WEBASCO HEATERS

[eidiohir]

DOES ANYONE HAVE ANY INFO. ON HOW TO RIG UP A S/H HEATER OBTAINED FROM A TRUCK.THE PROBLEM IS NOT WITH THE INSTALLATION AS SUCH BUT WITH THE DIFFERANCE IN VOLTAGE ie THE HEATER RUNS ON 24 VOLTS WHEREAS THE BOAT OPERATES ON 12 VOLTS.I KNOW THAT IT IS POSSIBLE TO CHANGE 12VOLTS TO 240VOLTS USING A INVERTER BUT I DON'T SEEM TO BE ABLE TO FIND SOMETHING TO CHANGE 12 TO 24.IT MAY BE POSSIBLE TO INSTALL A SECOND BATTERY AND A CHARGING SYSTEM TO GIVE ME 24 BUT I WOULD NOT BE ABLE TO DESIGN THIS MYSELF

 

[VMALLOWS]

You can certainly convert 12v DC to 24v DC using an inverter/rectifier, and I'm sure they're commercially available.....but its not going to be cheap. One problem is that the heater is going to need a huge (aprox 10-15amp at 24v) current for the glow plug when it starts up. The ongoing current will be about 2amp. Your easiest sollution will be an extra 12v battery in series with your main boat battery, but yes, it will need some thinking as to how to charge it. It's not technically difficult to achieve, but likely to be either a bit cumbersome to do manually, or, --again--, expensive.

Out of interest, how much did a 24v Webasco ex-truck heater cost you??
My Eberspacher is on its last legs and I might go that way.

 

[Guest]

I would be interested if somebody has solved this one. When I looked at it there are some serious problems with the switching between 12 and 24 voults for charging. For instance the reconection to series 24 volts could lead to heavy current flow between the good battery and the bad battery if they were not in the same condition. This momentary heavy current could cause damage or at worst a fire. The other big issue is the grounding of the negatives for charging - both have to be grounded if they are to be charged at 12 volts in series- however, for operation the negative of one battery gas to be connected to the positive of the other to form a series circuit at 24 volts. The problem is the safety of the make and break switching. The thought of positive going straight to ground in the event of a fault is frightening.

Food for thought perhaps - but somebody out there must have a solution!!

PZ

 

[Robin2]

People who fly electric powered model airplanes have chargers that can charge large nubers of NiCd cells - presumably 24v or more. I haven't got a magazine (Quiet & Electric Flight International) beside me so I am not sure if these only work of the mains or can work off a 12v supply. Also, I'm not sure if they can be run continuously.

It would be worth while checking out the model flying magazines.

If you can find a solution to charging the 24v battery that would probably be the simplest solution as the battery could provide the starting current for the heater and the running current could possibly be met by the charger.

 

[AlanPound]

There is a real neat probable solution for this one.... Check out http://www.yandina.com/24VoltBattery.htm the application described is deriving 24V to drive a (high current) bow thruster, but the situation is pretty much the same.

Regards

 

[Phill]

Changing 12VDC to 24VDC does not involve inverters and anything so complex. It only needs a transformer. I saw lots of them in Dick Smith Electronics shop (Australia), all for various combinations, 12 volts to 3, or 4.5 or 6 or 24 or whatever voltage needed. Reading the others' comments, check the amps needed to run this heater (I'm not familiar with it). Then go to an electronics shop, have a look at their transformers and confirm it all with the salesperson: that it's the correct capacity. A transformer is easy - 2 wires in & out for the 12volts, and another 2 wires for the 24 volts, red and black. Get the salesperson to teach you something about the wiring - it's their job to make sure you buy what is appropriate and know how to put it together. Cost, approx $20 to $30 max.