Hello all,
Chinese 72v 1500w scooter, new throttle, six new 12v 18amp batteries (replaced 12v 20amp batteries), new 72v controller from Zenid (thank you Z), and now running again.
PROBLEM:
The thing has little power and the phase wires get hot QUICK. I upgraded to 12awg phases from the controller to outside the hub axle because of this, and they still get very warm.
I spin the motor on it's axle and it's a bit tight, kinda grips the wheel and stops it right before the end of a hand spin. I took it apart, inspected it, saw some slight rub marks, checked the bearings by hand and saw terrific free spin (when apart). put it back together, tried all allen bolt configurations and it still spins poor. kinda grippy (is this normal for sealed bearings with dirt protector?).
QUESTIONS:
1. How do I check for controller output under load (shouldn't drop right)?
2. Could the drop in amps from 20 p/battery to 18 p/battery affect its power this much?
3. What could make the phase wires get hot even after an awg upgrade and battery amp drop?
4. Would a motor replacement stop this and make it run like it should?
It still has kinda a grindy noise when under load at the take off too.
I have looked to golf cart repair people, e-bike guru's online and in town and NOONE will even look at the thing for under $75 an hour (it would take tthat just to understand anything about it).
I'm about ready to roll it off a high cliff under it's own slow power, or light it on fire and then do the previous....aaugh!!
any thoughts that could lead me to the culprit would be appreciated and here's a wire diagram plus open wheel pics
Thanks all for any help and/or thoughts
Steve'out
You should define "little power" for starters. Even "powerful" scooters with 5kw or more don't have a lot of guts when they use hubmotors. How fast will it go, and how long does it take to get there? Does the motor housing get hot, or just the wires?
OK my bad, "little power" meaning just enough to get the scooter going on a level ground, and "hot" as in when I feel the wires they are more than warm.....to the touch (before with the 16awg wires they melted together after just 5 minutes of riding (slow, as in 5-10 mph)
How can I tell if bearings go bad? ;)
Once ( again )-----Grinding noise ----- low wattage to the motor----Also Battery pack must reach at least 80 volts after charged . Thin steely wires melted at contact thru sparking (faulty connection) everything gets hot. Test each battery UNDER LOAD (stick the wheel and throttle carefully ) Good luck. No I mean 18 ah batt would be weak for 1500 (good for 800-1000) watts motor if controller does not recognize If you got SELF-STUDY wires plug- unplug until works right .
Most probably either two or all three phase wires are switched from where they should be, or the hall sensors are not connected in the right order.
Low power, lots of grinding noise and extremely high phase currents (and thus overheating cables) are all typical signs of misalignment of phases and/or hall sensors...
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
Hi Stephen
Keep at it mate, im sure you will find the solutions to all the problems in time.
i have just come across this forum, i too have one of these scooters for my girlfriend, all the way over here in New Zealand.
its sluggish on start-up but it does go.
it took me a long time see and work out how the system for charging works, and even that they have 6 batteries.
I have some questions that i hope will help give you answers to your questions:
one) do you know if your motor is electrically sound? - i think you should be able to your digital multimeter and measure the resistance between the phases of the motor, and if they do not read all the same, you have a problem there.
two) when you had three batteries swell because of over charging, was it three batteries that make one 36v pack for charging? - if so, this could point to the relay as it is the relay that isolates/switches the battery packs. and so what if there is a high resistance joint on or in that relay that is preventing the controller from getting the voltage it needs under load? I would image that would give you very little power at the hub, and maybe compensate with high current that is melting your wires.
what do you make of that?
on my girlfriends one - the battery gauge died- needle would keep geting stuck, and then the barrel of the ignition fell to pieces.
this gave me the opt unity to take the hole thing apart to find out how it works. (do you know if the dc-dc converter works on 72v or 36? - every time I look I get confused)
i plan on disconnecting the batteries to see if any are weak, perhaps doing the shunt mod menchend on this forum, and adding a 7th battery as a boost, using the start button (currently wired as a second horn)
take care and good luck
Michael.