converting 2-6 volt batterys to 2-12 volts 4430

To get these tractors to start the Delco starter has got to go. They just will not crank the engine fast enough in cold weather. A Nippondenso 4 kw is much better, but a iskra 4 kw starter will spin it faster. The Iskra is cheaper also.

Disregarding all theory and fact about current delivery from two six in series or, two twelves parallel, from experience, two properly wired twelve volts will do the best job. The battery cables from the left battery positive to the starter solenoid, negative to the ground stud on the starter, (if you get an Iskra) or to the starter mounting bolt, for Nipondenso. From the right battery run the positive to the same stud on the solenoid, and the negative to the starter ground stud. The extra cables make the difference. I have seen the series six volt cables actually stiffen up and jump and down when trying to turn a cold engine, and a cold hydraulic pump. The Delco starter will not take this load.

If you don't get large amount of black smoke, for a few seconds, after it starts, the pump is not going into start delivery, and the pump needs repair. Also be sure the fuel is not draining back out of the pump.

Next, if say a 6 volt battery is rated to deliver x amount of Cold Cranking Amps (CCA), if you place two in series, the CCA STAYS THE SAME, but now the combination can deliver those same amount of amps at TWICE THE VOLTAGE, therefore, they can deliver twice as much instantaneous power (Volts x Amps). However, as noted above, just cuz there are now 2 batterys versus one single dont necessarily mean theres more stored energy, remember, it all depends on the individual battery ratings, types, sizes, quality and technology.

That all being said, lead acid batterys store energy via lead n acid, and the heavier rated batteries have more of both. Thats similar to why if the combination of two sixes has more lead n acid then the single 12 (given all else equal) then in that case more lead n acid means more stored energy. If you notice, the higher rated batterys are physically heavier AND USUALLY BIGGER, as they indeed contain more lead n acid.

If the batterys were identical (the 6 or 12) in manufacture n quality n technology and type, the physical combination which is bigger and heavier will PROBALBY store more energy. Thats why if the two sixes completely fills the battery box they will store more energy than a 12 volt unit which is only half the size. The 12 volt battery has 6 cells (2.1 volts each) while the 6 volt has but 3, but the 12 can be thought of as two sixes in a single case. You could, however, take a 6 volt case the same size as a 12 with only 3 cells but each more lead n acid and you can see why two of those suckers will store more energy than a 12 of half the size !!

A more accurate comparison may be made if one knows the amp/hour battery rating like they used to label them. (Remember two sizes in series delivers the same rated amps but at twice the voltage). The amp/hour rating has to do with how many amps the battery can supply for how long before the voltage drops to a certain level, therefore, as it concerns volts x amps (power) over time, thats how much energy it can store n deliver, similar to how many watt (V x A) hours of energy you buy from the electric utility.

Sooooo ooooo it may be true that two sixes in series can crank her better or longer than a single 12 or the opposite may be true. IT DEPENDS ON THE BATTERY RATINGS. About the only thing I would dare to make a general statement on is if the batterys were of identical make n type n quality n technology, then whichever combination that has the more lead n acid n plates (i.e. size n weight) stores the most energy.

Sorry I cant give you any easy simple answer youre lookin for, but whichever combination that stores the most energy can deliver the most to the starter motor is the bottom line. You asked about two twelves in parallell, in that case it can deliver TWICE THE AMPS as a single 12 and at the same voltage, but energy concerns Volts x Amps (power) over time, so you have to be able to compute total stored energy (function of lead n acid) to know the amswer.

Great question n discussion

Good Luck n God Bless Yall

John T

I can think of no reason that two 12v would give less cranking than two 6v??

Hook up the two 12v neg to neg and pos to pos. You still have 12v but you have doubled the amps available for starting.

Gerald J.

Two 800 CCA at 12 volt in parallel will give almost 1600 CCA just about the rating of a good 6 volt battery.

As Ol John T. says, (an electrical engineer, he does know) the difference between two 6 volt batteries in series or two 12 volt in parallel depends on how well each is made. A 12 volt battery is NOTHING MORE than two 6 volt batteries in series. Actually a 6 volt battery is 3 2 volt cells in series and a 12 volt battery is 6 2 volt cells in series. The voltage comes from the number of cells, and the current capacity comes from the effective area of the lead sponge in the plates. More plates and thicker plates means greater capacity. Lots of lead makes a high capacity battery, light weight makes a low capacity battery.

There's not enough difference between two 6 volt batteries in series and two 12 volt batteries in parallel if both sets of batteries FILL their battery boxes and are the best quality batteries to detect by cranking speed and for sure not enough to justify the cost of the different cables. Also a bad cell in one 12 volt battery will kill the other battery, while a bad cell in one of the two 6 volt batteries won't kill the other battery.

Another consideration, IF the battery cases are truly filled with plates is that in a 6 volt battery case there are only two dividers taking up space while there are 5 in a 12 volt case to there might be room for a bit more plate area in the 6 volt batteries for a bit greater cranking capacity.

Neither arrangement allows one to ignore keeping the battery posts and other battery circuit connections clean and from using the heaviest available battery cables.

Gerald J.