Sunday, April 24, 2016

Battery Pack Failure Prevention

In my first YouTube video I showed the failure of a power tool battery pack that I had rebuilt with new cells I bought online.  The cells have great capacity and long life, but they have one problem.  The thin plastic heat shrink coating fails if the cells rub against each other, causing an internal short that causes the pack to overheat and fail.

In this video I show how I added paper separators between the cells to prevent the failures.  I cut paper strips and slid them in between the cells of the existing packs, in a winding pattern, to prevent shorts.  At the end I show how I wrapped every second cell with individual pieces of paper when I built a new battery pack.

Sunday, April 3, 2016

Craftsman Garage Door Opener Remote Repair

My Craftsman pocket size key chain garage door opener remote quit working.  In this video I take it apart, diagnose the problem, and repair the remote.  I also show how you can check if the remote is transmitting using a software defined radio dongle.

I found a bad solder joint, but the solder joint was not cracked, it looked more like the solder never properly flowed onto the part lead when it was soldered, so that was probably not the reason the remote quit working since it was likely manufactured that way and had been working for a couple years.  

Shortly after I bought it, the little plastic loop on the corner where you attach your key ring broke off, as I am sure happens to every single one of these things ever manufactured, so I replaced it with a small loop of large paper clip wire that I bent into a loop shape.  It turns out that one of the ends of the wire loop had been hitting the circuit board and wore through a trace.  I show how to repair the trace, resolder the bad joint, and fix the problem with the wire loop so it doesn't happen again.