Alternator-Powered Skeet thrower

[soopergenious]

Hey guys (& gals)-
I'm new here, and wanted to get the input of people who have some experience with this. Currently, at my range, we use solar-recharged deep cycle 12v batteries to run the skeet throwers. However, the batteries are almost all dead (around 6 years old), and cost around $200 a pop. Rather than continue to invest in this system, would it be possible to power each 12v thrower with a small engine->v-belt->alternator setup? I can purchase a brand new 100a alternator for around $80, and a 6HP engine for around $90. What would be the benefits/ detriments with this system? I know that we would have to pay for gas and oil, however that should be fairly negligible considering we will only shoot a few hours a week. The motor on the thrower says 40a current on it, and the current batteries are rated for 100ah, if that helps.
I feel kind of bad posting something totally not tractor-related for my first post, but wanted to hear y'alls thoughts. Mods, please feel to move this to whatever catagory would be best, as once again, I am a noob and have very little idea of how to file stuff and what not. It took me 15 minutes to just figure out how to start a new thread-- I am much better with mechanical and electrical engineering than I am with using forums.
Thanks again
Jimmy

 

[dave1949]

Welcome!

Never tried it, but I wonder how well the alternator will react to quick load changes. I assume the 40A thrower motor is not a constant load, and represents a possible peak draw when a skeet is thrown?

I think of automotive alternators as charging the battery, and the battery supplies the load in combination with the alternator. With no battery involved, I am not sure how it would react to a fast load ramp-up.

The engine noise could be a nuisance when not shooting. A cheap engine could be a cranky to start engine, no fun.

 

[DT86]

Personally if I already had the solar set up I'd probably stick with it. I just put together a solar set up for a fence charger using the biggest deep cycle battery I could find and the battery was closer to $120 than $200.

How many thrower set ups do you have?

 

[DT86]

I think of automotive alternators as charging the battery, and the battery supplies the load in combination with the alternator. With no battery involved, I am not sure how it would react to a fast load ramp-up.

The engine noise could be a nuisance when not shooting. A cheap engine could be a cranky to start engine, no fun.

Yeah I was going to add that but you beat me to it!

 

[broadway3000]

I think you would quickly get annoyed with the constant noise of the generator. Besides that I think you would still have to run at least 1 battery to hold power because of the 40 draw.

 

[soopergenious]

Thanks for the replies. We have 5 stations running off of batteries. The solar system is broken on some of them, and will need to be replaced soon on the others. We do have 110v power available a hundred yards away or so, however we would have to purchase independent transformers for each thrower as they are in a 5-stand setup. Does anyone have an idea that does not require the use of solar, yet is still relatively cost effective? I believe we only have 15 watt panels, and once we start to use the range again, I doubt they will be able to keep up. Also, each battery is almost twice the size of your average car battery (these are 100ah) and also weigh around twice as much-- not fun to carry around. Is there any type of alternator system that would be able to handle the sudden 40a surge? The noise will not be an issue- especially with ear plugs when shooting. Thanks again for all the replies.
Jimmy
PS: DT86- where do you buy batteries? The cheapest 100ah's I could find were on eBay and still cost around $180. $120 would be fantastic if you could point me in the right direction.

 

[Biggreenavalanche]

I'd go ahead and transition to 110/transformer set up...think you'd be a lot happier with that in the long run...flippin a light switch beats fueling, starting, exhaust, and noise of small engine and is probably a lot more dependable than either the curren set up, or the proposed setup...just my :2cents: worth.

Rich

 

[aczlan]

So you are talking about spending $190/station to add a gas engine and there are five stations, so $950 and power is 300' away.
Lets see:
$422 400' of 12/3 UF
$12 2 x space 4 circuit breaker box
$16 2 x 20 amp breakers
$20 Boxes/Outlets
$500 5 x 40 amp 12v chargers
$969 Total
Just use your current batteries or if needed get some new ones.
More realistically, I suspect that your machines don't draw 40 amps except for possibly a half second when the skeet is actually being thrown (this could be verified if we had the make/model of if you checked with the manufacturer) , so you could get cheaper 10 to 20 amp chargers and buy a couple of new batteries.

Edit: Looks like the RC community has found a way to re-purpose old server power supplied to get 30+ amps at 12VDC, so if you or someone at the club is good with soldering and wants to eliminate the batteries without spending hundreds per station on power supplies, see http://www.rcgroups.com/forums/showthread.php?t=1005309 or http://www.rcgroups.com/forums/showpost.php?p=17731408&postcount=491

Aaron Z

 

[soopergenious]

Thanks Aaron. I will definitely look in to that. The farthest thrower is another 25 yards or so away, however that should not be too much trouble. If we didn't have to worry about batteries, that would be great. Where are you sourcing the transformers from? Thanks again.

 

[aczlan]

Where are you sourcing the transformers from? Thanks again.

For battery chargers, I just searched for 40 amp battery charger. For a 12 volt supply the sites I linked to had directions and sources, but it appears that there are those selling them on Ebay for under $50: RC Power Supply 575 Watts 47 Amp 100 240V AC to DC 12V Efuel CB 20 30 40 50 60 | eBay At that price, I would just get power supplies and eliminate the batteries altogether.

Aaron Z