# 3KW Moped - too slow!



## darkmunk (Dec 15, 2015)

Hi folks, Whilst messing around with various carts and trailers, I took the plunge and bought a little Evomotion-e-3000-rx Evo electric moped.

It's suposedly 3KW. with a 72v 35 amp controller and 72v lead acid battery pack.
It is quite severely limited tho. 
It pops away from the line and gets to 10mph as I would expect, but then it seems to flatten off and loose power, crawling up to 26mph eventually.
This is quite dangerous in town, with drivers getting impatient and cutting me up.
The controller seems to be aware of the wheel speed and won't let the scooter go over 26mph or gain speed quickly above about 10 mph.
If I crest a hill, I expect it to gain speed as the load drops to almost nothing, but it throttles back and won't pull.
It's really frustrating.
I'm sure that 72v and 3KW is more than enough to nip around safely, if I could access it.
I understand that batteries might not last long if I go fast, but that's fine - I only have a 6 mile round trip.
So, does anyone have any experience with these little Chinese mopeds or the controller and can give me some hot tips for disabling the restrictions?
Cheers!

Words on controller spec plate:
Jianngsu Xinri E-Vehicle Co ltd
Sign Motor controller for PMSM for DC72V 12 inch tDd-255Motor
Version: ZWK7235-XR141C-DG
RATED VOLTAGE: DC72 V
PROTECTION V: 64
MAX CURRENT: 35A
BRAKE LEVEL: HIGH
PHASE ANGLE: 60 (DEGREES)
THREE SPEED AT
Code: 0108
Nov. 2015


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## RIPPERTON (Jan 26, 2010)

After voltage drop from crap Leadacids you are barely getting 2kW.
I would be looking at rekitting this out with a few HobyKing LiPo packs and a decent 100A controller. Maybe even keep the same voltage so you can use the same charger.
Pull it apart and show us what it got.


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## dcb (Dec 5, 2009)

yup, 
http://www.evoscooters.co.uk/evomotion-e-3000-rx-evo-electric-moped-scooter.html

top speed 45kph (27mph), 72v, the hub *might* be able to make 3kw, but you will need the batteries and controller to support it. 

If you need cheap and don't mind experimenting, with the weak controller you can try a delta/wye switch
https://endless-sphere.com/forums/viewtopic.php?f=30&t=25136 it is *cheap* and might get you a bit of higher end acceleration back.

but lots of caveats, mainly it might not work, and you mustnt switch back to wye above a certain speed or you will expose your controller to higher than designed voltages/currents.

but otherwise new controller, new batteries, higher voltage pack (so it can push the amps at speed), new charger, can easily cost more than the scooter itself  I wouldn't expect much from just a lithium conversion, it is all pretty much weaksauce.

edit: THREE SPEED AT? seriously, is that a joke?

edit2: lots of stuff on delta wye at ES, not well organized though
https://www.google.com/search?q=del...&ie=UTF-8#q=delta+wye+site:endless-sphere.com


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## Karter2 (Nov 17, 2011)

Its clearly restricted to 26mph by the controller.
Google up a user forum etc to find the hack for the controller to derestrict it.
Someone, somewhere will have done this before
Plan B.. If you have the skills, replace the controller with a known unrestricted unit.


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## darkmunk (Dec 15, 2015)

Cool. Thanks guys.
Didn't realise lead acid was a problem. I thought it was mostly a weight thing with them.
Am I right in thinking I need 60 2200mAh lipos? so about $600 :/
I'll start with the cheap options and try and track down some owners


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## dcb (Dec 5, 2009)

Karter2 said:


> Its clearly restricted to 26mph by the controller.


I don't think so, because it limps all the way from 10mph to 27mph after a strong start, it sounds like it is voltage (BEMF) restricted (which can be addressed by lowering the kv rating with a delta switch or increasing the system voltage)

so star from 0-10mph, "full torqe", flip the switch from wye to delta and get ~60% full torque to 17mph, then slowly climb to 40 or so mph.

I would start with hard wiring it in delta and see what it does above 10mph compared to stock, total cost: 3 wire nuts.


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## darkmunk (Dec 15, 2015)

Thanks. 
I would like to try that. Haven't had much success unearthing more info on delta wiring.
Could you expand a little please?


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## dcb (Dec 5, 2009)

well it is gonna be model specific, and require some futzing, here is an example of the wiring.
https://www.youtube.com/watch?v=C4FcdPsp-aE

the basic idea is to go from the "Y" (wye, star) diagram on the left to the delta on the right.









All the phase coils meet at a junction in wye, and they meet at the controller leads in delta, and keeping them in phase/polarity is critical. Maybe near you in the UK can help? Otherwise if you take it apart and post some decent pics of the stator we might be able to sort it out visually. No guarantees of course 

Endless-sphere.com is also a great resource, probably a lot more experience with this scale stuff there, possibly elmoto.net too but it has been a bit quiet lately.

but in that diagram and the video, they break the wye at N and join the other end of S to R, the other end of R to T, and the other end of T to S, basically lowering the impedance and voltage requirements by adding a parallel element to the windings.


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## RIPPERTON (Jan 26, 2010)

darkmunk said:


> Cool. Thanks guys.
> Didn't realise lead acid was a problem. I thought it was mostly a weight thing with them.
> Am I right in thinking I need 60 2200mAh lipos? so about $600 :/
> I'll start with the cheap options and try and track down some owners


18 LiPo in series (75v).
If you get Hobby King, try to get packs with as many cells in parallel.
maybe 9 of these in series (ebay)
http://www.ebay.com.au/itm/RC-Turni...546415?hash=item25941a5fef:g:UiMAAOSwEK9Tzb~z


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## SfieszaQ (May 7, 2017)

Hi, Yo can do 2 things
- disconect the wire from speedometer. Check your manual. You should have electric drawings. It will remove your speed limit.
- in the controller you can add (parallel) resistor on current monitoring resistor to increase current and replace MCB from 32A into 40A.


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## Jguest71 (Jan 7, 2018)

The attached is the wiring diagram from the manual, I will try disconnecting the white wire link and let you know.


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## Jguest71 (Jan 7, 2018)

White link was already disconnected, connecting it limited top speed to 18mph on centre stand rather than 36mph without. Back to the drawing board.


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## Jguest71 (Jan 7, 2018)

Disconnected what appears to be the speedo wire - speedo stops working no faster  I have just put another 12v battery in series - performance is better. It gets to the limited 26/27mph and stays there, hills dont slow it down as much either. So the controller must be limiting the volts going to the motor as volts = speed and amps = acceleration. Time for a new controller I think - then new set of batteries when the SLA have had it.


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