i have got a 96 f-150 4x4, i have got a stereo amp and some highpower acc. lights and i am wanting to switch to electric fan but the amp really draws the power, so i was thinking of switching from 12v to 24v and my main two concerns are 1- do i need to get a new alternator since i will be charging 2 batteries instead of 1 and my second concern is where am i going to mount the second battery. if anyone has ever done this or have any ideas let me know

 

Most of the time when people switch to 2 batteries, the batteries are hooked up in parallel, so the system is still at nominal 12 volts--positive to positive and negative to negative, like when you jump-start a vehicle with a dead battery. Hooking them up in series (chassis ground to neg of #1, #1 pos to #2 neg, #2 pos to system power) would result in the 24V system. You MAY need a larger alternator for the 12V dual battery, but not necessarily, as the biggest draw on vehicle batteries is on startup. I'm not sure what the rating on your year is, but I'm sure it's no less than 75 amps, and more probably 100 or so. (Standard on the '05 F150 is a 130 amp alternator). At 75 amps, you're looking at over 1000 watts to charge your battery(s) and run any accessories. Now if you're wanting to run some monster of a stereo system, then you'll just be making enemies in your neighborhood anyway.

To switch to a 24V system, you would have to make sure that anything electrical that you leave in the truck is only getting 12V, so that you don't run the risk of burning it up, or you would have to switch it to a 24V device. Think starter, computer, all light bulbs, your alternator (you can't charge a 24V battery with an 14ish volt alternator, it would be like trying to pour a glass of water with the glass above the pitcher).

Jason

 

jimbob21rc,
Go with a larger alternator. When running the truck operates off the alternator and will benefit from the extra oomph of a larger capacity alternator to drive additional components added to the truck. A dual battery 12V system is a great enhancement, I'd also reccomend an additional power distribution box. That way you leave the truck "stock" with the exception of the improved alternator, and derive a separate system to run your accessories from. This will make trouble shooting much easier also.

 

While I haven't done this yet in my truck... I will be doing this around the June or July timeframe, which is about when the new motor should be ready for installation.

I'll have two alternators, and two batteries.

The first battery and alternator will be wired as normal, part of the factory wiring system.

The second battery, will be charged by the second alternator exclusively, and provide power for all the high power accessories I'll be added to my truck, including air suspension (not for slamming in the weeds, but automatic ride control to make it more comfortable when unloaded, and air up for heavy loads and towing - its an F350 crewcab and the ride unloaded is rather harsh), the new audio system which is sitting in boxes in my garage, and various other things.

You can easily run two batteries in parallel, and charge of a larger alternator instead, but I chose to wire things up as two seperate systems, just because. I already have 460 ambulance brackets, pulleys and belts which provide such, so its more or less a bolt-in for me.

 

thanks for all the info, when isaid 24v system i wasn't thinking i really did mean dual 12v, all i have got is a 200w amp, i put that in just so i could here the radio better and get a little more bass tone, i don't blast rap real loud actually i listen to country most of the time and some rock, and with it up all the way you still can't hardly hear it out of the truck, and it has only got about 45amps running that is with the radio on,so maybe i just need a stronger alternator, i am wanting to put electric fans in and just needed to figure out how i am goint to power them, i would hate to be going down the road and my fans not kick in, that would be a recipe for disaster, one more question on electric fans-- do they make a dual fan system for my truck, it is a 96 150, i was thinking maybe not because of how deep the radiator is, but i haven't really checked into that yet.

 

I imagine that someone makes a pricy dual-fan setup for the F-series, but know that a full-size Northstar powered GM car has a dual-fan setup that fits well enough that if you can drill four holes, add a fuse, and splice three wires, you have a very inexpensive dual-fan setup.