Bongo Fury

Does anyone know where in the archives I can find the wiring for allowing a 24 volt Eberspacher/Webasto heater to work off two 12v batteries.

Could've been done by wryster?????

Do you just wire in series? That would give 24v.

dandywarhol wrote:Does anyone know where in the archives I can find the wiring for allowing a 24 volt Eberspacher/Webasto heater to work off two 12v batteries.

Could've been done by wryster?????

I thought it was "Yamaha"?....

Also the write up was on bongoogle....but that seems to be down now..... I thought I had saved it as a document but as yet have not dug deep enough to see...

Do you just wire in series? That would give 24v.

IIRC it was a bit more complicated than that, as the 2 batteries were a starter & leisure set up, with split charging etc, and a cunning we einterfacce box which derived 24v form them for the eber, but allowed them to carry on as independent batteries in all other ways.

Thats right Dave - it was a cunning box of tricks devised by wryster and used by yamaha. it allowed the main and leisure batteries to connect in series to only operate the eber.
I noticed bongoogle down too - is it only temporary?

Its suspended looks like the address is up for grabs or will be shortly, it expired in January 2011.

I'm pretty sure it involved using some hefty diodes to stop the batteries feeding each other but I can't remember exactly how it was done.
I was considering doing it as the 24v ones are a lot cheaper than the 12v but eventually got a 12v at a decent price.

I have found some info on my ImageShack account - forgotten I'd uploaded them - hope they help a bit.

http://img220.imageshack.us/i/1224switchll5.jpg/

http://img483.imageshack.us/i/p2080066hp9.jpg/

http://img63.imageshack.us/i/p2080067xd2.jpg/

The relay was a 4PDT 12v jobbie from Maplin - not ideal as only rated at about 12A handling - but unable to source anything heavier at the time - a specialist contactor would be ideal, if a suitable one was obtainable. There are also a bank of 4 fuses in the box - and in use, I have only ever had to replace one on one occassion.
I also used a transistor to switch the relay coil to avoid the charging lamp on the Bongo glowing, but can't find the circuit for it now.

Looking back - I am still glad I went the 24v route - my Webasto AT2000 cost me £330 brand new on eBay - and I really enjoyed the fitting of it (at the time I was more nimble)!!

The only thing I never got around to doing was to replace the internal thermostat with a cabin-mounted one - an easy enough job. This caught me out once when we pulled over one night for a snooze, and the heater wouldn't fire up - I eventually realised that it thought the engine compartment was warm enough - and didn't need any more heat!! One it had cooled down a bit, all was well again.

Bear in mind, though - this installation can ONLY be used when you're parked up, and the engine is stopped, so the relay is off, and the 24v is available for the Webasto.

Mike

Thanks for that Mike.