756 Correct 6 volt batteries

[Michigan No Till]

Will you guys give me part or group #s..

Deka 402E ??

Total height 9 1/8"

Everyone at the parts store wants to sell me the taller version, too tall posts will hit the fuel tank!!

[brahamfireman]

I must have some sort of freak 756 because I read about this problem all the time but never experienced it with my 756.

Was there different battery trays?

On edit, I see why I don't have this problem,  I run 12V 3ET batteries in everything the posts are together in the middle.  I'm a little slow still this am.....

[Michigan No Till]

Not sure it's a mystery.

Bought the tractor and it had the tall 6V, rubber strap holding them in place. 

Posts were so close to the fuel tank. 

And the stock covers and hold downs would not fit.

Replaced them 6 years ago with the correct batteries and put the stock covers back on, factory look and proper. 

Now they need replaced again and the numbers are faded, can't read the important part and group ####.

[Farmall1066]

Yes the Deka 402 E is the battery you want, just a hair over 8.75 inches tall.  The 3EH if I remember is 10.25 inches tall?! Guess I could look.  

[FarmerFixEmUp]

Group 2E, some places have them yet but they're expensivve. 

https://www.napaonline.com/en/p/BAT7205

Lots cheaper to go with 2 group 3ee 12 volt batteries. Wlll need 2 grounds and 2 positive cables and will fit under the covers.

 

https://www.napaonline.com/en/p/BAT7250

[Michigan No Till]

Thanks for the help guys

Not ready to switch over to 12V yet 

I'm going to clean posts and clamps

Top off with distilled water

And charge over night when I'm done planting today

Was told to put charger on the posts one battery at a time

On 12V/10 Amp setting for 20 minutes to knock off sulfated plates 

Anyone tried doing this?

[brahamfireman]

38 minutes ago, Michigan No Till said:

Thanks for the help guys

Not ready to switch over to 12V yet 

I'm going to clean posts and clamps

Top off with distilled water

And charge over night when I'm done planting today

Was told to put charger on the posts one battery at a time

On 12V/10 Amp setting for 20 minutes to knock off sulfated plates 

Anyone tried doing this?

Putting 12 volts to a 6 volt battery will be very bad. 

Back when I liked fighting the dual 6 setup we always charged 12V right at the starter stud.

[HydroTek]

... or just put a single group 31 at the RH battery box

and use the LH battery box for something useful like a grease gun storage 

[Sparky]

2 hours ago, Michigan No Till said:

Thanks for the help guys

Not ready to switch over to 12V yet 

I'm going to clean posts and clamps

Top off with distilled water

And charge over night when I'm done planting today

Was told to put charger on the posts one battery at a time

On 12V/10 Amp setting for 20 minutes to knock off sulfated plates 

Anyone tried doing this?

You aren't switching over to 12 volt, you're just switching to two 12 volt batteries.
Nobody will know, nobody will care. 
Much easier to charge the batteries if you ever need to. 

Or just put one Group 31 in. Cheaper and starts just as good if not better.

Travis

[Jeff-C-IL]

Apologies if you already know all this, but some don't so:

Your (2) 6V batteries are hooked in series to give the equivalent of (1) 12V battery.   All your other stuff on the tractor is 12V - lights/starter/wiring - unlike older models which really were 6V.

• If you really want to keep your tractor completely original- then yes, you will need the 402E's
  • Advantage - original for the show tractor
  • Disadvantages - cost, any bad connection in the series means no power at all.

But there are better cheaper options available today.

• (2) 3ee 12V batteries.   Just replace & reconnect the cables so that you have the batteries in parallel.
  • no need to rewire anything except battery cables - its still 12V
  • Cheaper, looks original, 1 bad connection means you still have 1 battery connected.
  • Starts as well or better
• 1 semi battery -  
  • Cheapest
  • Does NOT look original - requires a batter box redesign - may get in way of loader frame, etc.
  • Bolt post connections means less "post corrosion" problems (IDK why all batteries do not use this)
  • More CCA to start tractor

Any of these solutions will work to start your tractor.   Its your tractor!   Even the IRS can't tell you which battery to use - although the EPA may try!

