990 battery failure?

[jrdellaratta]

Funny thing happened Saturday: my 990 would not start, even though I used it heavily the weekend before, and she still has only 80 hours on it. I had lights, accessories, etc., but it wouldn't even crank. So I hook up my charger/quick-starter, with zero results. Then I check all my electrical connections, battery water levels, gear neutrality, etc. and no soap. So as a last ditch effort, I pull my truck in to the garage, and attach the jumper cables. Starts right up, strongly, like it was just toying with me.

Now, I remembr seeing a thread a few months back about bad batteries in the 990, but it's prompt start-up seems to rule that out.

Does anyone have a decent explanation for what went wrong? /forums/images/graemlins/confused.gif

 

[RandyK]

I had the same problem with my 790. It was the negative battery cable end that connects to the battery. I didn't even have lights on the dash when I turned the key on. I just bumped the cable and the end broke off. Check the battery cables, and see what you find. My battery compartment is a mess and my tractor only has 175 hours. Everything is corroded. How is yours holding up?

Randy

 

[zuiko]

This all makes me wonder if I should swap out my battery. I hate to replace a perfectly good battery but if it is going to corrode the battery compartment and possibly the radiator I would sure like to replace it. I wonder if a regular Wal-Mart battery would make any difference or if I would have to go with one of those really expensive Optimas to get any benefit.

 

[RobS]

Common problem with the 790. I replaced my battery and cable ends last winter and haven't had a problem since /forums/images/graemlins/smile.gif

 

[Golfgar4]

</font><font color="blue" class="small">( This all makes me wonder if I should swap out my battery. )</font>

Being cautious is one thing. But to swap out a battery just because someone else had a problem is something altogether different.

Don't get me wrong. You need to check all of the cables and the battery case very closely. Especially where the others have mentioned they had a problem.

But if you don't find anything wrong, why spend the money and change it out? Just keep a close eye on it. Make it part of your inspection before you use your tractor each time. You do inspect everything BEFORE you use it, don't you? /forums/images/graemlins/wink.gif /forums/images/graemlins/smirk.gif

I'm all for being careful and properly maintaining my equipment. But I don't think I want to spend any extra money if I don't have to. /forums/images/graemlins/smile.gif

Just my $0.02.

 

[jrdellaratta]

As for corrosion, I had (on Saturday) roughly what would amount to 2 tbsp. of white powder along the front edge of the battery itself, which I brushed away. The battery terminals (althoug hard to reach with my cables) seem fine.

Since I recall hearing something about corrosion being a probelm with the 990's stock battery, I've watched the entire area pretty carefully. (Also, I try and be religious about sweeping away the dust and clippings from the cowling after each cutting op). This means the powder showed up in about 6 days' time. The tray is still fine, but at only 80 hours, I'm annoyed that I even have to worry about this.

 

[zuiko]

I'm just concerned because there has been so many 4xxx posts about the OEM batteries spewing corrosive gasses. This is the first I've heard of it from the 90 series. Not sure if the battery they come with is any different.

 

[Golfgar4]

Please, don't get me wrong. I'd be concerned too.

But rather than just go out and put in a new battery, I'd first make sure that there was a legitimate reason to do that.

I trust all of the information that has been posted. But that doesn't automatically mean that your battery is going to have a problem.

 

[johnbilt]

Hi

Not sure what's going on with your machine. I had to clean the terminals on my 990 last month. They had corroded bad enough that I replaced the positive terminal.

The battery seems to operate fine - No problems like you're describing. I did liberally apply the anti-corrosion spray (red stuff in a spray can), and clean the compartment out real well.

Did you measure the battery voltage ?? It may be possible that the battery would run the lights, but not have enough current to drive the starter and solenoid. Or is your problem related to the safety switch ??

I have had batteries in the past that would play the jekyll/hyde game. They work one minute and then they don't. Usually a shorted cell or bad plate will cause this. Vibration and banging around are hard on a battery. The tractor and light truck batteries have heavier plates to deal with this.

Good Luck

John

 

[yellowsocks93]

Zuiko,

Last week we got a 790 in so it was my job to prep the battery area in fornt of the radiator then give it a repaint because it was so badly rusted. The battery was not defective, but rather a couple of the battery caps were not screwed on real tight.

