Anyone know what the milli amp draw is for a standard glow plug is? I am trying to size the proper battery for a glow system for my four engine bomber.Thanks

In my experience it depends on the temperature of the glow plug. A wet cold coil (e.g. when starting a flooded engine) may draw several amps while a hot coil may draw only 1 amp. The resistance of the glow plug coil apparently increases with increasing temperature.

I'd say plan on an average draw of 2A per glow plug.

Maybe someone else can give you a better answer.

I measured 2.56 amps on a standard glow plug not installed in an engine.

I have the power panel with the remote glow connector. When I start my planes, I normally set the glow plug current to 1 amp. If I go higher than that, I tried it once at 1.5 amps, and it melted the glow plug element.

Brad

On 2 different planes, with 2 different engines (magnum 91, Magnum 120 4 strokes), using an Expert on board glow, and a 2500 ma AA NiMH battery with glow programmed to kick on at 1/4 throttle and lower; each plug used 100 ma a minute at idle.

I remember seeing 800mA being drawn from a C size 2300 NiCD. Results will vary. If you're going to use one driver with four leads... good luck. Remember that long leads don't work well with glow drivers unless the source is quite large or enhanced through electronics.
It seems to me that having a C or Sub-C cell in each pod and a simple switch actuated by the pods throttle servo would work best. I would think a cell having at least 1500mAH capacity would work for each plug (I would go higher.)

100 mAh / minute would be 6000 mAh in an hour. That is 6 A draw.

Most standard glow plugs will only draw 3 amps max. There are a couple Supercharger plugs like the P8 that can draw about 3.5 amps, but a normal #3, #5, #8 and F will not draw any more than 3 amps. Now, it can take a lot less to fire, but that depends on things like the tamperature of the engine, outside temp, fuel mixture, and if the plug is wet or dry. If you're setting up a glow heater to fire a 4 engine plane, you should plan on at least a 10 amp system. To get that kind of juice from 2 volts, you're probably going to need a regulated DC power supply.
If the glow plugs are exposed, you might be better doing each engine separately. I've never tried glow engines in a 4 engine plane. It was rough enough starting / sinchronizing 2 in a P38 and Mosquito.

My most recent experience in this area is with an OS 5 Cyl 4 Str radial engine. I was having problems keeping all five lit. After much experimenting I determined that OS F plugs pulled just under 3 Amp each from a Nicad. I tried a number of combinations of batteries and micro-swithces, but it got very messy.
I eventually settled on a small onboard unit and battery from 42-percent-products. I had some doubt that such a small inexpensive unit and battery would be adequate. The battery pack consisted of 3 c size 4800 mah wired in parallel.
I first wired a bench mock up and was surprised to find that all 5 plugs glowed quite brightly for one hour. So I expect to get a good days flying from one charge
The current pulled by a plug will depend on the applied voltge. Assuming you intend to use Nicad and have very little resistance from wire and other stuff, then allow for 3 amp per plug.
If you want to go the easy route and run all four engines from one unit and battery, contact the 42-percent-products

Thank you guys for the info. I am amazed at how much current draw there is on the glow plug.I was just reading a post about a guy who uses a standard alkaline c size battery in his plane; which is on the entire flight; and he says he can fly all weekend with one disposable battery. How is this possible?

I doubt it stays on all the time. Some folks use a ready made onboard ignighter and some have a limit switch rigged up to do the same thing. In most cases, they'll have it set to turn off at 1/4 or less throttle. I wouldn't suggest something like this on your bomber. Firstly, it would get a little pricy, and secondly, you'd need 20 pounds of batteries ... [X(]

On second thought, you could try one of the ignighters FrugalFlyer used, You would probably need to run a common ground wire to each engine. Don't run a ground from the ignighter to each engine, it will eat your batteries up. The biggest difference between his set up and yours is that all his glow plugs had the same ground.