I asked the mechanic working on my grader to check that it has a working alternator.  His reply was "it doesn't have an alternator fitted".

That lead me to various posts in the forum here talking about "generators" on Cat machinery rather than alternators.  I also had a look through my photos of the machine and saw the image attached.  That I assume is a "generator", probably 12 volt based on the plate on the box it is connected to.  I assume that was used to power the graders lighting and perhaps charge the pony motor's starter battery?

However - my machine has had an electric starter fitted to it which is 24 volt.  I would like to take advantage of that, but the pair of 12 volt batteries will require 24 volt charging.  Does anyone here have any suggestions about the best way to go about this?  I expect that this is a standard issue with machines that have been converted to electric start and I assume that there are some known solutions.  I would greatly appreciate any advice that can be provided.

Regards,
Langdon

Hi, LangdonStevenson.
You will need to have your batteries connected in series, NOT in parallel - that is negative to ground, positive to negative and positive to the starter. You will also need a either a 24 volt generator or a 24 volt alternator to charge them, plus the relevant regulator - some alternators come with regulator built in.

Just my 0.02.

Solar panel

are you sure its a 24v starter. 12volt units did exist.

these old girls are originally 6v as it was only to run lights and maybe a cabin fan.

to simply keep the batteries charged for starting a small 24v solar panel can be used with a charge controller to keep em charged.mount it on top of cab and presto charge whenever its outdoors.

or you could get a 24v generator to mount in place of the original.(this is rare and hard to find.) there is a american company that does generator to alternator conversions ie they mount custom alternator windings in a generator body(expensive)

or do what others have done remove the brushes and fan from the existing generator mount a lovejoy coupling or similar to the protruding shaft and mount a alternator minus the pulley but keeping its fan inline with that.

or you can do what i did dismantle the generator fit new bearings and have a longer shaft made to take the drive gear and protrude further from the brush plate end so you can mount a taper-lock pulley this allows the correct driven speed to be obtained so the alternator is working properly.

i also made a custom bracket to swing the alternator from so i can tension the vee belt with a bit of maths i calculated the right ratio to get the minimum drive speed for it to excite and start charging just above idle. taper-locks allow easy ratio changes as the one taper bush fits multiple pulleys.

both methods require a suitable voltage single wire alternator with built in regulator so they are self exciting this makes wiring simple. the delco SI models are ideal and readily available.

here's a tip when wiring multiple batteries the leads joining batteries to each other must be the same length.
and the leads to the battery bank should be the same length too particularity if joining more than 2 together.
the ground and positive feeds must be at opposite ends of the battery bank so it acts as one large battery this means they'll have better service life as they charge more evenly. (like water electric current will follow the path of least resistance so shorter lead equals less resistance)

going down the conversion route means you'll have ample power and can have those mod cons like decent lights, a cabin fan or even get real flash a decent radio and speaker system or even a portable fridge to keep those beverages cold.

Hi, trainzkid88.
To the best of my knowledge, Cat did not make a 12 volt direct electric starting system for any of their diesels, They made 6 volt systems early on for lights and 12 volt systems later for lights and pony motor starters.

You can find 12 volt direct electric starting systems on some of their smaller units nowadays since Cat stopped making the engines for those units.

Just my 0.02.

If charging a 24v system with a 12V generator system, you have two pretty simple choices, one is to charge each battery separately with a charger, no need to disconnect them, or if using the 12v generator, you will need to set up a switch that will allow the generator to be connected to one at a time, after starting the grader, allow the generator to charge one battery for half the time you expect to run, then switch.
There are other options, but they get more complicated and expensive.

Cat did use 12V starters for the main engine on some of the early D2 J models.

Hi, Josh.
'Kwik kwestyun': If you had a disconnect switch between the two batteries of the 24 volt system and the output wire from the 12 volt generator connected to BOTH batteries, could you charge both at the same time safely simply by turning the disconnect switch to 'off'?

This kew-ree-yuss mind would like to know.

Why I ask is that I have a Redarc automatic disconnect switch between the main battery and the auxilliary battery on my pickup back home. When the 12 volt alternator is charging, it automatically charges both batteries at 12 volts each.

How-wevver, when the alternator stops charging, the Redarc switch automatically disconnects the two batteries so that using the auxilliary for lighitng and for the fridge in the camper on the back does not run down the main battery.

I am wondering if a similar system could be set up using the starter switch to power the auto disconnect switch to give 24 'jolts' for starting but automatically disconnect them straight after starting to allow the 12 'jolt' generator to charge both at the same time.

Just my 0.02.

My guess is you have 6V generator. Since it looks typical to what would of been original with the grader, black lettering on the tag 6v, red lettering was 12V. I don't see any red in the picture. But the black/red color was a Delco thing, and from picture I cannot say it is Delco.


But what kind of use do you plan, and what climate are you in? If you are running lights, or just using the batteries to start, the charging needs are very different. The simple cheap way is charge with a battery charger or solar charger. If you are plowing snow in the dark you need to put a working charging system on it.

 

Hi Deas,

Yes you can charge two batteries that way, but the batteries must be well matched condition wise, and properly maintained or one will be over or undercharged resulting in shorter battery life or other problems.
It is my opinion that batteries wired like that in seldom used equipment are better off being charged separately.