I have an 05 cummins, so thats two batteries, then another battery on my sa-200. So I was thinking about running cables from the truck to the machine to lose a battery. Has any one done this? Good idea or not?
What is the purpose for this ?
Hello J-rod, if you're thinking of doing this to save on the hassle of having to worry about 3 batteries I'm sure that it would work. I would use a battery switch to disconnect the welder from the truck's batteries when you aren't using it. These types of switches are commonly used on older greyhound style busses and different types of farm equipment. I don't believe I would use an isolator switch in your proposed system because you may run the risk of "using up" one of the batteries so to speak. It is always good to use and replace battery pairs as a matched set. If your truck is under warranty I would first see how your proposal might affect the coverage. As far as wiring it goes, you could connect your main + cable to the termination point on your trucks batteries where both of the + cables attach to the main starter stud or solenoid stud(sorry I'm not familiar with the Dodge wiring schematic). Then run this cable to the on/off switch and from there to the starter on the SA 200. Next connect a ground cable from the welder to a good connection point on the frame of your truck, routing it in the best manner and to the closest point near the welder. Not really necessary to go all the way back to the battery ground on the truck. Definitely check on any warranty issues with your truck before going ahead with any wiring changes. Best regards, aevald
The question is, Is it worth the hassle to lose one group 24 battery?
J-Rod
The alternators might not get along with each other if the truck and welder are running at the same time. The one on the 05 Dodge is 136 amps and $200.00. The one on the SA-200 is 30 amps and $30.00 (at least the one on mine is). This could be a big headache over a $60.00 battery for the welder.
"I don't know anything and have a lot people lined up and willing to swear to it just in case."
I've seen this done but the truck was a gas motor and the machine was a sa200, it worked real good.
This is a little off topic but I knew a guy that his machine would run off the fuel in the truck.
LOL!! i like your closing comment
I wouldn't mess with it either. For the want of saving a battery, you may end up stranded by a dead one in the truck. Or burn something up like J rod mentioned. wouldn't risk it. Don't know, just a thought.
"You lie, I'll swear to it...." ( Something a friend used to say.) Nice. :-) S.W.
Well, it'll probably cost you more than a new battery for the sa200, but you would need:
1) a large cable (2 gauge or thicker would probably be best, 4 should work, but 6 is certainly too thin)
2) a massive diode (think 500A or more rated, like something someone would use to rectify an A/C welder). This would prevent current from the sa200's alternator from going back to your truck's batteries, should the sa200 be running at the same time as the truck.
Between today's cost of copper, and at least $40 for a diode on eBay, its probably best to just keep a set of jumper cables around, and think of each battery as a backup for the other.
I have 2 alternators on the engine in My boat. Normally they charge different battery banks. When I combine the banks the only problem is that the sophisticated multi rate regulator on the house bank "sees" the voltage from the other alternator, and goes to float voltage prematurely.
With 2 fixed voltage regulators this interaction will cause the alternator with the lower voltage setting to have no output any time the system voltage excedes its voltage setting.
I strongly suggest that You don't run an laternator that is not connected to a load [NOT JUST INSTRUMENTATION]. Residual magnetism can sometimes create high enough voltage to fry the diodes or instrumentation on the engine. A solid state device that functions much like a ziener diode is available to protect from this problem, it goes from the alternator output to ground.
Thanks for every ones input, just something that I have thought about, not just set on doing it.
Forum
