990 battery failure?

nello · Aug 3, 2004

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 · Aug 3, 2004

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 · Aug 13, 2004

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 · Aug 13, 2004

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 · Aug 13, 2004

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 · Aug 13, 2004

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