Today I replaced the passenger front brake line, now the bus no longer swerves left when I step on the brakes. Diagnoses was easy - when I first got the bus, it swerved to the right when I stepped on the brakes, and it turned out to be the drivers front brake line. Too bad I didn't replace both at the same time
I installed the brake vacuum booster. I 3/8"-1/2" adaptor from brass plumbing parts I bought at Lowes, and hooked up the booster to the existing vacuum lines. It blew the 20a fuse I had connected to my main power line (the fuse on the booster itself is 25a) but a 30a fuse seemed to run OK. It never shut off though, so I probably need to replace all of the original VW vacuum line (sigh). Worse, the pump seemed to spew oil; I have to track down THAT leak. The manufacturer warns to never set the oil-filled muffler on its side - and I never have - but gotta wonder about what other problems the oil-filled muffler could introduce. It was reasonably quiet though.
I bought the new high-current CA from Justin. I couldn't easily find a project box that was the right size, so yesterday I ended up cutting up the plastic case of an old UPS to fit and mounting it to fit. So, with the new CA in place I ran another test with the new batteries, and I youtubed video of the run below. The shunt setting was already at .5000 and in high-current mode from the factory, but oddly again the continous battery-side drain the CA was @40a, spiking up to 60-70a occaisionally. It consumed 145wh is about 1.2 miles.
I am concerned that I was only seeing 40a, because if it was off by a factor of 10 - then I would be burning 1,450wh in a mile and this project will be unviable, and a failure. I checked the voltage on the video - at 50a the cells are @86v, so that would be 30 firstname.lastname@example.org, reasonable for 5c or 400a, low for 500a. My 400a silicon fuses should have blown at 500a though, and the batteries should have heated up instead of remaining cold.
Edit/Update: On a whim, I changed the default shunt setting to .0500; looking back in this thread, I see that I did that with the last CycleAnalyst on page (6). This new one is the high current model, designed for an external shunt, so when I saw .5000 I just assumed it was set correctly. It was not! Now, I see amp values jump up as high as 419a, but not a factor of 10 like .5000 vs .0500. Because there was a lot of traffic I didn't do the full mile, more like .85 miles, and consumed 527wh. That isn't fatal to the project like the 1,450kwh/m I extrapolated from the 145wh/m I got at 0.500, but it is worse than the 500wh/m I considered to be my worst-case scenario. This makes me wonder about the wh/m numbers I have seen posted by folks with lead-acid bus conversions, I'd rather fail and publish the results than lead other builders astray with false numbers. As it stands, it seems pretty likely that I am going to need to go to 180v for the pack to have enough Kwh to do my full daily commute.
On the other hand, that .85 mile course did include (5) stops, so it real-world consumption for my commute might not be so bad. I think I might also find some effeciency when I change the transmission fluid (gear oil) to something lighter, and doing the wheel bearings etc helped comuta-car folks a lot, I might get under 500wh/m. Since my commute includes a trip home for lunch, it is possible efficiency gains and a lunchtime opportunity charge could get me there. Or maybe I just do the morning commute in the VoltsBus and the afternoon commute via ebike. Or maybe I will have to fall back on the original Comuta-Car project.
So anyhow, here is today's video: