(POSSIBLE?) Preheating off the grid - Mobile Power Bank

[phillipny]

Hey guys,

For transient tie-down aircraft, preheating in the winter is always an issue. Without an electrical post nearby Im not able to use my electric heating equipment on the plane.

Last winter I switched my home base to Republic airport KFRG in Long Island, NY and there are about 150x planes out there without electricity. Most are not preheating and just cold starting, and letting it idle for 15-20mins until the oil temp comes up.

I put together a setup using my car, an inverter and a propane tank and one of those big Dyna-Glo heaters from Home Depot
http://www.homedepot.com/p/Dyna-Glo...Air-LP-Gas-Portable-Heater-LPFA125H/203633490
Another model was the red dragon setup
https://flameengineering.com/collections/engine-preheaters

But Ive been trying to come up with a portable solution I could leave at the field in a lockbox: A really good deep-cycle battery (or 2x), a properly sized inverter, maybe a solar panel on top and then just looking for 3-4hr of preheat on a 300W (@ 120V) engine heater.

I checked with any other airports in my NYC area and all of them (Linden, Caldell, Morristown, Republic, Whiteplains, etc) have no or limited electricity on the field. At least 500x planes in the same position as me that have a Tanis built into their plane but can't use it.

My current setup is
- 2x Trojan T105 batteries in series (for 12V)
- 1x cheap analog power inverter, modified sine wave
- Switchbox for remote start
- and cabling

Currently swapping the dead batteries with freshly charged at home 2nd set, and its little heavy for the swapping but has been working so far. Got 7.5 hours of remote start/preheat this way and all water tight so it can live outside. Our VIP below enjoyed the warm cowling blanket before the flight :0

Have any of you done this and works reliably?

And any experience with solar in the winter, how long it takes to recharge a big deep cycle battery? I think the RV guys would have more experience to share.

Phillip

 

[Acrodustertoo]

Angela merkel will be looking for work soon, she is good at blowing hot air.

 

[Stewartb]

My airplanes park outside in Alaska. I don't have electricity at my tie down. 100% of my electric preheat is done using a generator. Mostly an older 1000watt Yamaha EF1000. I use a bicycle cable and padlock to lock gennie to gear and leave it to run my Reiff Turbo XP system a couple of hours before I go. That's what most of my tie down neighbors do as well. Reiff provides good, safe, and well distributed preheat in the shortest time of any system I know of.

If you like gadgets and don't need much heat look at this link. http://maxpreheat.com/index.html

 

[AKBill]

I also use a generator to power my E-Z heat oil pan heater. I have and external plug for my battery and will hook up a battery charger at times. My generator is 1500W. At times I will also hook up a Red Dragon to heat cylinders and put a small heater in the cabin.

I normally preheat for 3 to 4 hours. I feel safe leaving the generator run while I'm not there, and only run the Red Dragon when I can watch it.

 

[murphey]

Sunshine, warm blanket, what's not to like? I know mine prefers to stay home. Phillip's (switchbox), on the other hand, loves flying.

 

[3393RP]

Your heater uses just .89 amps when operating. It'll run for over 100 hours on your 6 volt Trojans.

Just wanted to let you know so you don't have to lug 'em home for a recharge very often.

A portable solar panel probably won't put out enough amperage to properly charge the Trojans. If the current is insufficient it will result in plate sulfation and an early death.

Insufficient current can also eventually result in the batteries having diverging open circuit voltages due to the slight difference in impedance they will have. Without an occasional equalizing charge (about 14.7 volts) this will also result in a reduced lifespan.

Do a Google search for "recharge C rate" and "battery equalizing charge" to determine the required recharge current that will keep the batteries healthy.

Your gadget is a pretty slick setup.

 

[Stewartb]

My calculator says you'll use 27.6a @12v to power that heater through an inverter. That'll be hard to sustain without a fairly big PV panel, and that'll dictate a charge controller.

 

[murphey]

Related topic - you may want to get insulated prop covers....those are two very large heat sinks attached to the engine.

 

[arkvet]

I'd go the generator route. Super easy and if you're like me you'll always find the generator comes in handy at other times when the plane isn't using it. I've got a 2400 watt Yamaha inverter generator I use around my farm all the time. Would work great to power my Reif system but would be overkill. I don't use it for this purpose as I'm in a personal insulated hangar. Just keep mine plugged in.

 

[murphey]

I'd go the generator route. Super easy and if you're like me you'll always find the generator comes in handy at other times when the plane isn't using it. I've got a 2400 watt Yamaha inverter generator I use around my farm all the time. Would work great to power my Reif system but would be overkill. I don't use it for this purpose as I'm in a personal insulated hangar. Just keep mine plugged in.

