# Battery Powered Start Conversion?



## Sblg43 (Jan 18, 2014)

Just wondering if there might be a way to convert an AC starter to DC.

I have a friend who put a Harbor Freight 13HP engine on a snow thrower and that engine has a DC starter. So he mounted a battery onto the unit and voila, turn key starting for his snow thrower.

Without having to buy a $360 engine and retrofitting it like he did, is there a simpler way to mount a 12V battery and make it work with the AC starters that are on most of the US made snow throwers out there?

I didn't look too deep, but maybe there is already a thread on the forum about this topic. (Found one that is very old)

When I am doing my snow removal accounts, it would be beneficial to turn a key and go!


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## Sblg43 (Jan 18, 2014)

A plan is starting to gel.

It has to do with a 12V lawn tractor battery and a power inverter from Harbor Freight........

Probably should find out how much amperage is needed for the starter on the snow thrower. I would guess, less than 15 amps.

But now, another thought, put an inverter in my truck and just plug an extension cord from the truck to the snow thrower that will be on the trailer right behind it. That would be easier than having another battery to maintain.


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## Sblg43 (Jan 18, 2014)

Well, son of a gun, if I didn't just find something...

It never dawned on me to look for a 12V starter for a Tecumseh engine. But dang, Amazon has them and they can be bundled with a push button and a starter solenoid as well.

This might be a fun little project - to make a push button start snow thrower!

https://www.amazon.com/Starter-Tecumseh-HM100-AM30931-33202/dp/B0094JILU4

Is there an Ari P on this forum? He has some youtube videos were he describes a bit on how he converted his units to battery start.


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## Waterlooboy2hp (Nov 29, 2011)

Sblg43 said:


> A plan is starting to gel.
> 
> It has to do with a 12V lawn tractor battery and a power inverter from Harbor Freight........
> 
> ...


===========================================================


 I happen to be in the same church right now, but sitting in a different pew. ----- In my case, I am working with a Kohler k141 engine. 


 I found and ordered a NOS 12v starter for it yesterday. For power, I am going to just use one of those 3in1 jump starters, like the one that HF sells.

 I will make and put a small terminal box on the blower for clipping the jump cables on. For a push button, I plan to just use one of the old starter switches, like the ones used under the gas peddle on many old cars. Not planning on keeping the jump starter on the blower. ---- John


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## RedOctobyr (Mar 2, 2014)

Sblg43 said:


> Well, son of a gun, if I didn't just find something...
> 
> It never dawned on me to look for a 12V starter for a Tecumseh engine. But dang, Amazon has them and they can be bundled with a push button and a starter solenoid as well.
> 
> This might be a fun little project - to make a push button start snow thrower!


Your plan evolved quickly. But yeah, I think buying a 12V DC starter is much more practical than trying to change things about the existing starter motor, or adding an inverter. 

The idea of using a jump pack as your power source is interesting. But if the goal is to be able to start it anywhere during use, rather than just for the initial start to begin clearing, I think an onboard battery would be an easier solution during use. 

Though you'd want to look into whether your engine has an electrical output that's suitable for charging a starter battery. If not, then yeah, maybe a jump pack is better, since that would already have a means to charge itself.


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## Kiss4aFrog (Nov 3, 2013)

12 volt starter is the way to go. There are a few of them running around, mostly Honda, some of the larger Ariens come to mind. I have a stock 1030 Snapper that has a 12 volt system and all the 12v parts are listed in the manual. I like it because I'm getting old and tugging on that cord when it's sub zero just isn't getting any easier.


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## cr4west (Jan 10, 2017)

Use a 12v batery and starter setup from a similar powered garden tractor or riding mower. An inverter setup would need a huge power capability to handle the 110v AC starter start current. Besides I see a lot of people returning those inverters at HF so don't waste your time on one of those.


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## jsup (Nov 19, 2017)

Waterlooboy2hp said:


> ===========================================================
> I happen to be in the same church right now, but sitting in a different pew. ----- In my case, I am working with a Kohler k141 engine.
> 
> I found and ordered a NOS 12v starter for it yesterday. For power, I am going to just use one of those 3in1 jump starters, like the one that HF sells.
> ...


A relay and small switch may be easier to do. It's easier to wire, keep all the heavy wires close to the starter, and just run a couple small wires to the dash using a momentarily on switch. One of those five pin Bosch relays are cheap, plentiful. Del City sells sockets for them to make the install easy. HELLA makes waterproof ones, which is the one I'd look for.

Or a high current horn button for a boat. Something like this:










Or maybe better this, it's sealed, high current switch:

https://alexnld.com/product/waterpr...on-start-starter-car-interior-switch-control/


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## Waterlooboy2hp (Nov 29, 2011)

jsup said:


> A relay and small switch may be easier to do. It's easier to wire, keep all the heavy wires close to the starter, and just run a couple small wires to the dash using a momentarily on switch. One of those five pin Bosch relays are cheap, plentiful. Del City sells sockets for them to make the install easy. HELLA makes waterproof ones, which is the one I'd look for.
> 
> ===============================================================
> 
> ...


