Hymer and WATT Fuel Cell

I'm a tad confused... would this replace the underhood generator to charge the battery? ...using propane? RTs would need bigger propane tanks then.
 
500W of continuous power at 0.34 lb/hr? The conversion rate isn't bad, but that's hardly going to power an AC unit. You'll need three of those units and then we are talking 1lb/hr. So as someone else mentioned, they are going to need a bigger tank ;)
 
You need to put it into the context of the Fuel cell running 24/7. At a 0.5kW capacity it should provide 12 kWH/day. Normally an A/C unit would not run continuously but the FC would continue to charge the battery. To really get an handle on things you would have to put a kWH meter on the A/C unit to see how much energy it actually uses over a 24 hour period. You would still need a battery as a storage device to even out the load over a 24 hour period.
 
Looks like about 2 hours of running and .75# of propane to get 70ah, which would be about 1 days worth for many with compressor frigs of the 5ish cf size or smaller. I think a 30# tank like most of us have has about 24 usable, do you would be good for month of power if you didn't need the propane for anything else. Not all that bad, I guess, but I would be in line to get one if it ran on gasoline.
 
My question is, how much is this going to cost? Truma tried propane fuel cells with their VeGA line, and quietly killed them after a few years.

If they are reasonable (less than the price of the EFOY cells), this would be a technology that kills propane fridges dead.
 
Looks like Efoy has US dealers in SC and on the west coast. This looks like the answer to the 24/7 small generator suggestion in the other thread. With a decent lithium battery bank to handle surges, this would be pricey but awesome.
 
Hmm, the Efoy comfort series has a max altitude of 2000m, not so useful everywhere I go...I wonder if they all have a relatively low limit?
 
Hmm, the Efoy comfort series has a max altitude of 2000m, not so useful everywhere I go...I wonder if they all have a relatively low limit?

I think the Efoy uses methanol, so that might have something to do with it because of the low pressure at altitude and the vapor pressure of methanol. Of course it could also be an air fuel ratio thing that all would have.
 
EFOY fuel is too expensive and unobtanium. I don't believe the propane fuel cell is real but when/if it is it solves the fuel problem.
 
Constantly stopping to find more propane is not my idea of good time. Diesel and gas do a much better job of generating power to run AC and other appliances.
 
A 500 watt fuel cell is not intended to run A/C or a microwave. It is intended to keep the batteries charged with the increased power draw of compressor fridges and entertainment centers.
 
500W of continuous power at 0.34 lb/hr?

The conversion rate isn't bad, but that's hardly going to power an AC unit. You'll need three of those units and then we are talking 1lb/hr. So as someone else mentioned, they are going to need a bigger tank ;)


What is the thermal conversion efficiency?

Someone got a calculator? :facepalm:
 
Someone please check my math, I'm only getting 23%

.34 #/hr is 155g/hr
155 g * 2200 KJ/mol / 44 g/mol = 7735 KJ potential
500 watts.hr * 3.6 KJ/w.hr = 1800 KJ converted
 
Fwiw, I found a site claiming a 3.6 kw Onan consumes 0.7 gal/hr of propane, by similar math that works out to 18% which is in the ballpark of what I expected. I'll see if I can find a claim of methanol usage of the Efoy. My math still need double checking..
 
Hmm, similar math for the methanol in an Efoy gives 22.5%
8.4 kg at 21 Mj/kg vs 920 ah at 12v at 3.6 kj/wh

[Edit] elsewhere the Efoy claims 0.9 l per kwh, which is about 25%, so that's the range, a bit better than the Onan, but temperature sensitive including for storage. There is no fee lunch I guess.
 
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IIRC... that's a better ratio than converting electricity to light,
or converting gasoline to horsepower.
 

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