SB Cruiser now accelerates faster, about 4 seconds to 20MPH from a stop. Maybe 4.5.
The upgrade was slightly complicated.
I started out by taking the Grinfineon 12FET off CrazyBike2 (used to run it's front 9C), along with it's righthand throttle. Eventually I'll probably get the bike fixed up into an ebike again. For now it is not rideable by me, as it has no controller for the one motor left on it (front 9C), so while it could be pedalled, I couldn't do it (it'd have to be in the lowest gear which is too slow to balance).
I used the throttle from the above to replace the one on SBC that I broke the tab off of, as I havent' found a way to make a replacement tab that stays in place without disassembling the throttle to mount it from the inside. (several ideas that work that way ought to fix it).
The Grinfineon is not sensorless capable, so it can't be used on the MXUS 3k until I install hall wires in the motor (it has halls that work, but since neither controller I had on the trike at the time could use them, I only installed phase wires when I rewired the motor, to simplify that and save me effort and time).
The Grinfineon *can* be used on the HSR3548, as that does have hall wires (used to be on CB2's rear wheel). So that's where it'd end up going--but not the first stage.
First stage was to open up the "40A" controller already on that wheel to help it get from the 30-33A it actually gets to what its' supposed to. It has 3 shunts, so adding a fourth similar one should up the current to around 40-45A. No place to actually solder one, so it'll just have to parallel with an existing one.
Side note, this is a 15FET, not a 12FET; don't know why I always seem to think it's a 12FET when I mention it.
I dug thru my box of dead controllers, and pulled a shunt off an unfixable one,
then soldered it to the side of one of the existing shunts.
Using this on the same wheel it's been on, the HSR3548 (rightside), it now pulls 46A. It took about a second off the regular two-wheel acceleration time, around 6 seconds-ish. By itself it takes about 12 seconds. (0-20mph). Braking is slightly harder, too, just enough to notice.
Kirin doesn't really care...just wants to hang around me.
Stage two, move this controller to the MXUS 3k 4T (leftside) in place of the other 30A sensorless controller. Easy enough; I left it physically bolted to the same spot, just changing which handlebar throttle controls it (leftside now), and which motor it goes to. Tested just to be sure it worked offground, then proceeded to...
Stage three, pulling off the 30A 12FET generic, and replacing with the 40A 12FET Grinfineon. This gets wired to the the rightside throttle and motor (HSR3538), then had to find the right hall/phase combo. This turns out to be B-B G-Y Y-G for both hall and phases, but it only spins in reverse. There is no smooth forward combo.
Thankfully the controller has a reversing wire, though this messes up my original simple plan of wiring *both* controllers to the reverse button on the bars for backing up. (will now need a relay for this side, or a new button with DPDT NO/NC contacts).
Road testing shows about 4 seconds 0-20MPH with both motors WOT, 103A peak.
Individual controller testing shows
rightside HSR3548 + Grinfineon = 42A peak, ~12 seconds 0-20MPH.
leftside MXUS3k4T + modded generic = 46A peak, ~7 seconds 0-20MPH.
Couple of oddities with this:
46A + 42A is 88A, *NOT* 103A, but 103A is what I get when I use both at the same time.
If anything I'd expect *lower* peak current using both at the same time vs individually, but that's not what happens.
With 7 seconds for one and 12 seconds for the other, separately, it seems like a really big improvement getting 4 seconds using both at the same time. I'd guess the increased battery current has to do with that, though exactly how the motors interact to get this I don't know.
But the increase in acceleration is significant, if not quite as much as I would like yet (<2-3 seconds is my eventual goal...I'll probably want under a second once I reach 2-3
Braking is going to take some getting used to. It's just enough harder to notice, but the real difference is that now the active braking (EABS) is on the left side, and plain regen is on the right. That means the trike pulls hard to the left now, rather than right, so I have to change all my counter-steering reactions during braking to overcome that--I'm using to steering a tad left during braking, and now that would be a bad reaction to have. :/
I knew this would happen when moving them, but experiencing it vs knowing it are different things.
Because the regen current of one motor is partly negated by the power used on the EABS of the other motor, the peak regen current is only around 21A. I haven't presetnly got separate braking switches for each motor, so I can't separately test for how much current is used by EABS, and how much is regenerated.
Because I already had Anderson PP45's on the generic 15FET and HSR3548, I opted to just splice on some to the MXUS 3k4T and Grinfineon 12FET for now, rather than wiring direct as they had been before, on their respective motor/controller. The connectors and the wiring heat up significantly though not problematically, with all the acceleration and braking. The hall wires on the Grinfineon/HSR3548 are directly soldered.
The wiring from the Grinfineon is especially long, maybe three feet +, so I think I'll end up shortening the phase wires and removing the connectors (directly splicing the wires), once I've tested the trike a little more (make sure nothing is gonna blow up on a more normal ride). That should eliminate some of the wire heating, and improve performance just a tiny bit (probably not noticeably).
I'm not sure if it's sag at the battery itself (need to put a voltmeter directly on it) but at the CA shunt it drops from 54V start to 46v under max load, finally ending up after a few minutes of testing (about 2Ah worth of battery) at 53v.
There's a few points at which voltage could be dropping from resistance:
--battery cutoff switch up by pedals
--circuit breaker inside cargobox
--anderson sb-50 connectors at either end of circuit breaker and between battery and main wiring harness
--smaller gauge wiring (12?) between cargo area and battery cutoff up front.
I can eliminate the breaker easily by just plugging the SB50s at either end of it together, bypassing it. The other stuff requires more work, so I'll wait to see the results of the voltmeter test at the battery terminals first, then measure drop across each segment of wiring after that if it's not just battery sag.
Oh, and the very short test rides (just up and down the street) resulted in wh/mile over 118! So I think I'll be seeing significantly higher power usage on my work commutes, as there are around a dozen stop/starts each way, in about two and a half miles each way. Then I should see more like "normal" power usage on longer trips with less stop/starts.
And Kirin is still bored
and so is Yogi
Eventually even Kirin gave up
But I wasn't done yet...
The Grin LED headlight is basically cast from epoxy. However, the AZ heat has apparently softened it to a rubbery consistency, kinda hard but tearable rubber. So vibration eventually tore thru the screwmount, with gravity helping to remove it entirely.
The broken off piece is flexy.
Since I don't have any adhesives that will glue a new bracket to the light's epoxy housing, and I don't know where the electronics are inside to drill a new hole, if there's even room to do so, I just used a ziptie around it and the old mounting bracket. It probably won't hold because of the flexibility of the epoxy, but it'll do for the moment.
Another light that needs a new bracket is my left front turn signal; the plastic has been broken for a long time, and I've glued it unsuccessfully (broke along new fracture lines), melted it together (broke at the now-more-fragile melted lines), and ATM is just held on with electrical tape.