charging 2 batteries..correct hook up

[Randy G]

What is the correct way to hook up a battery charger on a 2 battery 12 volt system. The way I"ve done it is to hook the positive red clamp to the 1st batteries post and the black ground to the tractors frame. Is this correct? Does this charge both batteries? This is on a 2940. Thanks!!

 

[[email protected]]

Ground to the frame or one of the neg posts, pos on one of the pos posts. Correct.

 

[Scott 730]

Does the tractor have 2 12 volt batteries in parallel, or 2 6 volt batteries in series???

 

[Randy G]

It has 2- 12 volt batteries

 

[William Draper]

It takes all kinds of people to make the world go around but I have had better luck disconnecting the batteries and charging them one at a time. Just make sure your charger is set to the correct voltage for the battery being charged.
Just passing on my experience, do whatever works best for you.
Regards,
Bill.

 

[Loren NC]

The assumptions below mostly assume the batteries are hooked up in parallel. They PROBABLY are. If they are, the advice to put the charger on one positive terminal and on the frame is good advice. If by any chance they are hooked up in series to give you 24 volts for starting, you have a whole different situation. First of all it would take a heavier charger to do anything without disconnecting them and doing them one at a time as was suggested. Secondly, if you hooked the charger to the middle positive terminal, you would charge the last battery in the series but not the first one. If you are not sure what you are doing, the best advice you have gotten so far is to unhook them and do them one at a time.

 

[thurlow]

The gentleman said it was two 12V batteries on a 12V system. If it had been 24V, WHY WOULD HE HAVE TO DISCONNECT THEM TO CHARGE THEM......with a 12V charger?

 

[Randy G]

The way they are wired is....the positive red cable from one battery goes to the positive post on the other battery. It then goes to the starter I think. Both neg posts are grounded in each individual battery box.

 

[Bob]

"I have had better luck disconnecting the batteries and charging them one at a time."

Better luck, eh?

You REALLY should expound a bit more on that theory to bring the rest of us "up to speed"!

 

[Loren NC]

So it is hooked up in parallel, meaning you only get 12 volts out of it but a lot more cranking power. With it hooked like that, you can put the positive cable from the charger to either of the positive terminals and the negative cable from the charger to an ground point on the tractor frame.

By the way, you probably are not aware of a danger that exists when charging or discharging any battery. The process creates gases inside the battery. As some of that leaks out and you remove or check a cable connection, KABOOM! Frankly, the older batteries that had removable cell caps were safer because you could loosen the cap and let the gases escape during the charging process. It is because of these gases that it is ALWAYS recommended that you connect the charger negative cable to some spot other than the negative terminal on the battery. The spark you get when you connect it and the spark you get when you later remove it will not explode your battery. Be safe!

 

[Loren NC]

The gentleman clearly had no idea what he was dealing with. So you see harm in explaining the possibilities to him?

 

[buickanddeere]

Wm that would only be a benefit if one battery was ruined and the other still serviceable. Or if you inadvertently cleaned and tightened the battery connections.
I have came across lots of systems with 12V batteries in parallel. One battery was doing all the work and the other was just sitting there floating due to high resistance connections.
b.t.w. the chassis return cable on that tractor or any other for that matter. It bolts to some sheet metal which is not good electrical conductor.
Run a new heavy gauge chassis return cable direct from the battery to a starter mounting bolt.The engine will crank over as if a larger set of batteries were installed.

 

[DONMYEIL]

Yes that will work. Make sure the terminals are clean and the black clamp has a good connection. The biggest problem with battery charging is trying to use a lawn mower battery charger to charge up these big batterys. If they are completely discharged they need 3-4 hours of charge time at 20 amps or more. My 2 cents.

 

[Pete in MD]

The safest way is to make the battery connections as you describe THEN plug in the charger. And, unplug the charger first when you're done.