The difference in Batteries

[highyields]

I have a JD 4040 that is equipped with two 6 volt batteries.   I need to buy batteries so I want to switch them to 12 volt.   If I place two  car/truck batterys ( I was going to use two 850cca ) vs. using the bigger  tractor size batteries  What am I losing if I switch to a smaller case battery with the same number on cold cracking amps?     

[Shaggy98]

Several years ago, we had a couple IH 856's and a Case 930 that we did this very same thing.  The hardest part was getting a battery that was able to fit in the long narrow box.  As far as performance, one 12volt will work just fine as long as you have the proper CCA, at least we had no issues.  If I remember correctly, I think we went ahead and made new HD cables as well.  I can't recall a single issue we had with the change over, and we used each tractor for several years to follow.

[Pat in CMO]

Generally a larger case size battery with the same CCA rating will have a higher reserve rating. This can make a big difference if you ever have to crank very long to start the tractor. My preference is to use the largest case size that will fit.  Patrick

[Nebrfarmr]

The only problems I have heard about with that sort of changeover, is not having matched batteries. If one is bigger, or even newer than the other, you risk undercharging one, or overcharging of the other. That, and being sure the cables are good and the connections are clean.

[siloguy]

If you are going to put in two 12V batteries, I guess I don't see any benefit, unless they are cheaper. If the room is there to replace the two 6V with one big 12V, I have done that and that is an improvement because you just eliminated half of the potential bad connections. And with two batteries, it seems one always dies first and drags the other one down. One good tractor battery like a 4D probably is all you need unless the JD starts harder than most. I have them starting engines over 200 hp and they are rated at only 1000 CCA and they last many years.  The big battery will give you the cold cranking for longer and things like glow plugs don't bring them down before you start.

[siloguy]

To answer your question, you probably are not losing anything. The thick case tractor batteries are tougher and I have read that they are stronger construction inside as well. But if your tractor lives a peaceful life that may not matter. You also may have to fab some hold downs.  If you want to gain something and space allows, go to one big battery. and use good connectors. The copper ones that solder on are great.

[onebigbyrd]

just remember if u hook 2 twelves up to put them in paralel not series like the 6v were

[highyields]

All good thoughts,  Thanks.