8 volt battery

Went to TSC last night (yea I know, but that is all that is close). Was looking for a 6V battery, but they only had an 8V so I bought one. Will this do any damage to my JD M? Will there be any noticeable difference? Do I need to make any changes to the charging system? Thanks

The systems i have seen they just get the polarity the same and use it. I did some work on a C that had one for years it still had the cutout on and the batt still read good on the hy. Sure makes the starter turn good his lites worked also. I know of a couple more that run 8v batts.

Unlike 12V batteries when used with 6V starters on some engines, the 8V battery should not damage anything but the charging system will not keep it charged unless you know the largely lost art of adjusting voltage regulators.

Dean

My owners manual for my Farmall H said the volt. regulator cant be ajusted, but the manual for my Cub Cadet Original said that one can be adjusted. Anyone know how to adjust volt reg. on something like my H? Could it be turned up to charge the batt to 8 volts instead of 6 volts?
Ryan in Northern michigan

Ryan:

Any magnetic voltage regulator can be adjusted if the cover is removeable but only by one who knows this largely lost art.

This is not something that I will attempt to tutor in a chat room.

Dean

30 years ago, we used to install a lot of 8 volt batteries into 6 volt tractors. It will only work if you turn the voltage regulator up. Normal setting is a max of 7.1 volts, and you have to get up to at least 9 volts. Adjusting is easy, you just have to increase spring tenstion. With some, you bend the sring arm, and with others, there is a simple screw adjustment. If the cover is riveted on, you just drill the rivets out.

First of all a small M should start and work fine at 6 volts if it has a good heavy battery and 0 or 00 Gauge battery n starter n ground cables.

Next, it wont do much harm other then the points will burn up a bit sooner,,,,,,,the lights will be plenty bright but likewise may burn up a bit sooner,,,,,,,the coil will run slightly warmer (unless you add some external ballast)

CHARGING ISSUES: The M originally DID NOT USE A VOLTAGE REGULATOR.....but a 2 wire (Bat Gen) Cutout Relay soooooooooo theres no Voltage Regulator to adjust... But yours may have been modified????????????????

The M originally regulated the rate of charge (via the light switch) by adjusting the gennys Field current by adding a small resistance to the Field windings when in Low charge but dead grounded the Field when in High charge or lights were on.

A genny dont necessarily know what its voltage is supposed to be, its increased if you turn it faster or increase its field current. You can charge an 8 volt battery with your existing genny but it may not charge at a real high rate.

I would make sure to install it at the same polarity which was originaly POSITIVE GROUND and for safety Id polarize the genny then see what happens???????? If she charges positive at higher RPM Id just run it a while n see how she does WITH NO CUTOUT RELAY OR GENNY CHANGES. However if she doesnt charge satisfactorily it may be possible to make some minor modifications such as but not limited to adjusting the third brush for a higher charge IFFFFFFFFFFFFFF it has a 3 brush genny.

Hook it up at the correct polarity (original Positive ground) Polarize the genny,,,,,,,,,see what happens is what I would do and then if necessary look into any third brush adjustemtns (if its a 3 brush genny) or other tweaks IFFFFFFFFFFF necessary.

John T

I disgree, strongly. A one volt jump in actual cranking voltage can make a huge difference in any system, 6, 12, or 24 volt. We had many 6 volt MCs, 40s, 420s, etc. Customer's machines that sat in the woods at temps down to 35 below F. They sometimes had trouble starting. With the best cables, controls, and standard battery, cranking voltage will still drop to 4 volts when it's well below zero, and cranking will be extemely slow. Using an 8 volt battery in that type of situation can make a big difference. And yes, using an 8 volt instead of a 6 is "robbing Peter to pay Paul." You gain cranking speed but lose some reserve capacity. Installing a huge 6 volt battery can also get the crank-voltage up.

As to having a regulator or not? Condsidering the age of an M, and the guy mentioning his regulator, I have no idea what he has, or if it's never ever been altered. We put Delco two-unit regulators on many MCs, # 1118308, to be used with the Delco shunt-wound 1101859 generators. Two unit regulator, with one being the voltage regulator. Increase the spring tension and the voltage setting climbs from the OEM 7 volts ,up to around 8.5 - 9 volts. Just enough to keep that 8 volt battery charged. With three-brush generators, it was sometimes more a struggle to make work.

So you are saying that your system didnt keep the battery charged when you went to the 8v batt.

Check an auto parts house they should be able to get you an 8 volt regulator that will work. any good Generator shop should be able to adjust your old one for you should cost much if anything.
Walt

Hey, JDeMaris, do you have an email that I can reach you? I can't PM here....thanks

sorry for the hijacked thread, everyone....

I still believe that the magnetic field comes from the voltage not the amps. If you have the gauges hooked up to a slow cranking starter, it shows as the voltage drops it cranks slower even though the amps goes up.

I'm not saying that at all.

I have never felt a need to use an 8V battery.

That said, I know enough about generators and voltage regulators to know that 6V magnetic voltage regulators will need to be adjusted in order properly charge an 8V battery

Dean

i cant say for sure on the jd's but never had a problem with 8 volts in my ford 2000 other than they werent much better than a 6 volt...finally changed it out to 12 volt alternator when my dad's back was turned and aint had a bit of trouble since,and thats 30 years later.

9.2V summer and 9.5V winter to charge an 8V battery.
Kinda leaves them machine in a "no man's land" being neither 6 or 12V.
All too often an 8V battery is used as a band-aid fix to compensate for electrical problems.

Thanks for the help. I will give your suggestions a shot

Power = volts X amps. Loose the volts and power goes down even when the current stays up.
Current is what makes ampere/turns which is how many gause of magnetic force.
If the magnetic force dropped, the torque would drop. The motor would quit cranking. Torque is proportional to current. Torque to crank the engine varies little if 20 or 100rpm.
It's current for cranking torque X volts to get rpm.
With electric motors, keeping the voltage up is everything. Just going to an extra large 6V battery and cables which keeps 5.5V cranking voltage instead of 4.5V of a weenie battery and cables. Makes the difference of having enough voltage for the plugs to fire.
It also allows the starter motor to make 1.5 times more power.
That's were the 8V battery usually figures as a farmer fix for small dirty cables and an undersized 6V battery. Even after loosing 2.5V the electrical system sees about 5.5volts as a sound 6V system would see.
The trade off in shortened lamp,coil and point life isn't worth it. Then again most old hack job tractors had the lights knocked off in collisions before the 8V battery was installed.