Battery Powered Preheater

[rissacher]

I anticipate having to park often in an overnight tiedown with no access to electrical in the Northeast where preheat is a must.  I'd love to use my Reiff system rather than buy another (like the propane powered Dragon).  Anyone have experience running an electric preheater using a battery and inverter?  With some quick math, my reiff oil sump heater is 200W and the low-end deep cycle marine batteries are 80 amp hours at 12V.  Watt=Amp x Volts so 200/12 = 16.7Amp and 80 amp hours / 16.7 amps = 4.8 hours (assuming constantly on).  Seems like that would be long enough to give a decent preheat (although overnight would be difficult).

 

Any thoughts?

[larryb]

You will loose 10 to 15% in the inverter. And lead-acid batteries don't like a full discharge. Even deep cycle ones will last a lot longer if they aren't fully discharged. Maybe go to 70% discharge at the most. And cold temps will reduce their capacity. So maybe more like 3 hours of heat for a full charge? If 3 hours gives you enough temp rise, and you combined with a cell-switch so you could call your plane 3 hours before takeoff, it might work. Or use 2 batteries in parallel if you can stand the weight.

 

Larry

[Seth]

http://www.aerothermheaters.com/index.php

 

I saw an earlier version of this once parked outside on a ramp.  I'm not sure if there is a battery powered version, but may be worh looking at.

 

They have a new model that works in 30 minutes, which means it probably doesn't heat evenly, but still better than nothing.  Also, that may assist with the battery issue.  You can always have whoever drops you at your location (should you do that) use an inverter on their vehicle, or pop the hood and bring your own inverter, to power a device.

 

-Seth

[BorealOne]

I'd be thinking about a small gas powered generator...

[yvesg]

Rissacher, My tie-down has no power and I need to preheat each time. We built a propane pre-heater a few years back that needed 120V to power the fan. This could be powered using an inverter. In my case since I am a tinkerer, I simply replaced the 120V AC fan by a similar 12V fan to avoid having to use an inverter. A 4 inches metal duct (flexible) is providing the heat. We open the cowl flaps, insert the duct in there and cover the cowling with a sleeping bag while we pre-heat to prevent loosing heat out. When the cylinders are warm, you can start the engine. This would not take more than 30 minutes. The heater provides 35 000 BTUs. Let me know if you want to see pictures. Yves C-FQKM