Cub battery

Tue Nov 12, 2013 7:57 pm

Our 1950 Cub has a 6 volt system. My father bought a 9 volt battery (4 cells instead the 3 cell 6 volt) a few years ago and it just turns the starter a little faster.
He has since passed and was wondering, if the battery needs charging would the 6 volt setting be used on a 6/12 volt charger as I haven't found one that has a 9 volt selector. Is anyone familiar with the 9 volt battery?

Re: Cub battery

Tue Nov 12, 2013 7:59 pm

Actually an 8 volt battery, I suspect. Lots of people use them on Cubs to get a little extra starting speed. I never thought to ask anyone how they charged it, but I've never seen a charger with an 8 volt setting.

Re: Cub battery

Tue Nov 12, 2013 8:15 pm

Use the 6 volt battery charger. Most 6 volt battery chargers, charge at around 7.5 volts. This will not fully charge the battery but should be sufficient to start the tractor.

Edit:
http://www.batterystuff.com/battery-chargers/8-volt/

Not sure I would spend the money for an 8 volt battery charger, rather repair the 6 volt electrical system, or better yet, convert to 12 volt.

Re: Cub battery

Wed Nov 13, 2013 2:12 am

I have an 8 volt and I charge it on 6 volt. no problems so far.

Re: Cub battery

Wed Nov 13, 2013 8:25 am

My guess is that Cubs with the cutout only, not a regulator, would eventually fully charge the 8 volt battery with the generator. The 6 volt charger will leave the battery partially discharged and the plates will sulphate. My guess is that an 8 volt battery charged only with a 6 volt charger will have a rather short service life.
A Cub with a regulator probably would not fully charge the 8 volt battery-- but that is just a guess.

Added later: My comments are tempered by the fact that I have never owned nor used an 8 volt battery-- no personal experience with them. And it would take a lot of persuasion to get me to buy one.
Last edited by Bus Driver on Wed Nov 13, 2013 3:28 pm, edited 1 time in total.

Re: Cub battery

Wed Nov 13, 2013 9:14 am

The old chargers with no electronic controls seem to be able to overcharge a battery if it is left on long enough. So I guess that an old school 6-volt charger will eventually bring an 8-volt battery to a full or very nearly full charge. I have no idea how long it would take.

I agree with what was already stated on the tractor charging system. A cut-out system should fully charge the 8-volt battery. It will probably not do it as quickly as it would a 6-volt system as higher engine speed will be required to produce the higher voltage. A regulator system will not charge it unless the regutor is readjusted for higher voltage. Attempting to readjust a regulator is probably about as likely to destroy the regulator as not. With good regulators as expensive and harder to find than good batteries, I think trying to readjust a regulator for an 8-volt battery is a false economy.

Re: Cub battery

Wed Nov 13, 2013 11:16 am

I will second what Bus Driver and Jim Becker have stated. A voltage regulator stops charging when it reaches it's preset voltage. A cutout keeps charging as long as the generator puts out current, and you control the charge rate with the Hi - Lo setting on the light switch. Much of the time higher voltage batteries are put in because the cables and connections need maintained. My statement is based on personal experience, as well as having been an electronics technician for 45 years doing commercial 2way radio and mobile phone work, and for 25 years working as a switching technician for the local phone company where everything is run by batteries, and you learn a lot about batteries and proper connections. Working in a phone office you get real unpopular if you have anywhere from 40 or 50 customers up to a few thousand out of service due to a loose battery power connection, or an improperly maintained battery.

Re: Cub battery

Wed Nov 13, 2013 11:55 am

I use an 8 volt battery and charge it with the 6 volt setting on the charger. I'm a firm believer in charging a battery with the cables disconnected and do not charge overnight. I have used this same battery three years now. My charging system does work with the light switch which is a big help.

