 110 leisure batteries to power blown air heating over night without hook up?


You should have absolutely no problems whatsoever.
We have a similar battery set up and regularly spend 2 - 3 nights off grid with blown air on low overnight in winter.

Pete


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## stevee4 (Oct 12, 2007)

thanks guys I agree I should leave it running whilst its at home to see how it goes...


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## Jean-Luc (Jul 21, 2005)

December 2008 48 hours in La Rochelle 'twas absolutely freezing.
Lights, TV, Sat, Water Pumping not spared plus heating permanently on.
Three and a half year old 2 X 95ah Varta no problem, over 12.1v (50-60% charge) showing before we moved off.


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## greenasthegrass (Oct 27, 2007)

Good stats there Jean-Luc! impressive

Good postage though as we are going "wild" in the Country at New Year oh go on then Wakefield.

Greenie


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## tramp (May 25, 2005)

hi stevee,

you`ll have no probs even with the tv on for a few hours, with the blown air heating its important to remeber theat on initial start up the fan goes into high output mode [plane taking off] depending on how high a setting you have it on and how cold it is  .

After that it slows down so usue less electric [dont ask I aint that sad] so leaving it on 24/7 usese less gas and less electric in the long run also as the batteries are warm they dont have the drop off because there cold.

The forgotten stuff is the recharging after wards 8O as gel or agm take longer to fully recharge than std wet acid batts , aslo I leave the batts to go low then when engine started the alternator goes into fast charge so put a lot back in quick. If in dowt run the engine in the morning for 20 mins to see how much power has gone in.

its fun this camping lark :lol: :lol: :lol: :lol:

merry christmas


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## DJP (May 9, 2005)

There is no definate answer as there are so many variables. 
Outside temp which will also affect the usable power in the battery
Number of Batteries
State of charge when first used for heating.
How warm do you want the inside to be.

Our warm air heating will draw upto 5amps on full power and will run at 2 or 3 amps to maintain 20*C depending on the outside temperature. Assuming it is minus 5 or lower it should run at 3amp constant. Given battery performance at that temperature. One 110amp battery will not last 24 hours 3x24 +72 amps. Two batteries will do. Either set thermostat lower and wrap up a little or retire to bed earlier  
We have 4 x 110 amp batteries and can survive about 4 days before the generator comes out. That is only after running heating 24/7 (20* day and 10* night) and TV about 2 hours per day, plus usual pump usage. LED lights throughout with little usage and battery current draw.
Also consider gas usage. We can empty a 11kg bottle in 4 days.


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## Jezport (Jun 19, 2008)

Heat the van through on hookup before you leave, that way the heating will have less to do once you arrive.


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## barryd (May 9, 2008)

Is blown air heating that important? We hardly every use ours. The Carver Gas fire just gets the whole place warm in 10 minutes from freezing and we have a big van with lots of internal space. I occasionally use the blown on a morning to warm the shower room for Mrs D but on the very odd occasion we would leave any form of heating on at night I would just leave the fire on low but we nearly always switch it off.


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## Grizzly (May 9, 2005)

barryd said:


> Is blown air heating that important? .


You're lucky to have it. We only have the combi boiler and that needs the blown air bit.

I'm following this thread with interest as we shall shortly be overnighting at the ferry port followed by a 50m drive onto the boat and then 24 hours on the boat and then a few km drive ie no great distance to charge. We have a big solar panel but I'm not holding my breath that that will add anything as it might be covered with snow.

I'll be the one prowling the ferry parking at 10pm with the business end of a hook up lead in my hands.... Someone once put on the thread that the Brittany Ferry boats ( Portsmouth- Santander) had hook up on board. Is this so ?

G


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## peejay (May 10, 2005)

barryd said:


> Is blown air heating that important? We hardly every use ours.The Carver Gas fire just gets the whole place warm in 10 minutes from freezing and we have a big van with lots of internal space. I occasionally use the blown on a morning to warm the shower room for Mrs D but on the very odd occasion we would leave any form of heating on at night I would just leave the fire on low but we nearly always switch it off.


Depends on what system you have, we have a Truma 6002 which only works with blown air, there is no separate gas only fire like yours Barry.

Also if you have a double floor, the blown air is also ducted there to keep all the tanks and pipes warm..

Pete


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## GEMMY (Jun 19, 2006)

Truma heaters are the Devils invention,how a thing that costs so much and causes so much grief eludes me

tony


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## greenasthegrass (Oct 27, 2007)

We have Truma 6002E - but its not got the fire just the central heating. Did contemplate using a little gas canister heater but don't know if it would be too fumey in our lounge bit which seems to take some heating.

