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Re: (ET) How often to charge large frame tractors sitting idle?

Some basics: At the end of a charge cycle, the voltage should be around 43 volts while the charger is still running, just before it shuts off. Once the charger shuts off, the voltage will drop back over a number of hours to around 38 volts ("resting" voltage).
So need to know when you measured the 40.8 volts to figure out what it means.
As for the 36 volts from battery to frame, it may or may not be significant. Typical electronic meters have very high impedance and can read stray voltages even when there is essentially no leakage. Put a small load (1K resistor, or perhaps a household light bulb) in parallel with the meter leads and see if the 36 volts still shows up. If so, then the batteries may just need a good washing - the thin layer of electrolyte splatter and crud on the outside of the case is conductive. Or look for chaffed and shorted wires (especially the wires that run under the frame near the tranny pulley and belt).
PS I've changed how I'm subscribed to this list as replies to my "no reply" address would sit in my spam box for a long time before I noticed them... hopefully easier this way. 

Steve Shore wrote:

I have a set of 4 year-old batts in "Scary" - the E20 that has been a
ton of work. I plug in the ET charger and it brings the batts up to
almost full in the green scale. A day later the needle is less than half
w/o using the tractor. My VOM reads around 40.81v after fully charged.
The VOM also reads, and I am typing this from a 3-day old
measurement/memory, around 36v from the + post on batt #1 and the neg
VOM lead to the frame. Is that obvious evidence there is a short at the
frame?

On Jan 19, 2012, at 8:54 PM, Jim Coate wrote:


On 1/19/12 7:23 PM, John J Casey wrote:
> ... I set the on-board charger for a full cycle no more than once
> per month; got this from Gunn.

The bad news is that if batteries are fully discharged (ie "empty")
then they can freeze in cold weather - the electrolyte is basically
water.

The good news is as long as they are fully charged before storage,
they won't freeze as the electrolyte is much more acidic with a low
freezing point (like minus 20 or so). And the cold slows down the
self-discharge rate.

So I'd run a charge cycle once or twice over the winter, similar to
what Jack said.