How to Charge 24V Battery From 12V Alternator?

[mike]

Diesels run at 24v? Maybe the OTR trucks. Even our fire trucks are 12v systems.

There are smart alternators that are designed for lithium charging. That might be a good place to look. Otherwise the DC-DC converter. You are introducing losses with that. You can stack multiple DC-DCs from victron. They are nice little units but they aren't cheap.

No, usually the main system is 12v, but you could have more than one alternator to work a separate 24v system for other needs.

So its possible to buy/have-installed a 2nd alternator/generator on a standard hauling truck?   For example, if it was a Midnite Solar Classic charge controller, could one get a custom generator for 80v @ 50amp kind of thing powered by the engine?   That would get things up into a much higher level than say 12v @ 100a.

Yes, there are kits out there to install 2 and 3 alternators in one car/truck. You would just need the kit and an appropriately-sized belt. There are people doing it for their crazy subwoofer audio systems lol.

[Crimp Daddy]

Diesels run at 24v? Maybe the OTR trucks. Even our fire trucks are 12v systems.

There are smart alternators that are designed for lithium charging. That might be a good place to look. Otherwise the DC-DC converter. You are introducing losses with that. You can stack multiple DC-DCs from victron. They are nice little units but they aren't cheap.

No, usually the main system is 12v, but you could have more than one alternator to work a separate 24v system for other needs.

So its possible to buy/have-installed a 2nd alternator/generator on a standard hauling truck?   For example, if it was a Midnite Solar Classic charge controller, could one get a custom generator for 80v @ 50amp kind of thing powered by the engine?   That would get things up into a much higher level than say 12v @ 100a.

Its pretty common in the car stereo world... it drives off a belt, so creating a separate 24v system should be pretty easy.

[OffGridInTheCity]

Diesels run at 24v? Maybe the OTR trucks. Even our fire trucks are 12v systems.

There are smart alternators that are designed for lithium charging. That might be a good place to look. Otherwise the DC-DC converter. You are introducing losses with that. You can stack multiple DC-DCs from victron. They are nice little units but they aren't cheap.

No, usually the main system is 12v, but you could have more than one alternator to work a separate 24v system for other needs.

So its possible to buy/have-installed a 2nd alternator/generator on a standard hauling truck?   For example, if it was a Midnite Solar Classic charge controller, could one get a custom generator for 80v @ 50amp kind of thing powered by the engine?   That would get things up into a much higher level than say 12v @ 100a.

Its pretty common in the car stereo world... it drives off a belt, so creating a separate 24v system should be pretty easy.

WOW!  Fantastic - I Love It!   I'm looking at starting a custom cargo trailer project in 2020 and of course I'd like to set it up with massive battery and PV array and inverter and ...       A little tiny Victron 12v -> 24v 50a just won't cut it.      I...   want....  power...  and this picture looks exactly like the right approach

[Jim-C]

I considered installing a 24v alternator. I would still need a DC to DC converter to maintain the proper steady output voltage.
I'm going to get 4 Orion 12 to 24 with 30 amp output.

Thanks for the replies.

[camthecam]

I wonder if you had a custom regulator to just lift the field windings and trick the alternator to put out what you want. Rectifier pending of course.

[howdy]

It should still work but at a slower rate.

[OffGridInTheCity]

Based on above I found 12v and to a lessor degree 24v 'second alternator' kits and it looks like they need some kind of regulator. And I'd really like to stay with a 48v lithium ion battery bank so its compatible (my packs are transferable) between my home version and my custom RV.

A while back, for my home battery bank, I bought several 750watt 48v (lithium-ion voltage oriented) chargers from ebay.com. They are on a power strip to turn on 1 or 2 or 3 or 4 etc... (I can control the wattage devoted to charging) and output hooked directly to the battery bank. This lets me use my home generator to charge my battery bank to feed power into my system.

So maybe a similar setup for a 12v or 24v alternator -> 120v inverter and then run a standard 120v based 24v or 48v chargers. I understand there are losses - maybe as much as 20% ? in this scheme - but it might simplify trying to find specific battery bank regulators etc and this would scale up to max the alternator can put out.