There have been, over the years, all kinds of "battery revitalize" solutions, ranging from total quack to sophisticated "chemistry"-- some may work, mostly not.   I have never found any that do.   Others may disagree.   My thoughts:

• If something really worked - everybody would be doing it and we'd all save on batteries
• Some are too dangerous - charging a 6V battery on 12V risks the battery exploding.  

[Jacka]

9 hours ago, FarmerFixEmUp said:

Group 2E, some places have them yet but they're expensivve. 

https://www.napaonline.com/en/p/BAT7205

Lots cheaper to go with 2 group 3ee 12 volt batteries. Wlll need 2 grounds and 2 positive cables and will fit under the covers.

 

https://www.napaonline.com/en/p/BAT7250

I like that idea. I will have to check that out.2 6 volt never really floated my boat in those tractors.I kept all covers and hardware to my half a dozen tractors that take them but switched them to group 31s.Not the prettiest instalations but works.

[brahamfireman]

On 5/6/2026 at 4:43 PM, Jacka said:

I like that idea. I will have to check that out.2 6 volt never really floated my boat in those tractors.I kept all covers and hardware to my half a dozen tractors that take them but switched them to group 31s.Not the prettiest instalations but works.

We own 3 06/56 diesels and only 1 is still set up with dual 6V batteries  and once they die it'll get dual 12's. Looks the same, cheaper, and less a amps through one crappy cable.

[stronger800]

I like battery threads

I wouldn’t put 12v on a charger to a 6v battery.  I’d clean the Cables and charge them together at 10a for an hour or two,  and then on 2-5a over night.  If that doesn’t work, they were shot.

We typically get 10-14 years out of the 6v’s, and that’s never charging them.  Modern automotive batteries seem to die before 5 years these days.  Friend just put a set in his ‘22 duramax, and I put one in a ‘23 Toyota.  Toyota battery cost more than the diesel, but there were two of those to buy.  Years ago it seems they’d last much longer 

[Sparky]

It's not terribly difficult to fabricate an aesthetically pleasing battery tray and cover for a group 31...

I'm surprised someone in here hasn't done it and marketed one yet.

Most of us in here have seen the chrome battery covers for the original setup with the IH on the side. I'd think that would be a great idea.
 

Travis

[Michigan No Till]

Thanks everyone think I will replace with 12V in parallel. 

6V are too expensive and hard to source. 

See most have discontinued. 

[stronger800]

Guys have talked about bending the outer “upward flange” down flat on the original battery trays, to slide the battery’s out an inch, making 3EH’s ($150 ea) clear the fuel tank too. Then weld another strip of steel back on for the flange. Or cut it off and space it out.  Some guys have put nuts behind the bracket/tray mounting bolts to space them out too.  Put covers back on. Would be a free suggestion that looked more oem than a grp 31 or two.  

[acem]

The 12V application may work, IDK.  I'm pretty sure the method was 16 volts on a 12V for some time to desulphate the plates.  I think the term may be equalize charge but I'm not sure.

You don't need two group 31s on a 706.  One is more than enough.  I often run just one group 24 but I live in the sunny south.

[HydroTek]

Yeah, one group 31 is plenty

use those batteries because they are less expensive -- popular battery in the trucking world
go see your local big truck store to get the battery -- the price difference is worth it

[Matt Kirsch]

There's a picture floating around on this forum of Dad's 856 with a group 31 in it. He even used the stock battery cover to hold it down. If someone 3D printed a block of black plastic to fill in the gap at the back of the battery tray you would not be able to tell the difference from a distance.

[Jacka]

1 hour ago, Matt Kirsch said:

There's a picture floating around on this forum of Dad's 856 with a group 31 in it. He even used the stock battery cover to hold it down. If someone 3D printed a block of black plastic to fill in the gap at the back of the battery tray you would not be able to tell the difference from a distance.

I see you extended the battery tray.I was wondering how you got it to sit there. Good idea.

[stronger800]

Same as I suggested just above, to fit 3EHs  if a guy wanted to. 

[Matt Kirsch]

7 hours ago, Jacka said:

I see you extended the battery tray.I was wondering how you got it to sit there. Good idea.

The extension just sits on top of the original tray, no permanent changes.

[acem]

Those wide batteries make it hard to watch the row when cultivating.