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## jsup (Nov 19, 2017)

Waterlooboy2hp said:


> jsup said:
> 
> 
> > A relay and small switch may be easier to do. It's easier to wire, keep all the heavy wires close to the starter, and just run a couple small wires to the dash using a momentarily on switch. One of those five pin Bosch relays are cheap, plentiful. Del City sells sockets for them to make the install easy. HELLA makes waterproof ones, which is the one I'd look for.
> ...


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## Kiss4aFrog (Nov 3, 2013)

That relay and socket are available through walmart for $4 shipped: https://www.walmart.com/ip/QTY1-REL...WATERPROOF-DELCO-C1754A-REPLACEMENT/661986794


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## Waterlooboy2hp (Nov 29, 2011)

jsup said:


> Waterlooboy2hp said:
> 
> 
> > Manual compression release. That's new to me. What is that?
> ...


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## jsup (Nov 19, 2017)

That's one mean looking machine. What's the green one in the Avatar to the right. Looks like the same machine in a different color.

What was the thinking behind the compression release? To make it easier to pull start?


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## Waterlooboy2hp (Nov 29, 2011)

jsup said:


> That's one mean looking machine. What's the green one in the Avatar to the right. Looks like the same machine in a different color.
> 
> What was the thinking behind the compression release? To make it easier to pull start?



===========================================================


Yes, the compression release takes the strain off a pull start, as well as an electric starter motor.


The machine in my avatar is also a 3 stage machine. However, it is a 1974 26" American Lincoln Sno-Mow. Except for the matching up & down augers, The rest is completely different. It has also had many modifications done to it. --- You can remove the blower with just 2 bolts and hook up to a rotary mower. I am only aware of 3 others on the entire internet. ---- John


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## RedOctobyr (Mar 2, 2014)

jsup said:


> What was the thinking behind the compression release? To make it easier to pull start?


Typically. Most engines now have automatic compression releases, so they're doing it for us behind the scenes. 

If you want to see what it would feel like without the compression release, with an OHV engine, increase the valve clearance on the exhaust valve to maybe 0.020" or so.


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## crazzywolfie (Jun 2, 2014)

i just thought i would point out that using an inverter to run the electric starts is not advisable. i know unless you buy a pure sine wave inverter which are very expensive it can cause issue with the motor. i know i have run motor on modified sine wave inverters and something always seems off about them when running.


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## jsup (Nov 19, 2017)

RedOctobyr said:


> Typically. Most engines now have automatic compression releases, so they're doing it for us behind the scenes.
> 
> If you want to see what it would feel like without the compression release, with an OHV engine, increase the valve clearance on the exhaust valve to maybe 0.020" or so.


So it's done with valve overlap? Interesting. On a car you just retard the timing for starting to make it easier to turn. 

Learn something new every day.


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## jsup (Nov 19, 2017)

Waterlooboy2hp said:


> ===========================================================
> 
> 
> Yes, the compression release takes the strain off a pull start, as well as an electric starter motor.
> ...


Very cool.


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## RedOctobyr (Mar 2, 2014)

Not valve timing overlap. There is usually a feature on the exhaust camshaft that bumps the valve open slightly at low RPMs, like when pull-starting. This vents some of the cylinder air to the exhaust, reducing the pressure that you're fighting. 

This is at least part of why there is a specific range for valve clearance, like 0.004-0.006". Let's assume the compression release bumps the pushrod by 0.015", so that clearance range would open the valve by 0.009-0.011". 

But make your valve clearance too large, like the hypothetical 0.020", and the compression release doesn't do anything. The compression release bumps the pushrod by the same 0.015", but with 0.020" of clearance, it's still 0.005" short of actually opening the valve. So the cylinder stays sealed up tight, and the engine is very hard to pull by hand, and the electric starter may not be able to manage it. 

This just happened to a friend's machine (OHV Briggs), it became very hard to pull, and the electric starter couldn't do it. He checked the valve clearance, found it was too large, re-set it properly, and now it's easier to start again. 

Incidentally, you also don't want your valve clearance too *small*, because then as the engine gets hot, the valve won't actually close fully during operation. You'll lose power, and can also burn the valve, and the seat.


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## Kiss4aFrog (Nov 3, 2013)

Here is the wiring diagram for how they get hooked up. This is taken from my JD rider as they are known to have issues with the starter not working and it's a result of all the safeties causing a loss of current to properly kick in the solenoid. They will just click like the battery is low or the starter is bad.


