How can I add a 12 v Alternator?

[reblawyer]

I have searched the threads and can't find anything addressing this question. I would like to add a 12 volt alternator to my truck and was wondering if anyone had any suggestions or ideas on getting that done. Thanks for any input.

 

[MrAugust]

why on earth wud you want to do that?

 

[mangus580]

To add 12v Accesories of course

 

[abh3]

I'm far from a Duece expert but on heavy equipment we just run a wire, WITH OVERLOAD PROTECTION like an appropriatly sized breaker, off one 12v battery in the series positive post to a little fuseblock (I like the ones for boats, they're tougher),then through switches and on to the various devices. The ground is similarly arranged, with a little terminal block and then back to that battery.This way I have 12v driving and flood lights (cheap!) and a radio on a 24v machine. I see no reason this wouldn't work on the Duece though the radio would have to be a THUMPER to be heard over the engine racket!!!

 

[reblawyer]

I'm wanting to get more amps nad would like to seperate my systems so that I don't run the risk of screwing up something in in 24 v system. I'm going to be running some items related to a wvo system as well as some other 12 v accessories. I also going to use it to occasionally power a high amp 12 volt inverter.

 

[MrAugust]

a ha... i get ya, use a power reducer, in the jeep some on has done as stated above, and made a fuse typr reducer that brings the load to 12 v... its like 8 fuses starting high to low to winde down the load, its weired, but an army conversion in batt box... to run 12 volt flashers/ beacons......

 

[devilman96]

You can add an inverter but can only get so many amps but enough to run a radio plus a few odds and ends.

Pulling a 12V wire off of one battery is not a good idea, when you hit the ign switch you have 24V and your throwing your load off between the 2 batteries...

You can add a alternator and 3rd battery which is a must for lighting, pumps, fans, etc... This is what I did to my truck using a single wire alternator and 3 gel cell batteries which fit into the original box just fine.

 

[reblawyer]

Great Devilman, thanks for the image, did you run another pully there or just lengethen the compressor belt?

 

[abh3]

I hate to be insubordinate to General Devilman96 but the 12v off one battery idea has been working around her for probably a decade on various heavy equipment. I'll be the first to admit that a few floodlights aren't a big load... in fact, the largest single load we have run like this is a 12-14" electric radiator fan mounted in the top of an excavator cab for some ventilation here in the Deep Dank South, not much but ya gotta admit it's hard to argue with backwoods success... With proper wiring and overload protection the battery will be the limit, I figure the worst you could do is wear out that battery before the other... No guarantees though, keep the fire extinguisher handy!

Also, don't ham radio guys do alot of 24v to 12v? That might be a place to look for a proper power-supply without the complexity of an additional alternator. And it seems like Surplus Hydraulics used to have 24v DC to 120v AC inverters. I have a Vector 3000w inverter in my Dodge truck and love the convenience! It's wired with 1/0 welding wire per the book with a huge fuse for overload protection. Works great!

 

[Gatnom]

Much as I hate to, I've gotta get in this. abh3, your right in the fact that it does work, (I'm even guilty) but that unfortuanately does not make it the thing to do. What you are doing is creating a voltage imbalance in the charging system. What happens is that the voltage regulator sees the voltage drop in the system, but because you are actualy dropping the voltage in only one battery, (almost everyone uses the battery that is grounded directly), the battery that is above ground is overcharged, suffers from low water level and usually ends up being replace 2 or 3 to one to the grounded battery,(it just plain gets cooked). You can help to balance the load by running an above system in addition, but the independent 12v setup is still the best advice. Dave

 

[abh3]

Ok, that makes sense and I believe you but, as lazy as I am, I'd rather change a battery from time to time than add an alternator, regulator, brackets, extra battery, battery box, etc. for a whole stand alone 12v system...

You know, the REAL way to do this is like they do on boats, with a' battery equalizer' (or battery balancer, can't remember) that allows 12v to be drawn off BOTH 12v batteries in a series so they are at an equal state of discharge when charging begins! I know these things are out there, hit West Marine or search online, it may be just the thing if it will provide enough watts for Reblawyers accesories...

 

[devilman96]

Reb,

I should have elaborated on my belts, I have also installed AC on my truck so mounting options were nil to none for the 12V. If I were to add just a 12V alternator to my truck I would put it above the 24V where my AC compressor is located this will allow you to simply run longer belts to the set up.

Build a 1/4 bracket off of the 3 water pump studs with a rear bracket to stabilize it from vibration to one of the manifolds... It doesnt need to be adjustable as the stock alternator has the adjustment already. If you have a welder and some cutting ablity it should be a afternoon project... Only thing to watch for is clearance issues with your shroud, it will fit but you made have to nibble out a piece of it pending the size alt you want to run.

