<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style type="text/css" style="display:none"></style> </head> <body dir="ltr" style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;"> <p><br> </p> <p>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.<br> </p> <p><br> </p> <p>Let me explain. <br> </p> <p><br> </p> <p>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. <br> </p> <p><br> </p> <p>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).<br> </p> <p><br> </p> <p>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 "&*#%!!!!!!!". <br> </p> <p><br> </p> <p>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. <br> </p> <p><br> </p> <p>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. <br> </p> <p><br> </p> <p>Anyway - this thing seems to be trying hard to keep me from selling it.... <br> </p> <p><br> </p> <p>In case the charger is fried - does anyone sell rebuilt ones?<br> </p> <p><br> </p> <p>Thanks,<br> </p> <p>Mike<br> </p> <p><br> </p> <p><br> </p> <div id="Signature"> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <div> <hr> </div> <div>Michael S. Briggs, PhD</div> <div>UNH Physics Department</div> <div>(603) 862-2828</div> <div> <hr> </div> </div> </div> </body> </html>