New Kubota Battery maint free boiling out acid

[stevenf]

Has anyone experienced their new maint free battery particularly Kubota's boiling out acid (a lot, enough to run all the way down and cover the lefthand side axle completely). The dealer checked the electrical system at start up, at higher rpms and over a couple of hours and it never exceeded 14.5 amps but the battery has continued to boil acid out. The mechanic says that sometimes they just overfill them and it shouldn't do it anymore but since its brand new I'm going to make them replace it as a new one cost $200. and if there is something wrong with the battery I'd just a soon have it replaced through the warranty instead of my pocket.
Steve

 

[btolle]

I think you meant 14.5 volts, not amps.

Check the battery fluid now that the tractor has been shut off for a few hours, the fluid level is low then the battery is not the problem.

It is possible that the voltage regulator is bad. Once the battery is fully charged the charge rate should cut back to something less than 14.5 volts, probably around 13.7 volts which is what a 12 volt battery puts out when fully charged. If the voltage regulator is defective it could be causing the alternator to continue to try charging (overcharging) the battery and that will definitely cause the battery to boil over.

(Somebody correct my numbers above if I am wrong.)

Frankly, I think the mechanic may not really be trained in electrical work. Time to go to the service manager or the owner of the dealership and have a chat.

I hope the paint was not eaten off the axle or anything else. If it is they need to take care of that too.

Bill Tolle

 

[v8dave]

Why did you replace the battery? Unless it was just a 4 or 5 year old battery that came to a timely end you may have the same problem with the new battery as with the old battery. If you were continually replacing water in the old battery, you've still got the same problem.

If, in fact, it was still charging at 14.5 amps after an hour, Bill is correct you have a voltage regulator problem. Unless you have to crank an awful long time to start your tractor, the charge rate should roll off after an hour to no more than a few amps.

 

[stevenf]

Your right Bill I did mean volts and man am I stupid. I was dealing with the Service manager and your right he is very good on mechanical but I don't know about his electrical background but your right and I'll check it myself with a digital meter and see what it does. He told me specificly today that it never went over 14.5volts no matter how long it ran and your right unless there is a lot of electrical usage that would be way to much to be charging a 12v battery full time with no additional electrical load discharge.
Does anyone have a precise 12v+ that the regulator should go down to once the initial charge is replaced from startup. I would think even 13.7 high if its daytime and there is no other energy draw although there is bound to be some electronics running in the ignition system to keep the regulator at a set charge for those systems.
I haven't looked at the battery but Kubota claims its maintenance free so I haven't added any water to it, it just boils it out anyway but that will soon cease when it dries up and fails as will happen to the new one if the regulator is hung like it sounds like it must be. The folks from Kubota battery mfg/or the folks who make the battery for them and relabel probably aren't from Texas where even sears finally gave up years ago on a completely maintenance free because our heat just eats battery's in the summer.
Steve

 

[WhiteRock]

Steve,
The charging system will try to maintain a voltage between 13.5 and 14.5 VDC. The voltage should only change if there is a heavy load on the system or during high temperatures. If the engine is started from a cold start and the negative terminal remove from the battery, the voltage should read above 14 VDC. But I would not expect more that 14.5 VDC.

If the voltage is above 14.5 VDC, I would say that is your over charging problem, especially if this voltage is maintained with a load (battery back on, lights on, etc). If the connections look good, this would be caused by a bad regulator.

Good luck.

 

[skent]

I had the same problem, but mine wasn't maint free battery. Battery was filled to the top line (on the side of the cells). I lowered the level to just over the bottom line. Charging voltage was always in the range of 14 to 14.25, as specified in the manual. But occasionally top of battery had acid on top by the vents.

Always had corrosion in the battery tray and on oil cooler lines. Replaced the battery last month with an optima. Problem is gone and the engine spins over faster than it did when tractor was new. Optima was $119.00.

 

[rockyridgefarm]

Me too, the optima is cheap, compared to the damage that the battery can cause, even under warranty (transportation, loss of use...)

 

[skent]

My thought was the replacement cost of the radiator (close to $400.00). A friend has used Optima in his restored cars for years to minimize damage from acid. The Optima looked like a very good choice.

 

[Soundguy]

If the battery had a bad cell it might boil over.. and also be making the alternator charge onhigh. I would say grab a specific gravity tester.. however with a sealed cell.. hard to do that. Keep an eye on the new one.. if the new battery boils over.. I'd be inclined to think alternator problems.

Soundguy

 

[BobCorazza]

All good info... 13.5 - 14.0 (+/-) is a reasonable charging voltage. I would remove the battery and put it on an automatic charger and see what happens. If it continues to charge at a high current rate (charger specific) I would replace the battery. If the current declines (assuming a constant voltage / variable current style charger) and shuts off or otherwise indicates a full charge then your tractor charging system would be the culprit.

I replaced the (new) Kubota battery with an Optima last year. Top notch battery IMHO.