funnotcrazy

Will be starting a Saito 1.80 soon. It has about 4 hrs on it, packed away for 10 yrs now. Oiled & turned over w/out plug on occasion.

Anyway, for the first few starts I would like to use my Hobbico Torquemaster starter, but I do not want to let the "blue smoke out" (my term for burning up electronics - you know - let that blue smoke out of it and it doesn't work anymore!)

After it has been started a few times I will use the "backflip" method I used with my smaller 4 strokes. Do not want to burn up my starter. I will try 2 12 volt batts in parallel.
Will 2 batts in series (24 v) burn up starter? Cannot afford $150-200 starter for the larger engines.

Any other suggestions welcome.

JohnB96041

I use the torque master 180 on my Saito 1.80 all the time. Have used it on my Saito 3.00 twin but is slow turning it over.

flyinwalenda

My Feedback: (5)

If it's the Hobbico 90 starter it won't turn it. If it's the 180 model it should be OK as long as the 12volt packs are healthy .
Yes use (2) batteries in parallel to gain some extra current punch.
Do not run these starters on (2) batteries wired in series/24v.
Check the classifieds for a Sullivan Dynatron starter. They can handle 24v and can be bought used for around $65.00,

wcmorrison

My Feedback: (2)

Two 12 V batteries in parallel results in 12V not 24V. Two 12V batteries in series results in 24V. My 12 Volt Sullivan starter can draw up to 75 amperes on starting. So I am thinking your two 12 V batteries in parallel ought to work just fine. You did not say what the capacities of the 12 volt batteries are. I am suspecting you are using two 12V 7 Ampere Hour rated batteries. I am sure they will do the job for you. I would think those gel pack batteries can deliver probably a peak of 30 or more amperes under a short duration load. Even a simple 1.5D cell flashlight battery can deliver up to 25 amperes for a very short duration. So you have plenty of power available to you. So I would try the two batteries in parallel. Using them in series may do damage to your starter.

Remember in this case it is not the voltage available, it is the current that provides the power. I start my .91 four strokes with a 3S2200 LiPo battery. That is 11.1 volt battery rated at 2.2 Ampere Hours. But in a very short duration like a engine start it can deliver a lot more that 2.2 Amperes and spins the hell out of the .91.

I have little faith in Hobbico starter. I had one and junked in favor of a Sullivan. My Hobbico could not turn over a .91 four stroke engine using a car battery as a power source. The car battery, while old, probably could deliver 200 or so ampere hours of power. Not enough to start a car but much more that a model airplane engine would ever need to start it. When I used my Sullivan with the car battery I am pretty sure it could start a 1.80 with out batting an eye. It could handle the power, as the man said it is the way it is wound.

Good luck.

speedracerntrixie

My Feedback: (29)

I start up my YS115 fueled with up to 50% nitro with a 12V HD starter hooked up to 4s 5000mah lipo battery. Never an issue.

Sport_Pilot

A 12 volt lead acid battery only puts out 12 volts when it is nearly dead. In fact it is considered a dead battery at 12 volts as it will have very little amperage at 12V. A fully charged 12 volt lead acid battery is about 14.5 to 14.7V. So if you are using something other than a lead acid battery you should be shooting for 14.5 volts. I believe you could safely go to 16 volts, but no more.

And someone said that it is the amperage that supplys the power. Power is voltage x amperage and that is power in watts. Amperage helps more with the torque, and voltage more with the speed. If you want it to turn over worry about amperage, if you want it to turn over fast you need the amperage to get it turned over the first time and voltage to speed it up.

wcmorrison

My Feedback: (2)

Sport_Pilot is absolutely technically correct. However, it is not an altruistic world. Don't go down to the auto parts store and try and buy a 14.5 volt battery. I know that my 6 volt NiMh battery at full charge is really putting out 7.2 volts. In reality, condition of a lead acid battery (or any battery for that matter) has a lot to do with its voltage under load. It may initially have 14+ volts but under a load the voltage will drop and may drop radically depending on its charge state. Yes, Ohms law does say volts times amperes equals watts, a unit measurement of power. But you can not turn over an electric motor with watts, it must be within the realm of what is necessary to get it to move, a give voltage at a given amperage. As I said, a simple D cell can produce 25 amperes at 1.5 volts, or 37.5 watts for maybe a second or so. Often car batteries are referred to as to their cranking voltage, meaning how much it can tolerate being drawn out of it to get a starter (DC electric motor) to turn over. A weak car battery can still start an auto engine but it is an indication of its pending failure.

Thus the voltage of a battery is like its PSI in a water system, the push the water so to speak. The amperage out put is like the gallons per minute, the volume of water. Thus you can only truly test the condition of a battery when measuring the voltage under a load. You need both voltage and amperage to get an electric motor to run. Think of a battery as a large capacitor. It has a capacity to work and that is generally express in ampere hours or in our little batteries milliamperes per hour.

You can increase the capacity of the starter to work by increasing the available amperage at the rated voltage. Ergo, parallel batteries will produce more amperage at roughly the same output voltage. If you want the DC starter motor to turn faster increase the voltage. If you want it have more cranking power, increase the amperage.

So I have seen folks use old car batteries at the flying field. Not good enough to start an automobile but well adequate to start small engines. I have seen guys double up 7 ampere hour gel batteries to start bigger engines with ease. I am equally sure 3S lipos of high capacity, like 4,000 milliampere hours can start our large size engines with ease. I start my .91 sized alcohol engines with a 3S2200 battery and have to charge it maybe twice a season. Lots of capacity and lots of capability to generate short term high amperage for starting.