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## jsup (Nov 19, 2017)

RedOctobyr said:


> Not valve timing overlap. There is usually a feature on the exhaust camshaft that bumps the valve open slightly at low RPMs, like when pull-starting. This vents some of the cylinder air to the exhaust, reducing the pressure that you're fighting.
> 
> This is at least part of why there is a specific range for valve clearance, like 0.004-0.006". Let's assume the compression release bumps the pushrod by 0.015", so that clearance range would open the valve by 0.009-0.011".
> 
> ...


OK, I get that. But how exactly does it STOP bumping the valve slightly after starting? Is it centrifugal? What's the trick?

Thanks.


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## RedOctobyr (Mar 2, 2014)

I believe it's centrifugal, yes. 

This is a brief video showing how it works on a Briggs OHV, it's a centrifugal mechanism.


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## jsup (Nov 19, 2017)

Thanks. Looks like a predecessor to VVT engines. They work off oil pressure, but still, similar theory. It's elegant in its simplicity.


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## AdrianZ (Nov 29, 2018)

Sblg43 said:


> Just wondering if there might be a way to convert an AC starter to DC.
> 
> I have a friend who put a Harbor Freight 13HP engine on a snow thrower and that engine has a DC starter. So he mounted a battery onto the unit and voila, turn key starting for his snow thrower.
> 
> ...


Hi: No easy way. A few makes of snow blowers, tillers and the like have a DC starter motor available but they are expensive. Mostly they are AC starter motors. Due to family operating concerns (not able to pull start, or unreel 50ft of power cable if snow blower stalled away from the AC power outlet). I am currently building a portable AC starter kit using a Harbor Freight Viking Lithium 12v DC Starter battery and a 1000W (2000W Peak) inverter. The unit hangs in a tool bag from the snow blower frame and has a 110V plug that is left plugged in only while snow blowing. When snow blowing finished battery/inverter unit must be removed and place in a dry location, charged, and made ready for next use. 
Adrian Zeffert
2028 Troy Bilt Storm Chaser 2690XP (tracked)


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## RedOctobyr (Mar 2, 2014)

Wow, that's an interesting approach! Please let us know how it works out. Needing to go through an inverter to solve the problem is unfortunate, but hopefully it will work out well! 

I have no idea how many watts my electric starter draws, though the garage lights dim slightly. But I have a Kill-A-Watt, I could check, if that was useful info (you may have already measured this for your machine).


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## crazzywolfie (Jun 2, 2014)

i tried something similar last winter and it never worked. the inverter didn't seem like it had enough to really crank the engine. i have a feeling it might have something to do with needing a pure sine wave inverter since motors and standard inverters don't really get along. i have run a grinder off my inverter but it didn't really feel right.


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## Kiss4aFrog (Nov 3, 2013)

The starter motors on our Tecumseh, Briggs, Predator, ... engines are basic electric motors and don't need a pure sine wave inverter. Those are needed for things that are more electronic and finicky about getting true AC or DC. Supplying power to the starting motor is like throwing a baseball through a big hoop. It doesn't need to be exactly in the center where running a heart monitor or a electronically controlled variable speed motor needs to be right in the center consistently.

The problem with trying to convert 12v DC to 120 AC is that it's a big jump to supply the amps (watts) that starter motor needs to crank the engine. I know on a small rider (12-15hp) it'll pull 50+ amps. Even at half that a 1K inverter won't come close.
If you're going to go with on-board starting best to just get a 12 volt starter. Usually they are fairly cheap anyway.

But you never know. AdrianZ my math might be off, if it works would love to hear about it.

.


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## RedOctobyr (Mar 2, 2014)

Kiss4aFrog said:


> The problem with trying to convert 12v DC to 120 AC is that it's a big jump to supply the amps (watts) that starter motor needs to crank the engine. I know on a small rider (12-15hp) it'll pull 50+ amps. Even at half that a 1K inverter won't come close.
> But you never know. AdrianZ my math might be off, if it works would love to hear about it.



But don't forget that you need to consider the load in terms of watts, not amps, since we're talking about 2 different voltages. A small rider pulling 50A is doing that at 12V, not at 110V. And 50A * 12V = 600W. 

So it would be drawing a little over half the capacity of a 1000W inverter. And the one in question is 1000W continuous, 2000W peak. It could briefly supply 165A at 12V, per the specs, if it had enough input power from the battery. Hopefully it will have enough oomph.


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## Kiss4aFrog (Nov 3, 2013)

I agree with you.
That's way I was saying my math might be questionable. There is also the loss in the converter. The cheaper the converter the higher the loss. Just too many variables for my little brain to calculate so I really am curious how Adrian's creation turns out.
For me it's easier to go with a 12 volt starter, battery, relay and switch. BUT if a 12 volt starter isn't available than this franken-inverter might be the way to go.

.


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