I replaced my JD battery (original) under warranty with another type of JD battery for free. My 990 came with 2 large caps so I replaced it with the same battery made for our JD 970 with the 6 individual caps and no signs of leaks. I saw white acid around the battery on top so I was safe than sorry before it turned out like this 790. I check mine every week for signs of problems but both the JD Strongbox batteries in the 990 and 970 are fine with no leaks.

 

[nello]

Be safe and get a optima battery.The strongbx is a leaker. After one year with my optima battery,no leaks. After paying $18,000, $100 or less is a nothing. 4210

 

[BGL990]

Agreed. I replaced my stock battery with an Optima within a couple weeks of getting my 990. IMO spending a bit on a decent battery is well worth it to avoid the possibility of messing up the battery compartment, radiator, and whatever else if the stock battery leaks.

I don't remember the exact model of Optima I got - it was whatever Wallmart had in stock (red top). There is lots of room in the 990 battery compartment, and at least in my case the cables were long enough to cross over to the posts which were not on the correct sides of the battery.

 

[jrdellaratta]

OK: now I am completely stumped.

I've cleaned the terminals, checked every connection and the water levels, tested the voltage level on the battery (my meter read 12.6 last night after having the charger on it for the day), and none of this has enabled me to start my 990. I still get dash lights, hazards, and headlamps, and when I tried jump starting it, the best I gopt was a short, 2 second buzz as I turned the key, and then a few short clicks.

All this seems to indicate the problem is not with the battery, but some other cause.

Suggestions eagerly anticiapted: it's Friday and I've got cutting to do tomorrow.

 

[Jim_Fisher]

jrdellaratta,

</font><font color="blue" class="small">( I've cleaned the terminals, checked every connection and the water levels, tested the voltage level on the battery (my meter read 12.6 last night after having the charger on it for the day), and none of this has enabled me to start my 990. I still get dash lights, hazards, and headlamps, and when I tried jump starting it, the best I gopt was a short, 2 second buzz as I turned the key, and then a few short clicks. )</font>

You need to test the battery under load. Most auto repair shops have a tester with a carbon pile that is designed to place a measured load on the battery for a short period of time. If the voltage drops below the threshhold (usually 9.5 volts) then the battery should be replaced.

I suspect that your battery has an internal fault that is causing an open circuit under load, but you need to test it under load to find out for sure.

Can you hook up a VOM (in voltage mode) and monitor it while you are trying to start the tractor?

 

[jrdellaratta]

Tonight I expect to have another pair of hands available to help me through this process. Some free advice I got this AM (fro the local dealer, Gladhill Bros. and an aquaintance who's got yeasr of experience restoring antiques and maintaining contemporary models) also suggested: after testing the battery in the way you suggest, work my way back to the starter. Other advice included checking my safety switch, and RE-checking that the PTO is disengaged, although I expect I wouldn;t even get the "clicking" if the safety switch was a problem.

My own ignorance is adding to my frustration.

 

[Keoke]

Jim is right, battery must be tested under load. The 12.6 volts you see at rest is a surface charge and means very little.
You can use the starter as a load by leaving the volt meter attached while you run the starter. Voltage at battery now should not drop below 9.6, the average reading here is about 10.2 volts while cranking.
To check battery post to cable connection place voltmeter across post and cable. Voltage drop here should be no more then .1 volt at starter load. E.G., red meter lead goes on positive post and black lead to cable. To check entire pos post to starter solenoid cable run place pos meter lead at battery and neg lead on cable at solenoid post. Voltage drop here should be no more then .5 volt at load. Do the same on the ground cable with the max drop here at .2 volt. The normal voltage drop will vary with length of cables but the above numbers should be looked at as maximums. Be especially suspicious of any battery ground cable that goes to the vehicle frame and not the (starter) engine block.
Best to use a digital voltmeter or a low scale analog meter for the above test.
On battery corrosion due to sulfuric fumes from vent caps. Your best bet here is to go with a sealed automotive type battery. Get the biggest one (cold crank rating) you can get to fit the box and accommodate the OEM cable lenghts. Good quality batteries have an "O" ring between the battery post and the case to prevent the fumes escaping between the post and the hard plastic case. These batteries keep under the cable post corroison to the mininmum.
You can also use the anti-acid felt washers they sell in auto parts stores here.

lots of luck,
george

 

[jrdellaratta]

Thx for the tremendous detail and step-by-step process. Will advise of results Monday!