My new bike with MAC motor, Grinfineon, TDCM sensor

[tanstaafl]

Except the handling will be better with the battery in the triangle--as long as is narrow enough to not affect your pedalling.

It's not as bad as it could be with battery in the bottom of the bags near the axle, compared to up on the top of the rack, but it's better close to the center of mass of the bike.

I agree with all your points. But I think I can live with this compromise location -- it's where I had them on my previous bike except that I was using some really ugly battery bags -- re-purposed office depot logo "briefcases".

If I ever get new batteries, though, I will probably put them in the triangle.

 

[tanstaafl]

Everything is working with the modified CAv3, external PS, and bigger battery. But I'm going to have to adjust something in the CA -- one of the gain parameters perhaps. There's a really bad "pulsing" to the applied power that wasn't there with the lower voltage battery. Some interaction of the gains and thresholds, I'm guessing. What's weird is how touchy the throttle is even when I have it set up in "torque" mode -- I hadn't noticed that with my previous motor. This is hard to say for sure, but the pulsing seemed worse in torque (current) control than in pass-through mode. The pulsing was also there using the TDCM torque sensor for PAS. It was more annoying there since it's harder to compensate for it.

I'm probably also going to tweak the throttle set up so that it doesn't have so large a "dead zone" at the top and bottom of the throttle's range. I think that might give me a smoother control, but I'm going to be cautious with the bottom end of the range. It's more important not to get unintended motor activation. The top end, however, is free game -- I'm not going to be maxing out my speed anyway. I might also consider a better throttle. But all this is secondary -- I'm guessing one of the other software parameters is the main problem.

I'm wondering if I'm really going to get that much of a speed improvement out of the higher voltage -- seems my limit in my commute isn't so much the top speed. It took me about the same amount of time this morning even with the higher top speed. Maybe it'll improve when the throttle isn't so touchy, after I adjust things. But the big limit to my commute time may be all the stop signs and traffic. Bummer.

 

[tanstaafl]

I've been working on my parameters for the new bike -- lately up and down throttle rates and AGain. Yesterday I had a problem where the throttle response didn't seem to start until I had maxed out the throttle. Once it started, it seemed to work over the whole range. Then, mysteriously, the problem seemed to have disappeared today when I went to reinvestigate it.

Over lunch just now, I went to try tweaking the settings some more and the problem came and went. I have no idea yet what combination of things makes it come and go. However, today I was able to restore the settings to some more aggressive values without getting the "pulsing" -- so far, so good. I haven't started on the PAS yet. I'm going to get the throttle fully tweaked first.

I have the throttle set to control torque/current, and so far it seems to hold it steady and not to bounce around too much. I've noticed that when I apply the brake, and power cuts off immediately, it seems to ramp back up really quickly (almost instantly) when I release the brake -- is that how it should work, or should it move the throttle output voltage up at the normal rate? Or is that so fast that I didn't even notice the ramp-up? I'm not sure...

And then a funny thing happened: I was running with the throttle set for about 8 amps output -- watching it on the diagnostic screen with the throttle in and out values displayed -- when I blew a fuse on my battery. It seemed strange to me that it would blow -- I was nowhere close to the fuse value (20 amps). I've been running on the same battery fuses for several months now and this is the first one I've had blow on me. I've normally limited my amps out to values only _just_ below the fuse (really too small a fuse, probably) and never had a problem before. I guess I will go ahead an replace the fuse with a 30amp -- I had planned to do this from the beginning, but the 20 amp fuse never blew. My battery pack should be able to handle 60 amps (actually rated for 69.3 according to the manufacturer of the cells I used) and my controller is a 40 amp, but I just don't use that much power. It just seems a little weird that it blew when I was only trying to draw 8A.

 

[amberwolf]

The most likely thing is that it blew because the current actually exceeded the fuse's limits long enough for it to do so (even if the current metering doesn't show it).

If this happened, and the metering didn't show it, you might want to reverify the shunt calibration, putting another current meter inline with it that has it's own shunt, to see what is actually being drawn.

It is possible for a bad connection at the sense wires from the shunt to the current meter (CA) to cause enough of a voltage drop to not read the current correctly, and appear to be lower than it actually is.

 

[tanstaafl]

The most likely thing is that it blew because the current actually exceeded the fuse's limits long enough for it to do so (even if the current metering doesn't show it).

If this happened, and the metering didn't show it, you might want to reverify the shunt calibration, putting another current meter inline with it that has it's own shunt, to see what is actually being drawn.

It is possible for a bad connection at the sense wires from the shunt to the current meter (CA) to cause enough of a voltage drop to not read the current correctly, and appear to be lower than it actually is.

It's probably a combination of me doing something unusual, having too small a fuse, and the CA not doing what I expected. I don't have a good meter for measuring current, but the CA has always showed my battery usage fairly accurately (amp hours used seem to come close to battery capacity). I hope there's not a problem there. What I was doing that was unusual, was braking without releasing the throttle. I'm guessing that when I released the brake the CA started back at the previous throttle voltage after the wheel slowed down causing an amperage spike. For some reason, I expected the CA to ramp the voltage back up slowly enough that this spike wouldn't cross the amp limit I had set. I'm not sure, but I'm guessing it doesn't work that way?