s/h eberspacher

[eidiohir]

I have been given a second hand heater that was obtained from a lorry cab.. The catch is that they run on 24 volts not 12v.
Can they be changed to run on 12v instead?
Or maybe there is a way to turn 12v to 24v cheaply?
My son has a 27footer which would benefit from some heat so fingers crossed

 

[Searush]

Not an easy conversion. Affects pump, fan, controller & glowplugs I think. But if you got it for nowt, it may be practical.

Otherwise, sell it on e-bay (about £100) & buy a 12v for £250

 

[Anthony]

Not easy to change, the controllers are built according to the operating voltage etc. They also draw a large current upon starting so whilst it is possible to convert a 12v supply to 24v, doing so and providing enought current is going to be an expenive operation that negates the benifit of getting the unit free.

 

[FlorealIII]

You will have to replace motor , glowplug , relays and fuel pump . There is no easy and cheap way to transform 12 V DC to 24 V DC , certainly not for the power ( wattage ) you need . You are facing an impossible task in my opinion !

 

[VicMallows]

There is an easy (though not elegant) way.............

Use an additional 12v battery in series with your main domestic battery to give 24v.

Of course you now have the question of how to charge the extra battery. Depending on your heater usage and boat usage this could be:

. take battery home for charging
. manually wire in parallel with domestic to charge when motoring and heater not required.
. rig up an automatic changeover to achieve the above (somewhat complicated).

Vic

 

[eidiohir]

If there is a cheap reliable method of changing 12v to 24v even at a low current could it be used to charge a 24v battery bank from the ships battery which in turn would run the heater?

 

[simonfraser]

cheaper & simpler to sell the 24v one and buy a 12v one instead

 

[bigwow]

When I was special saloon car racing in the 70’s, to start the BDA engine the auto electrician rigged up a system of sending 24V to the 12V starter using a couple of solenoids and 2 batteries but leaving all the other electrics 12V .

 

[eidiohir]

OK get the message.
Its part of my make-up to want to find a way around difficulties and sometimes this can lead me to spend time and money solving a problem which doesn't need to be solved just to satisfy my own curiosity.Maybe this is one of them.

 

[lw395]

Couple of small 12V lead acids, eg motorbike or alarm types, in series, charged by a 12V to 26V dc-dc convertor could be a possibility. The batteries wouldn't have to be the best in the world so ones discarded from electric start bikes might do.
The dc-dc is more of a problem to get cheaply, try ebay or perhaps maplins for something intended for laptops, but a lot only go up to 19V or so. Some may have poor regulation and gas the batteries, so take care, particularly with 'sealed' batteries.
Also check that 0V or ground is only connected where you expect, some dc-dc's are floating, some even invert!
If you can find an isolated 12 to 14 converter you could just put one battery in series with the ships battery as suggested above, and charge it from the ships 12V.
The problem with all this can be the input 12V varying from 11 to 14.5 and the output needing to be fairly well regulated.
Also remember Eber's are touchy things and will 'lock up' if you try to run them on dodgy volts too often, or switch them off by removing the supply rather than the control wire (which lets them do a shutdown sequence.
Hope that helps!

 

[swampthing]

Check this------------- 12vdc ---inverter---240vac----transformerand diode---hey presto 24vdc