Re: Cub battery

Wed Nov 13, 2013 12:08 pm

John *.?-!.* cub owner wrote:...... for 45 years ....... for 25 years ............
Let's see 45 plus 25 plus you were what, 18 when you started, that makes you about 88 I figure :D :lol:

JRICK wrote:........ I'm a firm believer in charging a battery with the cables disconnected and do not charge overnight. ..............
The overnight part I'm pretty sure I can figure out the reasons for. The disconnected part leaves me a little more unclear. I can think of a couple possible reason's but am interested in why you are a firm believer in it.

Re: Cub battery

Wed Nov 13, 2013 3:16 pm

Scrivet wrote:
John *.?-!.* cub owner wrote:...... for 45 years ....... for 25 years ............
Let's see 45 plus 25 plus you were what, 18 when you started, that makes you about 88 I figure :D :lol:
the 25 years with phone company was part of the 45 year total. I know that is tough for a hillbilly farm kid to understand, but that is the way it is er was. :lol:

In case anybody wonders, Scrivet and his brother (Rabbit Holler Flash) are both my friends and neighbors, so we harass each other a lot.

Re: Cub battery

Wed Nov 13, 2013 4:41 pm

how about those $20 6/12v automatic chargers from Wally world? If they adjust between 6 and 12 volts, why not 8v?

Re: Cub battery

Wed Nov 13, 2013 8:34 pm

I think that the 6/12 chargers offer no advantage for the 8 volt batteries. The transformer, in some chargers, has a center-tappped secondary. 6 volts uses one half of the winding by making one of the connections to the centertap. 12 volts uses the full winding. Nothing there to supply other voltages.
I did modify a bad charger for other purposes that might be good for 8 volt charging. Gutted the charger leaving the ammeter and the battery leads with clips. Added a 500 watt wirewound rheostat (adjustable resistor), probably 50 ohms or so-- don't remember exactly. Added posts to accept the battery clips from an unmodified charger. So set the good charger on 12 volts and adjust the rheostat for the desired charging amperage- which cannot be greater than that of the good charger. The rheostat is in series with one of the battery leads.
The downside is that the rheostat wastes as heat any power not sent on after the rheostat. But since the rheostat would be dropping about 4 volts if charging an 8 volt battery, the heat is not great. It would be 40 watts at 10 amperes in this instance.
I use mine for low rate charging of lawn mower batteries if ahigh amperage charger is all that is at hand.
But I am not encouraging the use of an 8 volt battery.

Re: Cub battery

Wed Nov 13, 2013 10:20 pm

vttrailboss wrote:how about those $20 6/12v automatic chargers from Wally world? If they adjust between 6 and 12 volts, why not 8v?
I do not think they would work. I have and do use them, and one of the things I have learned is the smart chargers are not very smart. They check the voltage, then charge the battery to the next step, either 6 or 12 volts. If your 12 volt battery is discharged to below 6 volts they charge to 6 volts and stop. Will not go further unless you use an old style charger to get it up to around 7 volts, then they will go ahead and charge to 12 volts, but do not stop at 8.

Re: Cub battery

Thu Nov 14, 2013 12:06 pm

Scrivet, In trying to answer your question as to why I'm a firm believer in disconnecting the battery cables.It is mostly a habit because of the electronics in the newer vehicles...My way of thinking on a cub,and I'm not an expert,is if you have a fully charged battery and as soon as you connect the battery it starts to discharge.I would start troubleshooting the reason for the discharge without second guessing the battery condition.Yes, I would have used a load tester on the battery while I had it disconnected.

Re: Cub battery

Thu Nov 14, 2013 12:43 pm

JRICK wrote:My way of thinking on a cub, if you have a fully charged battery and as soon as you connect the battery it starts to discharge. I would start troubleshooting the reason for the discharge without second guessing the battery condition.
Batteries have a self discharge rate, one web site says 3% per month, battery cables connected or not. With newer vehicles the discharge rate will be higher than the self discharge rate because of the on board electronics.

However, for a Cub, the pace at which a battery self discharges will be the same, cables connected or not. If the tractor sits for a prolonged period of time without being started and the battery recharged, you could find a depleted battery.