Author Topic: Two problems with MP5  (Read 3381 times)

Offline Guyblat

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Two problems with MP5
« on: February 05, 2016, 04:57:20 AM »
I have two problems, and I may apply for a return/warranty:

1) Various and random spokes will either dislodge, become loosened, or the thread will release hold and the spoke will detach, causing nipple to bounce around in rim until I fix. It has happened 3 times now. No broken steel.

2) MP5 will NOT engage regeneration brake for at least 1 mile when I first fire up bike after charge. If I hold MP5 off ground, instead of setting out, it will NOT engage regeneration, in fact, the wheel will spin faster. Major fault it seems in the circuitry.

Guy

Offline Ecobully

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Re: Two problems with MP5
« Reply #1 on: February 05, 2016, 02:51:57 PM »
#1 might be spokes tightened too much and might need to be rethreaded (on new spokes). I am unsure if it's most cost effective to do yourself or send back--might ask your seller for some sort of reimbursement for your out of pocket costs.

#2 please check your over voltage level and your battery voltage. If you choose 36V when your battery is a 48V, this can happen as the over voltage settings will not allow your regen to trigger. Please make sure that once you get it working to set EBS Phase (A) to a value that meets your needs (regen braking levels -- I chose 35 for most rides)

** Remember to use torque arms (preferably on both sides) when applying regen braking as it will tend to loosen your nuts (from your axle) and simply tightening them further will eventually damage the threads on your axle requiring much more work to repair **

Offline Bikemad

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Re: Two problems with MP5
« Reply #2 on: February 05, 2016, 03:52:26 PM »
1) When a new wheel is first used, the spokes will naturally loosen a bit as they settle in and should be re-tensioned correctly to prevent them from becoming too loose. Some people apply thread locking compound when assembling wheels to prevent the nipples from working loose, but this will not prevent the spoke tension from decreasing as the spokes and nipples bed themselves in to the holes in the hub flange and the wheel rim.

If spokes are severely overtightened, they tend to snap or strip the threads inside the nipples, and I have never experienced nipples coming undone on correctly tensioned spokes.
I usually tension my spokes as tight as I can get them without without starting to round off the square drive on the nipple, and I have never had any nipples/spokes come loose after initially retightening them. It is important to make sure the spokes are all evenly tensioned and that the wheel rim remains concentric and true.

2) It is not good for the battery to use regen while the battery is fully charged as it could lead to overcharging of the battery if the controller or battery's BMS is unable to prevent it.
My Vectrix electric scooter has very poor (almost non existent) regen when I set off with a freshly charged battery and I have to use the hydraulic brakes to slow down gently at the end of my road, but after a mile or so I can stop reasonably quickly using just regen alone, and the Vectrix weighs 210kg (462lbs) without the rider and pillion!

Regarding the wheel spinning faster when applying the brake with the wheel off the ground, does it do the same when the front or rear brake lever is pulled, or does it not make any difference? (Assuming the brake switch operates before the mechanical brakes start to grab.)

Alan
 

Offline Guyblat

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Re: Two problems with MP5
« Reply #3 on: February 22, 2016, 01:34:34 AM »
Thanks you guys.

Alan,

I'll continue to work on the spokes.

That regen answer makes a LOT of sense, the regen issue only happens when fully charged. Freaks me out.

thanks again,
Guy

Offline RooGM

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Re: Two problems with MP5
« Reply #4 on: February 29, 2016, 09:25:01 PM »
If I hold MP5 off ground, instead of setting out, it will NOT engage regeneration, in fact, the wheel will spin faster. Major fault it seems in the circuitry.

Guy

I have the same problem on my Magic Pie 4.  The regen worked on 36v but it never worked for me on 48v.  And like you said, when regen brakes are engaged the wheel actually spins faster.  This happens regardless of if the battery is fully charged or almost done.  I never got to the bottom of the problem.  I removed the regen levers and disabled regen in the controller.  Regen seemed to be doing more harm than good, in my experience.  When it did work on 36v I think it overcharged my battery and killed it fast.  So I prefer no regen at all now.
« Last Edit: February 29, 2016, 09:26:44 PM by RooGM »