I think my E15 knows I've replaced it with a robotic lawnmower
and am planning on selling it. It's trying to sabotage itself.
Let me explain.
When I got home, I used the better multimeter I brought home
from work to measure the voltage of the batteries. The pack read
37.5 volts (3 days after it was last charged). A bit lower than
ideal, so I figured I'd charge it for a while this evening and
measure again in the morning.
I turned on the power strip I keep the charger plugged into,
and noticed the charger sounded "different". After a couple of
seconds, the breaker on the power strip tripped and the charger
shut off. That seemed odd, so I decided to check things out.
While doing so, I noticed that I had left the tractor's main
power disconnect turned off (I think I turned it off yesterday
or the day before when cleaning up the connections on card 1).
So I said to myself "self, you should probably go ahead and turn
that back on" - without thinking it through (after all,
something had just tripped a breaker on the power strip powering
the charger).
As soon as I turn the main power disconnect back on, there was
a "ffffftttt!" sound and a little spark from the charger area,
and the release of some magic smoke. I immediately shut it back
off, and said to myself "&*#%!!!!!!!".
I haven't had time to do any diagnostics yet, since I had to
start making dinner. I disconnected the charger from the tractor
(unplugged its harness), and turned the main disconnect back on,
and everything there seems fine - but obviously something is
amiss with the charger. I didn't do any fiddling with it. What's
weird is that having the charger ON didn't make any sparking or
release any magic smoke - it just sounded different (almost like
something was rattling), and tripped a breaker.
The magic smoke was released (from the charger) when the
charger was *off*. It's been over 10 years since I did anything
with the charger, so I can't remember how it's all wired up. The
behavior seems consistent with some kind of short in the charger
- but why would that matter when the charger is off? Hmmm....
the harness must have the + and - ends of the battery in two of
the connections (so the charger can charge the battery) - I'm
guessing those must have shorted together. I'll check for
continuity between those tomorrow.
Anyway - this thing seems to be trying hard to keep me from
selling it....
In case the charger is fried - does anyone sell rebuilt ones?
Thanks,
Mike
Michael S. Briggs, PhD
UNH Physics Department
(603) 862-2828
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