TSDZ2 750w losing power on hills

[Sasquatch260]

I'm thinking that the fact that you've got a code would mean the controller is working properly.
The code may reappear after a reset, then it would be a pretty good guess that there's something wrong with your motor.




If you can access your 3 Fat phase wires going to your motor, you can test the resistance to see if any are shorted. (like if the coil wires overheat and the lacquer melts)

I kinda forget the details, but I know that you can test an unpowered motor with an ohmeter.

I just asked ChatGPT and it told me how to test. I'll give it a try. Thanks!

 

[Sasquatch260]

OK. I fully charged my battery again and checked it with the voltage meter. It read 53.2 v.

This time, my display read 52.2 V.

The assistance was still minimal. When I tried to pedal up a hill the display voltage dropped to 49.7 v.

I won’t have time today to tear the motor apart and do any testing. I appreciate all the help! I’ll keep you guys updated and please pass on any more thoughts if you have any.

 

[PCeBiker]

That says bad battery to me.
I think you've got some bad cells or cell groups.

I think the BMS is shutting down the charging because one of the cell groups reached 4.21 volts, so the charging stopped.

Trying a known good battery is probably your best bet.

 

[Gionnirocket]

Well 53.2v is not a full charge. Check your charger output with the volt meter.
If the charger is out putting 54.6v then your battery may have an issue.
A 2v voltage sag under load is not unusual... But it also depends on the battery.
Do you know anything about it? Size in amp/hr?
Post a pic of the battery spec tag if possible.
Still a motor overheating and no power seems odd with the battery only sagging 2v if the battery was the issue.
Does the display show amp or watt usage in real time?
If so take note of that.

 

[PCeBiker]

A 2v voltage sag under load is not unusual... But it also depends on the battery.

It's not really under load though.
He says that it's still gutless but still has a 2 volt sag.

So, maybe it is the motor drawing huge amps because it's partly shorted out ?
(It sounds like the battery has issues too though?)

 

[Sasquatch260]

The charger output read at 54.1 V
Unfortunately the display does not show wattage or amperage.

 

[Sasquatch260]

It's not really under load though.
He says that it's still gutless but still has a 2 volt sag.

So, maybe it is the motor drawing huge amps because it's partly shorted out ?
(It sounds like the battery has issues too though?)

That’s what I was wondering… If the battery was already on its way out and fried something in the motor. I’m not sure if that would be causal or coincidental.

 

[PCeBiker]

That’s what I was wondering… If the battery was already on its way out and fried something in the motor. I’m not sure if that would be causal or coincidental.

Or the motor frying stressed the hell out of the battery by pulling huge amps out of it?
Your controller is giving you an over amp error code.

Perhaps your controller is allowing some power to get to the motor so the ebike can limp home to get fixed?
(My car does that.)

 

[PCeBiker]

The assistance was still minimal. When I tried to pedal up a hill the display voltage dropped to 49.7 v.

Did the motor heat up during the test?

 

[PCeBiker]

I think it's possible that your controller is sending maximum power to the motor?
That could be why you've got the error code, and why your battery is draining so fast?

 

[Gionnirocket]

13ah is mid size for a battery and a 2v sag on a hill is normal.
What's the sag on a flat?
Why your charger is only putting out 54.1v is questionable... but it's only 0.5v and adds some safety. Probably just poor quality control at the factory and not unheard off.
Why the battery isn't reaching 54v is another question... As 1v is high for charging bounce. Do you know what the charger current output is?
Pic the spec tag on that if you can.
Depending on your charger you may need to leave it plugged in after the led turns green to let it finish charging. So many variables in charger and BMS function... it's hard to know for sure without testing all.
Some just aren't matched to each other's functions leaving some minor full charge issues.
Can't rule out the battery but I'm still thinking it's the motor.
Parts swapping is the easiest way to test so if you can get a hold of another battery to confirm.
How fast is the motor heating up?
Is it only overheating on hills?

 

[spokewrench]

That’s what I was wondering… If the battery was already on its way out and fried something in the motor. I’m not sure if that would be causal or coincidental.

Did you check battery terminal voltage? Naturally, charger voltage has to be a little higher than the battery it's charging. My charger reads 54.49 and charges the battery to about 54.05.

Another charger is too sophisticated to measure, but it charges to about 54.45.

If your charger won't get your battery to 54, maybe the charger is the problem. If it's at 54 or above right after you stop charging but is down after sitting an hour or so, that could be the BMS using passive balancing to bring up one or more low cells. I give it another hour on the charger and check again.

When I've had battery trouble cause motor shutoffs, I've seen the voltage on the display drop toward the shutoff level. Low voltage won't cause overheating. For more than 4 years, I've been recharging at 48 volts or so because it can get pretty sluggish with the battery lower. Less torque means the motor is getting less current.

