"geezer" wrote in message
...
I have trouble starting my rider after it sits a while. If I put my
10A charger on it for some 10 minutes, the mower starts fine.

I find no evidence of a drain on the battery.

The battery is relatively new, one year. I replaced earlier battery
with same problem.

The battery shows 10V when it won't start the mower.

The 10A charger causes my meter to show some 15V at the poles when
charging.

If I let it go for a while, then disconnect the charger, my meter
shows 11-12V at the battery poles,

The charger cuts back normally, but I would expect it to start at 10A,
then drop eventually to close to 0. But, it starts out at only 2-3A!
I am wondering if that is a give-away.

Any thoughts?

It appears to be a dead cell in your battery. Each cell is 2 volts, and
when one poops out, you'll end up getting the problems you describe.

I assume you've checked the water, electrolyte level, cleaned the terminals
and surrounding area of the battery, and tested the mower for shorts.

In case you haven't done all this, first you can check for shorts by using
your meter. Connect one terminal of the battery to the mower. Then connect
one probe from the meter to the other terminal, and the other to the
disconnected battery terminal. With the mower OFF, you should get 0 volts.
If you get any steady reading, even if it's very small, there's a short
somewhere, possibly a dirty connection at the starter or ignition switch.

As for the rest, you should take the battery to a trusty automotive shop to
test and fill the fluids. While you probably can get away with just adding
distilled water, if needed, it's a good idea to check the electrolyte levels
when the water gets low enough to affect starting.

This just might get things working again. If the cell is dead for good,
it's time for a new battery.

Otherwise, usually a dead cell indicates the battery was discharged
completely, probably numerous times. As this is your second battery with
the same problem, it's possible there's either a short in your mower, or
your charger, which appears to be meant for large car batteries, while
smaller batteries are happier with low current trickle chargers. 10 amps is
a mighty beefy current to push in a small battery.

A good trickle charger can be hooked up continuously to your battery without
damage. A cheap crummy one can be hooked up for several hours without
damage, but can seriously damage your battery if it keeps trying to charge
it. A boat shop or RV supply store will have good trickle chargers aplenty.
You might find one at a very well stocked auto parts store, but I suggest a
boat shop, where you can ask the gurus there what's best.

You really shouldn't need one if the mower is charging properly, and it
sounds like it is. Still, it's a handy thing to have around, especially if
you don't use your mower during the winter months. Anyway, 13 volts is
plenty for charging this battery, while 15 volts is close to cooking it.
Your car doesn't even charge at 15 volts, more like 13.5 to 14.2 or there
abouts, and a car battery is a good deal larger. Usually, these things
charge using a dynamo, which is sort of like a built in generator. Performs
the same basic function as an alternator, but not quite the same way, and
not nearly as powerful, which, as I mentioned, is a GOOD thing.

So, check for shorts, check the battery fluids, and if none of this stuff
works, you'll probably have to take your mower in to have it checked out, or
do a makeshift dangling wires job so you can 'jump' your mower.

I very strongly DON'T recommend the latter. If you accidentally cause a
short, you'll be extremely fortunate to be left with melted wires all
through your mower. If you happen to be on Fate's sh_t list, you could end
up with a fire and/or 3rd degree burns. It would take less than a second
for a shorted wire to get red hot with even that smallish battery, and if
your leg just happens to be in contact with it, the doctors will be
scrubbing your leg with a hard bristle brush to get pieces of sock, jeans,
rubber insulation, and melted copper out of your blackened flesh, all in all
very unpleasant business. On the brighter side, you'll learn enough about
burn treatment to keep your friends and family entertained, as well as
nauseous, for hours on end.

It's definitely cheaper, easier, and less painful to find the problem and
fix it properly.

Pagan