I have my chair set up with a variant on the BM 'charge from vehicle' setup... Instead of using SB-50's on the chair end like he does, I use four PP-75 shells (they use the same pins as the SB-50) arranged into a square block... I have always thought this was slightly better as it made for a more compact and neat setup.
Electrically it's the same thing... Instead of a long jumper wire w/ an SB-50 on each end, I have a small block with a short jumper between two pins. I also added a 24V 'outlet' of AWG 10 wires to a pair of the smaller PP-15/30/45 plugs which I use to run my cordless drill or anything else than needs chair power...
Last night while driving home, I had the chair plugged in to charge, and when I hit a bump my jumper block fell off the place I put it and landed somewhere on the van floor...
When I got home I could not see where it landed to try and retrieve it 
- the chair doesn't move for crap on the 12V charge cable, let alone w/o any jumper at all...Trying to figure out a way to deal with this, I came up with a solution that worked w/ my setup, but probably would not work for BM.... I pulled out my Leatherman multi-tool (never leave home without your pocket toolbox...
) and jammed the tips of the needlenose pliers into the appropriate adjacent pins on the PP-75 block... It was a real pain as I needed to hold the pliers just right, and any bump or wiggling moved them, but this let me power the chair enough to get into the house... I was then able to transfer into my manual chair and go back out and do a more thorough search...I found the plug and all is now well - and I now have it fastened to the chair frame w/ a leash - so it won't get lost again...
I highly recommend adding a leash to the jumper, as it is a real problem to lose it otherwise.....
ex-Gooserider
