Combination 12V and 24V system

[scotts90ranger]

We have a customer at work that wants to use a 24V transmission with one of our engines that needs to run on 12V, it's on a forklift (bigger one) so not a lot of spare space for dodads... Apparently a common way is to run 3 batteries and two alternators which they would like to avoid if possible.

Google is near useless anymore with all the content out there and ads, so I'll ask where I know some people... nearly everything I've searched for ends up with questions about trolling motors on a boat which is completely different...

The transmission on 24V is most likely a light load with a few solenoids and control panel so a couple amps continuous if I had to guess. The engine on 12V will have around 8A continuous tops other than the large load at start.

What would the likelihood of success if we ran a 70A 24V alternator with a 27V regulator with two batteries in series with the engine on a center tap? Going to a 24V starter would probably help battery life but I'm pretty sure this would work decently...

Thanks!

 

[RonD]

Why not just use a Step up transformer, 12v to 24v, not uncommon in industrial applications or in Marine applications

Especially if the 24v is a lower draw

Marine application seen here: https://dcpoweronboard.com/12-to-24v-step-up-converters/

Non-isolated would be fine since I would assume 12v and 24v would share a common ground reference

 

[ericbphoto]

That converter looks like a good solution. Transformers don't work on dc.

 

[scotts90ranger]

That does sound reasonable... and also means nothing has to change on our end .

 

[scotts90ranger]

Ok, apparently they tried a voltage converter and are wanting to go the full 24V route where possible... I guess the converter killed the batteries quickly.

 

[RonD]

That would seem odd to me, transmission needs 24volt when engine is off?


Then do the dual 12volt batteries in series and 24v alternator, AND 24v starter<<<biggest AMP draw
Then step down transformer to power other 12volt devices
You could "tap" first battery's positive to get 12volt, I like the 24v/12v transformer better

 

[bobbywalter]

That would seem odd to me, transmission needs 24volt when engine is off?


Then do the dual 12volt batteries in series and 24v alternator, AND 24v starter<<<biggest AMP draw
Then step down transformer to power other 12volt devices
You could "tap" first battery's positive to get 12volt, I like the 24v/12v transformer better

I did similar to this for a bit to start my truck with 24 volts.

I have the military dual alternator setup for the engine to charge each battery seperate...but wasn't going thru all of that....and the big step down critter

I had a hot start issue with a shitty 12v starter... I just parallel switched the starter and isolated the alternator when cranking....and all of my truck stuff just pulled off of one battery.

Worked...and got me by

Now I run a powermaster starter and direct ground to the alternator to keep the batteries charging high enough....they were only charging 13.3. but those powermaster starters are 350 bux or more...so I was nervous the first 2 years.

 

[Robertmangrum.rm]

I know on our buses that the battery system is 24v and they use an equalizer to run all the 12v powers do dads. Seems to be a pretty good system.

 

[scotts90ranger]

I didn't ask why they had the converter on with the key off... the guy that told me I've dealt with for years and I'm pretty sure he'd be smart enough to figure that out... We're dealing with a GM 350 so a 24V starter is probably available... I'll look into an equalizer, running one of those only on key up to not kill both batteries (I read something they put a load on the high voltage battery which would make sense...), that would make sense and be fairly simple.

The forklifts I deal with are goofy, some are ran thousands of hours a year, some 20 hours a year, you never know, and it's amazing at how "smart" some "mechanics" are that work on stuff... I've dealt with diesel engine mechanics that don't know what a spark plug is...

 

[snoranger]

I didn't ask why they had the converter on with the key off... the guy that told me I've dealt with for years and I'm pretty sure he'd be smart enough to figure that out... We're dealing with a GM 350 so a 24V starter is probably available... I'll look into an equalizer, running one of those only on key up to not kill both batteries (I read something they put a load on the high voltage battery which would make sense...), that would make sense and be fairly simple.

The forklifts I deal with are goofy, some are ran thousands of hours a year, some 20 hours a year, you never know, and it's amazing at how "smart" some "mechanics" are that work on stuff... I've dealt with diesel engine mechanics that don't know what a spark plug is...

Why would a diesel mechanic need to know what a spark plug is?!?!

 

[Robertmangrum.rm]

Why would a diesel mechanic need to know what a spark plug is?!?!

To make flames shoot out the exhaust haha

 

[scotts90ranger]

True, but why is a diesel mechanic working on spark ignited equipment and arguing about what a spark plug is? Why did my ears hear the sentence "it'll crank but it won't crank"? I've heard some doozies but I don't remember them all now...