This blog documents the restoration, and conversion, of a 1965 Humber (Singer) Vogue to a fully electric vehicle. The Vogue will be powered by an 11kW(modified), 3 phase industrial AC motor, controlled by an industry standard Variable Speed Drive (VSD) or Inverter. To be able to produce the 400 volts phase to phase the VSD will need about 600 VDC of batteries. A big thanks to the contributors on the AEVA forum:

Wednesday, September 18, 2013

Pack problem caused by Water

As soon as I got home from work last night I yanked Pack #5 from the boot (trunk), took it inside and pulled it apart. There was a little bit of water on it and a few drops on the tray but I kind of ignored them until I got the pack apart - a little water dribbled out but I still wasn't sure that it didn't get on the pack when I was removing it (boot lid was very wet). I checked all cells and all measured 3.27V per cell - no variation. So the cells were OK. I proceeded to remove the bottom of the pack enclosure - now it was obvious.

Most of the bottom cover was covered in a thin film of water with a patch about the size of a matchbox (50mm x 40mm) that had green tinged foam/slime around it - that's where the BMS's daughter board was sitting in the pool of water!
BMS daugher board circled in red. (Daughter board appears to be so they can use the same BMS for 12 or 16 cells systems. They add four more cell handlers on the little board.)

Unfortunately my sense of WRONGness was so great I instantly wiped it all up - then remembered that I should have taken a picture - oh well.

I removed the BMS board and cleaned it with genclean (PCB cleaning stuff) then resoldered any suspect looking pins (a couple of Molex pins looked like they had corroded slightly), then gave the board a coat of clear laquer.

OK - so where did the water come from.
Some while back I crowed about how the Vogue was fine charging in the rain because the charger inlet (located IMMEDIATELY above this water soaked pack) had a "moat" that went to a drain hose. Well the 48 year old drain hose had cracked even more than when I re-installed it and was leaking every time I charged in the rain. Also, any water that got under the unsealed cover while driving went down the drain hole/hose.

The charger inlet, "moat" and drain hole in question.

I cut the bad end off the hose and ran the hose in a straighter line (no fuel tank to go around).
View inside the boot.

This old picture shows where Pack #5 is mounted with respect to the charger inlet. It's the one sitting alone on the left under the contactor/fuse box.

I haven't tested the BMS board yet to see if it still works - fingers crossed.
I'll try to get the pack back together tonight - it's still in the state of the first picture in this post.

When I re-install the pack (assuming the BMS is OK) I will put a temporary cover over the pack and check it regularly for a while.
I am still amazed that the water had got into the pack enclosure so easily. The three packs under the front of the car (engine bay) have been sealed with waterproof gaffa tape but now I wonder about them as well. At least their orientation would not have the BMS board at the bottom of the pack like this one.

...and yes, I am very embarrassed.

No comments: