No one has any XL’s to start with. They have not shipped yet.
yeah I was more directing the question to guys who got multiple sets and may have decided they don’t want one
no, XLs haven’t been produced yet, everyone that ordered them are still waiting.
the SDs, yes they’re out there.
If someone wants to sell a set of speeddrive r pm me
i thought you were only selling completes going forward
Does anyone have some tips on focbox settings to get better braking? Have a v4 speeddrive R with a 10s4p 30Q pack (Upgrading to 12s soon) 97mm wheels Running latest Ackmaniac firmware (3.102) with FOC.
Current settings: Current no reverse with break Motor max 60 Motor min -60
Battery current max 25 Max regen -10
Just basic settings for testing, but want to change the motor max and min to 75 -75 and battery to 30 and max regen to -16 or -20. Any opinions or suggestions on getting better brakes?
Diet 
The only things you can do is increase motor max for low speed brakes, and increase batt min for high speed brakes. Motor temperature sensor should help protect the motors.
For batt min, 30q has 1.5a safe charge, 4a max charge. At 4p max is -16a total, or -8 per motor. So at -16 per motor you’re already at 2x the manufacturer specified max. Personally I’d keep going until brakes felt at least somewhat safe, but with the understanding that I could shorten pack life or even cause a fire. IMO.
Other ways to get more brakes:
- diet
- XL (but I don’t think it’ll be a dramatic difference)
- 4wd
- add mechanical brakes
- battery pack that can take more regen current
EDIT the cells can probably take a lot more regen if they’re say below 50% full. The more full they are the more they’ll not enjoy high current charge.
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I have this same problem with the speed drives. They are fun but riding when sudden hard braking is needed can be sketchy. With all the cars not paying attention it can be dangerous riding fast in the city.
wondering where you read that. ? sounds logical but never read about overcharging cells and at different states of charge. anyone do testing? maybe lipos will last longer given how much people expect of ion cells on a board sometimes.
From one of your ES links hummie.
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You also forget the Regen is 20% efficient at best.
Disclaimer: These are second hand V4 that I purchased from Exiledd_Top, and found out after I purchased that they are apparently the ones that were involved in “the crash”. So I don’t know what he has done to them or how much was replaced etc etc
Because these are second hand I took the cans off today to have a look and make sure everything was good. Also because I was curious. While I was looking around I noticed the hall sensor wires on one side had been glued in place at a bad angle causing the wires to touch the outside plate that spins with the can.
I can imagine a stationary wire touching a metal plate spinning at a high RPM will eventually eat away at the plastic and create a problem.
Because the wires are glued in place at an angle pointing them away from the center of the axle where they pass through to the outside. I pulled them off and away but if the cable gets pulled from the outside then the wires get pulled back into the side. So I will need to glue them in place to prevent them from being able to touch.
For comparison here is the other side that has no issues.
Because the wires are glued in place facing the center of the axle already, they are unable to touch anything they shouldn’t, even if the wires are pulled from the outside.
Wanted to share in case anyone else has this issue. Warning, if you take your can off you will need a metal sleeve to slide over the axle so the bearing in the cans are able to glide back onto the lip it sits on. Without it the magnets pulling will make it quite a challenge to get it back in place.
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I wish I forgot but I’m just plain ignorant. I’m kind of scared to go down the regen rabbithole. But I’m so curious about voltage, etc…
So when vesc reports -16a battery current in telemetry, it’s not -16a on the battery wire? I can imagine an 80% gap during regen between motor amps and battery amps, but would have though live data about battery amps would be about in the ballpark?
where’s all the energy going if it’s only 20% efficient?
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I’m not an electrical engineer, but I’m sure the electrical looses, and the energy needed to actually stop the motor is what’s most of the 80%
i thought it was more so a bunch of energy stored in the motion of the board with a person on it that would be “returned” to the battery. the conversion from motion to electrical energy in the motor should be as efficient as if it were the energy being converted the other way.
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It’s been a week on the mill, what’s your estimated time per part? I’ve got 3 weeks till I’m fully healed, and I really want to be on these drives when I come back.
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If you’re putting current into the motor to slow it, you’re still using energy.
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I think hummies point is that the energy has to go somewhere. Initially during acceleration, energy stored in the battery gets converted to the kinetic energy of the moving board and person, but during braking, if only 20% of that energy is returning to the battery, then the remaining 80% has to go somewhere else. I’d assume heat, but that seems like more than is reasonable. The issue is even worse if you apply power to the motor to slow it, since you are expending even more energy that will end up being converted to some other form(heat?).
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Regenerative braking does not put current into the motor. It’s the same as holding the motor in your hand with the 3 phases connected together – it’s really, really hard to turn. The mechanical energy is being converted to heat in the phase wires (and windings).
If you instead connect it to a battery through 6 one-way junctions then the battery will be charged by the mechanical motion.
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