24 volt system battery charging

How do I hook up a 24v charger to a 2 x 12v battery, 24v charging system?

Is either positive and negative ok, on alternative batteries, or must they be charged in one particular way?

The batteries must be connected in series so that in effect the 2 12v batteries have become 1 24v battery. Hook the leads of the charger to the terminals of the 24v battery. Done.

OTOH why would you be charging with a 24v charger? Does the machine in question operate on 12 or 24 volts?

yes.. positive of one batter to the negative of the other.. then the positive lead of the charge to the free pos and the negative lead to the free neg

Andy, the machine in question is a 1966 MCI bus with a Detroit diesel, it is 24 volt, but utilizes two 12v batteries wired in sequence. There is no 24 volt battery, hence the question.

There are two options for connection, positive on one to negative on the other, just wondering if it matters which way they are hooked up. Both batteries have a positive and a negative obviously.

yes. Most larger trucks use 2 twelve volt batteries to make 24 volts. Two batteries wired together.. positive to negative will produce 24 volts.

The other alternative is to unhook the batteries from each other and charge them individually

Thing you have to be careful of. Make sure they are really wired in series. I have seen some smaller box trucks with 2 12 volt batteries... but the truck still ran on 12 volts.. it was only using two batteries for starting amperage

it is 24v

I usually identify where the positive and negative are leaving the battery box and hook to+ & - at that point.

That's the info I was looking for, thank you.

I haven't blown a battery yet, YMMV . Negative ground? (most likely) . 24 volt charger?

Yes, getting one over the next week or so, charger and maintainer.

Like this

http://www.ebay.com/itm/330661055679?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_1801wt_1037

Looks like a good maintainer unit. got a block heater? Will it be started over the winter? We have used a heated dipstick or a magnetic heater on the oilpan in cold weather.

No block heater, it would only be started to get the hell out of the snow, probably not going anywhere until the Mitty as of right now though. The magnetic heater sounds neat though.

I have a few projects to do on it yet, like a hitch that has to clear the engine cradle, steering maintenance (maybe a steering box)

May I suggest some anti gel in the fuel Before the weather gets stupid crazy cold?

Hmmm, is Stabil OK in diesel?

Sorry I am a total newb when it comes to diesels

Cetane boost, best I remember it's a diesel fuel additive. Sta Bil I have no knowledge of in diesel fuel. I could look at a bottle tomorrow.

Anti-gel is separate from Sta-bil, although there is a special diesel formulation Sta-bil that's about $20/bottle. You can find anti-gel at any FLAPS and probably any nearby truck stops as well.

Go to your local Wally World and get Kleen Diesel fuel conditioner.

I will get something tomorrow either way

There are a couple ways to charge. Like has been said, you can disconnect the jumper between the batteries and charge each on individually with a 12v charger. You can get a 24v charger and hook them up positive to the positive post (the one that goes out to the starter) and negative to the negative (the one that goes out to ground).

You can also get a marine 12v charger that charges two banks and hook each negative to each negative, and each positive to each positive. They have discreet outputs (not linked together) so that you aren't shorting anything and it will charge each battery separately treating them as two individual 12v batteries.

kerosine can also work in a pinch to keep diesel from gelling.

I would look around for a block heater.. I bet it already has one

Good idea it did serve in Illinois as a CCNO vehicle

thanks Curtis that might be a good option, I didnt know about those chargers

For wet cell battery maintenance I love Battery Tender brand by Deltran. I have 3 of the 12V Battery Tender Plus models at home - 2 are in constant use. One for a car that is mostly stored but gets driven a a moments notice, one for the tractor that only gets used for snow removal and occasional maintenance around the place and a third that moves back and forth to keep the generator and lawn mower batteries charged.

They do sell 2 and 4 bank models but I found I could buy 2 single bank charges for less than the price of one 2 bank model and since the car, tractor, and the generator and lawnmower are stored over 100' apart in three separate buildings a multibank would not have worked or me anyway.