I think @Slaphappygamer has the right idea, to check the phase lines with a multimeter. Overheating or corrosion in a connector could be the culprit. I don't know if hall sensors could cause overheating. I believe I checked them on one bike, out of curiosity.

 

[spokewrench]

I know from experience that the loss of a phase through poor contact will cause a 3-phase AC motor to overheat. I wanted to be sure that this was also true of magnet (brushless DC) motors.

Found it! Here are the 18 reasons a brushless DC motor may overheat.

Why do brushless DC motors get hot? What causes this? - Faradyi Motors

Causes of brushless DC motor overheating may include motor overload, low load power factor, too low speed, winding short circuit,

faradyi.com

In fact, "overheat" is mentioned only in (7), (8), (9), and (10). All four involve phase lines.
(8) is miswiring. I guess we can rule that out.
(7) is poor connection. (10) is disconnection. They could be easy to find and fix.
(9) is a short or grounding in a stator winding.

(5) says undervoltage can make a motor "prone to heat under rated load." That confused me at first because I know from experience that as the battery voltage goes down, so does throttle response. The key is "under rated load." A motor won't spin as fast with less voltage. To get the same power, you need a bigger pulley, requiring more torque, which requires more current, which produces more heat. It would be like climbing a hill with a mid drive motor in a higher gear.

 

[harryS]

motor feels very hot

I think this is a bad thing. The TSDZ2 is (poorly) designed with lots of air between the actual motor and outer case. Some guys fill the space with heat transfer material, like copper scrubbing pads. If it feels hot, then the insides are scorched.

I guess I would write it off as being cooked if it now happens on flat ground. Take a look and a smell. If you pull off the pedal and main lock nut on the left side, the side cover is removeable if the four screws that hold it haven;t corroded.

 

[spokewrench]

Uh-oh... I guess getting cooked would result in (9), a short or grounding in a stator winding.

 

[harryS]

The motor really is quite small. Electrify-Bike says it's 450W max, and recommends 10 A as a max. Otherwise they burn up, Meanwhile, Electrify-bike suspended sales of the TSDZ2B with OSF firmware because of reliabiity problems. I betcha users were going 18-20A.

TSDZ2 Inside Motor Core

TSDZ2 Inside Motor Core - replacement inside motor core for Tonsheng TSDZ2 and TSDZ2b motors. If run continuously above 450 watts, the TSDZ2 will overheat and - Electrify Bike

www.electrifybike.com

With mine using OSF firmware, , I've never seen more than 12A in battery peak current. Our average current is probably 3 amps. I'll have to rig the wattmeter up and see what I get on our hill.

 

[Sasquatch260]

Hey guys. I probably won’t be able to tear my motor apart till tomorrow but I just noticed something when I was moving my bicycle that could be significant.

When I tried to coast it backwards just to move it, it doesn’t move freely - the motor engages, there is tension and it growls. I wish there was a way to attach a video so I could show you what I mean. But when I push it forward it moves freely and the motor does not engage. When I lift the back wheel and pedal it, it moves freely in the motor does not engage. But when I coast it backwards it engages the motor and is hard to push.

Note, this is all with the battery off and just moving the bike. (I don’t remember it ever doing this before.)

 

[spokewrench]

I'm familiar with that with hub motors. If the motor is in good shape, it can escape notice. I may have had my first e-bike a year before I noticed. I don't get it pushing forward because the motor clutch doesn't engage. I think your motor would work the same way.

If yours is bad enough that you know it wasn't like that before, I guess your motor is damaged. I believe @harryS said they don't cost much to replace.

 

[Gionnirocket]

Hey guys. I probably won’t be able to tear my motor apart till tomorrow but I just noticed something when I was moving my bicycle that could be significant.

When I tried to coast it backwards just to move it, it doesn’t move freely - the motor engages, there is tension and it growls. I wish there was a way to attach a video so I could show you what I mean. But when I push it forward it moves freely and the motor does not engage. When I lift the back wheel and pedal it, it moves freely in the motor does not engage. But when I coast it backwards it engages the motor and is hard to push.

Note, this is all with the battery off and just moving the bike. (I don’t remember it ever doing this before.)

I believe that the motor gears engaging when pushed backwards is normal.
Not familiar with your specific motor but my Bafang Ultra mid_drive spins the pedals when rolled backwards. No real noise though.
Not when rolled forward.
@PedalUma... You're the TSD' afficionado... What ye' say?

 

[Slaphappygamer]

When I tried to coast it backwards just to move it, it doesn’t move freely - the motor engages, there is tension and it growls. I wish there was a way to attach a video so I could show you what I mean. But when I push it forward it moves freely and the motor does not engage. When I lift the back wheel and pedal it, it moves freely in the motor does not engage. But when I coast it backwards it engages the motor and is hard to push.

This is normal. I have 3 PEV. A dual direct drive scooter that acts like this. A RadRunner+, it had a rear Bafang hub does this as well as my bike. My bike has a rear Shengyi hub motor.