12v winch on 24v system

[rtadams89]

I acquired a military truck recently that has a 24v power system. The previous owner mounted a electric lift/winch in the back which is rated for 12 volts (StrongArm brand) and center taped the two truck batteries to get 12 volts for it. I'm not too keen to keep it that way out of concern for getting the batteries out of balance, particularly since I plan to be using this lift/winch quite a bit. The winch draws 70 amps (840 watts) at full load.

I've come up with a couple of options:

1) Get a 80 amp rated 24v-12v step down converter for $90 and call it good. My concern with this is that the way the wiring is currently run, the converter would always be powered but I don't want it to drain my main batteries.

2) Get several lower amp rated 24v-12v step down converters and connect them in parallel. Can these actually be connected in parallel to supply more current?

3) Get a single 30 amp rated 24-12v step down converter and use it to charge a deep-cycle 12v battery which in turn would power the winch. My concern with this one is if the step down converter can be used to charge a battery and if it will have any issues having a power source instead of a load on the 12v side?

4) Continue center tapping the batteries to power the winch, but add a battery equalizer (something like https://www.amazon.com/gp/product/B01JJ3UKDU/) to keep the main truck batteries balanced. Concern here is how the equalizer will respond to a 70 amp draw at the same time it is trying to keep the batteries equalized.

At present, I am leaning towards options #3 followed by option #4. Thoughts?

 

[papakb]

Don't mess around when it comes to power circuits in your truck or your asking for trouble. Center tapping batteries is a perfect example of this. Your best bet is to either buy a voltage dropping converter but you want to use something rated at least 50% over the expected draw for safety. Personally I like the Vanner converter/battery maintainers for things that draw large amounts of current like winches.

Kurt

 

[Chief_919]

A better option than all those, and the one I would go for, would be to add a separate 12v system with an additional battery and alternator. Without knowing what kind of truck you are talking about its hard to say how hard or easy that would be, but in general its not too bad to fabricate a mount from junkyard parts and add a one wire alternator like this one.

 

[Suprman]

Motors have a large startup draw and don't work well thru power converters. I would look for a replacement 24 volt motor for the winch. Prob the easiest and most reliable way to go.

 

[pjwest03]

In the electric vehicle world with high voltage drive systems, they still tend to keep a 12v battery on board and use a DC/DC battery charger to keep it topped up.

Example of a 24v - 12v charger: http://www.powerstream.com/DCC-2412.htm

 

[gimpyrobb]

Just power the winch with 24v. You will probably need to swap out the 12v solenoids, but it will work fine on 24v. I've done it plenty of times.

 

[rtadams89]

I ended up doing a bunch of electrical work for other reasons. For the winch, I ran a 24v 4 gauge line to the back of the truck with a manual reset shortstop between the battery and the cable. That cable connects to a 24v-to-12v converter rated for 85amps continuous which then powers the winch. So far that seems to work fine, and also gives me a convenient 12v source at the back of the truck.