We are going somewhere heated all evening but the dogs will be in the van unless we can take them with us (doubt it) so will keep it on tick over.

Good thought warming it up beforehand specially as could use leccy only at home to save on the gas.

Once went through 11kg in 2.5 days last year when it as -5 in Preston - was truly staggered! Then found out how the hooky uppy bit worked doh!

Greenie :roll:


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## DJP (May 9, 2005)

> Also if you have a double floor, the blown air is also ducted there to keep all the tanks and pipes warm..


Also acts as a cooling device for the trunking.
I did an experiment recently. The temerature leaving the boiler as it enters the ducts was 164* F (on the outside of the duct). For every metre of ducting the temperature dropped by 15* The temp of the air coming out of the vent at the front of my van was 74* (Boiler is under the bed at the back). A loss over 6mtrs of 90*!
It's amazing how much heat is wasted.


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## Jezport (Jun 19, 2008)

DJP said:


> > Also if you have a double floor, the blown air is also ducted there to keep all the tanks and pipes warm..
> 
> 
> *!
> It's amazing how much heat is wasted.


Im not so sure that it is wasted as it is used to heat the underfloor area and all its pipes etc.


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## barryd (May 9, 2008)

So are you saying that on some vans you can only turn your heating on by using the battery to operate the "compulsory" blown air? Thats bonkers. No wonder people like hookup so much and no wonder we can go 5-6 days on one 110ah battery without it.

Is this to do with more modern vans as our Konitki 640 is a 1996 model. I will want to replace it at some point but I will want an independent gas fire with blown air optional. I dont want anything that relies on batteries as we spend so long off hookup.


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## Chascass (May 10, 2007)

Barry I think that's about right, my last van a 2001 Autotrail Chieftain had blown air and a gas fire (the blown air was heated from the fire) my currant van 2006 Cheyenne only has blown air, and I have always thought it a step backwards.

Charlie


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## barryd (May 9, 2008)

Chascass said:


> Barry I think that's about right, my last van a 2001 Autotrail Chieftain had blown air and a gas fire (the blown air was heated from the fire) my currant van 2006 Cheyenne only has blown air, and I have always thought it a step backwards.
> 
> Charlie


Well it would seem so. I love our fire but I do know a new one would be around the £900 mark if it broke. We had to have a new burner put in at a cost of £75 and the fitter said it was his last one and he didnt know if he could get anymore.

I would just hang onto to our van for ever now as it just works how we want it but it seems parts are not always available.


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## Rosbotham (May 4, 2008)

Can I just butt in on this one? I've got a Truma C3002 (I think?) on my motorhome. It's got blown air heating, and I've only ever used with the blown air on auto, but there's 3 settings for the fans - on, off and auto (cycles on/off according to heat output from elements). Reading what others have said here about the C600x, with mine is it possible to run the element / gas burners with the fans turned off? The Autotrail manual doesn't say anything about it not being allowed.

As I say, hypothetical question as we always have the fans on auto...

Paul


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## Grizzly (May 9, 2005)

Rosbotham said:


> Can I just butt in on this one?
> l


Paul...would you put this on as a new thread ? I'd be interested in the answer to this one too and suspect that people who might be able to answer have not looked at this thread.

Thanks

G


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## DJP (May 9, 2005)

Hi Rosbotham
Your heater could be a S3002?
See here for manual.

Truma Heater


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## Rosbotham (May 4, 2008)

Thanks, you're right, my c0ck up, it is a S3002P. Unfortunately the links on the Truma website are dead so can't get to the manuals there. Luckily it caused me to delve deeper into my own wad of notes, so can RTFM having found the more detailed Truma one versus the Autotrail manual.

I had to delve through 2 manuals, because the S3002 has a separate manual to the one for the Ultraheat electric element. I believe the latter one explains the situation better :

_When using *electrical only* we recommend to set the fan control on position 3 (manual or auto), remembering to set the output level to 2000W (ensure that the fuse protection for the power supply of the camp site is sufficient).

...

The heater operation is regardless of the operating mode (gas oder [sic] electricity) also possible without the Trumavent fan.

To ensure an even and rapid warm air distribution as well as lower surface temperature on the heating unit, we do recommend that you always operate the heater wit a running Trumavent warm air system_

So, in summary, you don't absolutely need to have the fans running (e.g. if you're short on battery power), but they recommend doing so.

Grizzly, with that extra info, are you happy for me not to repost in a separate thread?

Paul


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## Grizzly (May 9, 2005)

Rosbotham said:


> Grizzly, with that extra info, are you happy for me not to repost in a separate thread?
> Paul


Thanks very much Paul, that answers my question very well.

G


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