My current location is running a belt from the water pump pulley as you do not have clearance to get the compressor belt up to where the alternator now sits.

 

[houdel]

I'm far from a Duece expert but on heavy equipment we just run a wire, WITH OVERLOAD PROTECTION like an appropriatly sized breaker, off one 12v battery in the series positive post to a little fuseblock (I like the ones for boats, they're tougher),then through switches and on to the various devices. The ground is similarly arranged, with a little terminal block and then back to that battery.This way I have 12v driving and flood lights (cheap!) and a radio on a 24v machine. I see no reason this wouldn't work on the Duece though the radio would have to be a THUMPER to be heard over the engine racket!!!

I hate to disagree with abh3, but what he suggests is a VERY BAD IDEA! It will work for a while, but running a a constant 12v source from one of your batteries is going to screw up BOTH batteries. The current load needs to be equalized between both batteries. If you tap off 12V from the dogbone between the batteries, battery "A" is going to have a higher discharge rate than battery "B". The charging system will try to recharge at the average current draw from both batteries in series, so battery "A" will be undercharged and battery "B" will be overcharged, and eventually both batteries will be toast.

The only acceptable solutions (if you are drawing more than a very minimal load) are to either use a 24V-12V converter working off BOTH batteries, or install a separate 12V battery and alternator to meet your 12V needs.

Sorry if you disagree abh3, but drawing 12V off a single battery willl work for a while, but eventually damage both of your batteries unless you arrange your system such that 12V is drawn off BOTH batteries at approximately the same current rate!

 

[NEIOWA]

Roscommon project file - adding 12V aux.

http://www.roscommonequipmentcenter.com/news_notes/nn9.pdf

Or perhaps change over to a CUCV setup to supply 24V and 12V
http://www.roscommonequipmentcenter.com/news_notes/nn10.pdf

 

[abh3]

There really is another way... For up to 100 amps of 12v off batteries in series check out:

http://www.vanner.com/pdf/man-0001.pdf

As far as continuing to defend tapping 12v off one battery, either we don't pull enough load to do long term damage or we're just lucky! I replace more semi-tractor batteries than the equipment batteries subjected to the above abuse...

Like a deer-hunter said to me last year, "I'd much rather be lucky than good!"]

 

[bottleworks]

There really is another way... For up to 100 amps of 12v off batteries in series check out...

I want to get one of those units, but they are $$$. Txsg created a write up on installing one of those systems in an M35.


http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=7542

 

[OPCOM]

Ok, that makes sense and I believe you but, as lazy as I am, I'd rather change a battery from time to time than add an alternator, regulator, brackets, extra battery, battery box, etc. for a whole stand alone 12v system...

You know, the REAL way to do this is like they do on boats, with a' battery equalizer' (or battery balancer, can't remember) that allows 12v to be drawn off BOTH 12v batteries in a series so they are at an equal state of discharge when charging begins! I know these things are out there, hit West Marine or search online, it may be just the thing if it will provide enough watts for Reblawyers accesories...

Please note that these equalizers work all the time when connected to the batteries. In a vehicle that is not used daily, it is necessary to disconnect the equalizer when unused or in the end you will have a discharged upper battery and a well charged lower. After a month, the truck likely wion't even start. That's why I installed a contactor in my setup so the equalizer's 24V and 12V terminals are disconnected from the batteries when the power was off.

 

[WillWagner]

Well, My 2c, Most all transit busses have a 24VDC alternator with no 12VDC alt. There are 2 systems on most busses, 12 AND 24 volt. They pull 24VDC off of both batteries, and the 12 VDC off of 1 battery, usually 8D series batteries. The 12V operates the faire box, radios, starting system relays, and the "special " bus crap. The 24VDC runs the bus VECU and engine ECM and lights. Believe it or not, busses are technoblimps. I think that whatever 12VDC item you wanna run off of the 24VDC system on a deuce will work fine.

 

[Towman2277]

I'm not sure of the "right" way to do any of this, but heres my ! I ran a Positive wire to a switched fuse block, off of one battery (12V) to run various 12 volt lights, occasional radio, etc, and have not had the first problem with batteries yet. I believe the largest item I do run off the 12 volts would be my CD player w/ speakers. This is not to say that I Could not have a problem, but soo far ( 6 months of everyday driving) no problem has arrived!!

 

[MrAugust]

i beat u all... i have 5kva ov power 240volts..... in back of my deuce is a generator...... runds everything from house TV, Radion... Lights... sorted... plus a 5 K sound system for shows playing music.....