It is true the 24v system is just two 12v batteries, and you can try to jump just one side w/ 12v, but have you ever tried with much luck!! dont sit there and tell a guy he's an idiot just because you dont have to deal with the situation he is in. It is very annoying trying to jump a 24v system with 12volts. it takes time to try to charge each battery. If you could just jump the starter it would save alot of time if you have weak batteries or if something got left on. There are alot of 24v systems in use. heavy equipment is very common. Not just old ones.

edit: I found the website for the system being discussed. Looks like a nice setup. http://www.oxion.net/super_boost_kit_12-24.htm

 

I am a retired heacy equipment mechanic and have jumped 24v systems many times with my truck with 12v
my truck had two 30H batteries and with separating one battery and using two sets of good cables normally had no problems
if I had to be in a hurry would just hook my portale welder to it

BTW my cables were made from #4 welding cable not wally world specials

 

Miker67 That is a very cool set up. What gauge metal can you weld1/8 i'm thinking?

 

no, you cnt do that with your truk. it is a 12 volt system. the 2 batts are there to get more power, not higher voltage. you would have to wire them in nseries and that is impossible to do when they are in parrallel

 

G Bobka, since since the thickness of metal you can weld is tied to penetration, and penetration is tied to amps, then this welder in theory can weld up to 1/2 inch to 3/4 inch thick metal because it is rated up to 350 amps @ 36v. Now that is a monster welder by any standards and I was skeptical at first, but it is a good little unit. It is decieving because of its small size, but if you think about it, the majority of your standard welding machine's size comes from the power transformer that is used to convert from AC to DC. In this instance, the power doesn't need conversion and all you need is a pair of batteries. Getting your welding current straight from a DC battery is kinda like taking beer straight from the tap.........smooth and fresh. I haven't welded 3/4 inch with it, but 3/8 @24v is really nice.

 

i work for a large mass transit company here in philadelphia. most of our buses have the detroit series 50 engine. the starter and most of the rest of the bus runs on 24 volts. the lighting still runs mostly on 12 volts. our newest buses have the cummins engines in them. they are the same way. 24 volt starter, and most of other modules are 24 volt. a couple are 12 volts though. the series 50 and the cummins would never even think about cranking 1/100 of a turn if they only had 12 volts. we also run 4-1000 cca batts wired up to give us both 24 volts from one of the cables and 12 volts from the other cable.

 

Thus the reason for the switch the original poster talked about!!

 

I never realized anything but construction equipment still used 24V systems,but with a 24V charging system should be an easy and trouble free system
not having to deal with an aggrevating series-parallel switch which was about as dependable as the GM starter solenoid of the time

 

you can jump start 24 volt system with a 12 volt system. you are stil mixing up the fact that these vehicles still have 12 volt systems and thats all they need to bring their batterys up to supply the strted with 24 volts through a series parralle switch. i worked on trucks since i was a kid and had nothing but 24 volts starters until i got my 1980 600 hp kta cummins and that monster 1150 cubic inch diesel had a 12 volt starter. it was at least twice the size of a mt-40 starter. but it started that kta for 1,400,000 miles. i have a question, why would you want to convert a psd t 24 volt? i have seen 36 voltaircraft and other odd ball voltage in them too, but thats another world away from trucks. and why would you try to jump an engine by connecting directly to a starter. if the starter system uses 12 volt batterys, you jump it with a 12 volt. years ago i built up a 331 caddy that never had a 12 volt starter made that would fit it and in the cold it just wouldnt crank. i got a series parralle switch and rigged 2 6 volt batterys and threw 12 volts toit and it always started instantly. but you never dared let it crank for more that 2 or 3 seconds for fear of burning the starter. i never burnt a starter. i did get the batterys down once and we jumped it with a 6 volt flathead ford pick-up.

 

Because, depending on the size of the truck, it's easier to get a jumper cable to the starter than it is to get the battery box covers off

 

Don't you mean... 2 banks of 12 volt batteries that are "put" (wired) in SERIES by the switch that sends 24 volts to the starter???
Now who knows & does not know what they are talking about!

 

Nice necro post - you're talking trash to a post from 2007...

 

In all honesty I got so caught up in reading it I never even noticed / looked at the date.
But you must admit, I was a good catch of a mistake the self proclaimed highly experienced oltrucker made!
PS: YOUR responding as well in a Dead Thread. Or have I caused a Lazarus effect here?
Is there a rule against posting & supplying details to correct errors you find when reading a thread?

 

I tried to weld using two batteries wired in series.. did it correctly pet youtube school….rods kept melting…glowed like a light bulb filament.

no…don’t try to jump start a 12v vehicle with 24v by wiring batteries in series.