Charging a six volt battery

Simple question that is driving me crazy, short trip
I have a six volt battery for my 720 John Deere.
I am having challenges with the generator so relying on an electronic
plug in charger. The battery will not accept a charge. Brought back
the battery and got a new one. Put the charger on the new battery
again would not accept a charge or show the battery was charged.
Any thoughts on what might be the issue?

Charger problem?

I have an electronic charger that will not charge a battery if the voltage is too low. Hook the battery to an old school 20A transformer charge for a couple hours, then the electronic one will do the rest.

Check with a meter to see what the battery voltage actually is. Is it completely dead?

You should not have to charge a new battery, the last couple I bought were fully charged right off the shelf. You need a meter to check the voltage, but I suspect your charger is defective. Did you try starting the tractor?

(quoted from post at 18:29:59 05/11/23) Simple question that is driving me crazy, short trip
I have a six volt battery for my 720 John Deere.
I am having challenges with the generator so relying on an electronic
plug in charger. The battery will not accept a charge. Brought back
the battery and got a new one. Put the charger on the new battery
again would not accept a charge or show the battery was charged.
Any thoughts on what might be the issue?

Click to expand...

ope this isn't a stupid question, but is this a charger that is intended for 6v batteries?

What criteria are you relying on to say It will not accept a charge? Since it's a 720 is it a diesel or gas? The diesel with pony will have a 6 volt battery. A diesel with electric start will be 24 volt so your problem battery may be one of 4 or if it's a gas 720 it could be one of 2 six volt batteries.

all depends on what charger you have there. some of these new chargers are called smart chargers, but i like my good old fashioned stupid charger. BUT BUT, get your self one of them 50.00 load testers and that will answer your question quickly. i would never be without one.

Ron it is a pony start diesel according to a previous post, see link. To the original poster apparently you have the tractor running but only want to charge the battery with a charger until you decide to fix the tractors generator. Give us the brand and model of charger you are using. I agree with others get a volt meter, if it reads 6.4 volts it is fully charged. Does the battery crank the starter? To start that little pony motor does not take much if it cranks up fairly easily. It may not even drop the voltage enough in the 6 volt battery to make the charger initiate charge.
To others do you know how the circuits of the smart charger determine that the charger connected to a 6 volt battery and not a 12 volt battery with a low charge?
Previous post

have you tried the battery to see if it will start the pony? id bet it dont need a charge

First, understand there are two types of battery chargers - the trickle and the float. Take your VOM, digital or analog, either will work for this test, and set to VDC. Measure the battery voltage static. A good, fully charged 6V battery should show 6.4 VDC. Your basic garage-type trickle charger is not going to do squat if the battery is weak and won't hold a charge which usually means it is dead. A trickle charger, if not designed with an automatic shutoff feature, and left unattended, will overcharge the battery and boil out the water and electrolyte rendering it junk at that point. You just can't add more electrolyte, it doesn't work that way. Next, take your battery to a trusty, local ALT/GEN/STARTER shop and have them test it on their special machine under load. The test usually takes less than 5 minutes and there is no charge, pun intended : > ) GRIN. Technically it is Specific Gravity that fails. You can test with an Hydrometer, a large syringe-type device with a clear bulb on the top with 5 or 6 small colored balls in an Acetone solution. The chart you get with it shows what each color and how many are suspended and how many sink. I prefer to let my shop guy do that on his test machine. If a shop test shows a bad/dead battery, plan on investing in a good brand, not a cheap/bargain house off-brand. Those tens to have poor life spans, 2 years is typical. Good brands include INTERSTATE, DEKA, EAST-PENN DURACELL, EXIDE, and a few others. Once you do that the next best investment you can make is to get a good FLOAT CHARGER; the DELTRAN Battery Tender JR; is their 6V version, and about $30. Understanding battery life and how it works is crucial to your machines. The worse thing for battery life is to leave it set for a week or more as it will begin to deplete the electrolyte and lead plate cells. Keep it connected when tractor is in barn, not running so the battery is ready to go when you need it. The constant draining and recharging will kill battery life fast otherwise. Another major malfunction on batteries is the failure to have a correct belt tensioning device attached to the charging unit, whether using a Generator or an Alternator. You will never charge the battery otherwise. Lack of a proper fan belt and correct tension will also affect your water pump. You will have overheating issues as well. Never overfill the cells in your battery but check often to maintain proper level. Be sure to keep a Thermostat in the system as well. Some fellas subscribe to the old farmer's wives tale that removing your Thermostat, mainly in winter, will improve performance of your engine. False. The Thermostat was designed for optimum engine performance. Keep it installed and use correct coolant type as well. Your battery is the life-blood/heart of every machine. Without a properly functioning battery, you will not have much success running your machine.

SPECIFIC GRAVITY TEST w/ THE HYDROMETER:


FORD TRACTOR - FAN BELT TENSION:

DELTRAN BATTERY TENDER JR; 6V VERSION:

Tim Daley (MI)

Use a stupid 6v charger to charge it up if it is low.

The modern electronic smart chargers are so smart they wont charge any batteries that are low.

I believe they are promoted by battery manufacturers to help sell new batteries.

In theory they do a nicer job topping off a battery that is in good shape, but they are worse than a brick when you -actually- need a battery charged up.

Sort of like the traction control feature in modern vehicles, if you cant remember how to turn that -feature- off it ensures you will remain stuck in the snow at idle with no way to get out.

Paul

Thanks all for your information. This is a 720 John Deere with a pony start engine.
I had a new six volt battery which would not accept a charge. I am going to do some
of the things you all suggested and will let you know the result. Right now am thinking
my charger is not effective with a six volt battery, as it works well on the 12 volt setting.
thanks for all the information.