/ Campervan Electrics
I have an Erberspacher heater for my van, but it requires 24v power to it. It needs 40W for running, but 500W (+/- 10%) at start up.
I'm trying to work out how best to do that, and have come up with the following ideas, could someone suggest if they'd be likely to work?
1 - buy a 12v to 24v transformer, rated at 500w. Run power from my 110Ah 12V batteries to the transformer, plug in the heater...job done.
2 - Buy 2x 12v to 24v transformers rated at 250W (cheaper than above) - some how wire them up to give 500w power? is that possible?
With either of the above two options, would the transformers always create 500W, thus draining my battery pretty quickly, or would they drop to the 40W as soon as the demand from the heater drops?
Option 3 - Wire two batteries in Series to give 24v power, linked to heater...job done - but would the batteries produce sufficient power for the start up? If not, with some funky wiring, could I set it up so that the Engine is on for start up, and then the continual running can be done off the batteries?
Sorry if I'm being really thick, or missing anything really obvious, I'm not a spark, and have very limited knowledge of electrical theory!
x1 electric hook up lead
so - new question - assume I'm nowhere near an electric hook up...
How would you charge a 24V battery bank?
Would it not be simpler just to put the eberspcacher on ebay, and buy a 12V version?
> so - new question - assume I'm nowhere near an electric hook up...
? So where are you getting the AC from?
Transformers are AC devices. The won't work well on DC batteries. Any electronics conversion will probably cost much more than buying an appropriate heater; not to mention all the conversion losses.
Why did you buy a 24v version?!
It is possible if you have 2 batteries (van and leisure). With a few relays you can supply the 24v required for the heater and charge from the alternator using a split charge relay. Try bongofury.co.uk some one posted the wiring diagram on there.
<Still being devils advocate> Why would you be anywhere other than a nice comfortable Caravan Club recommended caravan site? :-)
I am afraid I can't help on the electics other than suggest that the more expensive option seems simpler and less likely to spontaneously burst into flames.
It isn't a great idea to connect forced air heaters like the eberspacher ones in such a way that the power could be inadvertently cut (e.g. by an isolating switch or turning the engine on) before the unit has powered down.
> Option 3 - Wire two batteries in Series to give 24v power, linked to heater...job done - but would the batteries produce sufficient power for the start up? If not, with some funky wiring, could I set it up so that the Engine is on for start up, and then the continual running can be done off the batteries?
connect in series when the heater is in use,
and connect in parallel when you need to charge the batteries.
I suppose you could have it set-up in series the whole time and just take it in turns which battery you charge at a time
>get a 12v Eberspacher.
that's the best answer
Aye, or just get a propex.
Elsewhere on the site
Every so often you meet someone in climbing that makes you take a step back. Someone with a fire in their eye, passion in... Read more