Can some generators be started remotely?

 

[StinkBug]

If it has electric start you could wire up a remote controller, but generally that'll put you into a generator that's quite a bit bigger than you really need for this job. The little Honda EU1000/2000 units are fantastic for this kinda thing, and are light enough to pick up and carry, or even throw into the plane and take with you. They are also damn near bulletproof.

 

[phillipny]

Alright, another month of testing and with the help of some great pilots... V2 working even better.

This system is definitely working for me at my NYC airport with no tie-down electricity. I get about 8 hours of heating and a bigger system would get less, about 4 hours. Swapping the batteries (for charged ones) is a pain at the moment... but ill figure that out better at a later time. For now, shlepping is working, and using a dolly it's not bad.

For the electronics, we had to custom modify the inverter and the cell switch. Switchbox working off 12V direct now... no 120V operation through the inverter just to keep it alive on the network. In real life, this killed the batteries after 3 weeks of sitting while I was traveling in Europe last month.

Then, a power inverter was spec'd that had a physical remote switch ability. We modified that physical "button" so it can be "pressed" by the Switchbox remotely. One button in the app to turn on the inverter and another to pass 120V power to the engine heater.

This new setup involves 0 parasitic draw from the inverter and lets you have nearly full capacity of the batteries at all times.

Ill report back in a few weeks with real life data and how its working. But so far, really enjoying the system vs the red dragon I did last year. Plane is in annual this month, and will probably get a bigger sump and cylinder band heaters put on. More wattage = less battery capacity but also less preheating time needed.

Pics below

 

[phillipny]

Some new results. Its working great.

With the new setup I installed last Sunday .. the system has been technically OFF all week and ready to be used and remote started for the inverter and then heater. Yesterday at 2pm I remote started the inverter and arrived to the airport at 10pm, batteries still going and engine temp warm and started right up!

The ambient temp is 32F, and the batteries say they are at 11.1V or 10% charge remaining.

The next step will be some kind of cut-off voltage switch where it will disconnect batteries if Voltage goes below X amount. I think 20-30% charge will keep them safe if left "dead' like this for a few days.

Before I flew off, I swapped the dead batteries with the fresh ones in the car and the setup is working so far.

An idea for the future would be an app which provides a sort of W/B envelope visual.. and takes into account
- wattage of your heater
- ambient temp
- maybe even wind speed
- size of battery bank
- covers on/off (cowling and/or prop)

And will calculate a rough estimate of how long you should preheat for. After gathering a lot of data, a rough visual could help to make sure you're in the envelope

Just landed at my other home airport, in Rhode Island, and also about 50x planes with no electric in the tie downs. Gotta get some prototypes made so you guys can try it for free.

If you're local and want a free prototype to try... PM me! Ill fly it over, not that heavy
P

 

[gkainz]

Repeated discharges down to 11.1vdc is going to destroy that battery pretty quickly. Do some googling on RV deep cycle battery charge discharge info. I think you'll find that discharging deeper than 50% significantly shortens the life of a deep cycle battery, and recharging anywhere close to 100% takes some extra work and/or a smart charger. RV.net/forums Tech Info has a bunch of good info from knowledgeable folks who have invested a lot of time and testing into 12vdc and solar systems.

 

[pmel22]

Hi I'm based out at Brookhaven and use the red dragon, that said, your setup is pretty neat...

 

[phillipny]

OAT now around 15F here in New England.

Lots of PMs asking me to try Prop Covers/Insulated... and see how it effects the oil temp from preheating. A DIY solution was Walmart gun socks, and It fits perfect, but not insulated. But they sell a $2.50 fleece roll in the home goods department.

So both went on last night for preheating and flying out this morning. Ill report back with info and seems the prop covers are OK for $5 each side. If anyone has a DIY solution for the spinner, let me know.

 

[phillipny]

That made a huge difference, I was shocked yesterday when I came over to the plane.

My first time using "insulated prop covers" (ie $10 gun sock + fleece combo) in the winter and the difference was very big.

Checking my oil dipstick revealed lots of steam coming off into the air and drips like it was summer time oil. Hmm, removed the prop covers and the blades themselves were warm! Incredible.

The plane started right up, like before, but the oil temp was reading in the 80s. About 30% warmer oil just from the prop covers. For years I would only see 60-70F when parked outside and 10 OAT and windy.

Big big difference, you guys should try using the custom prop covers or DIY. Highly recommended and wish I was doing this last few years.