Help! Yamaha System randomly turning off

[dean142]

Hello, I have just purchased my first E-Bike and taken it out. Was cycling up a small hill and the bike randomly cut off without me touching anything. Turned it back on after I noticed it. Carried on cycling and worked for 3m and it done it again. So I thought this can't be right. During my bike ride it turned off about 6 times during 20m. Its a yamaha system with a PW-ST motor and 1.7 display. The dealer is looking into it but they never heard of this issue before. No error codes are displayed and I have tried re inserting the battery to see if its a contact issue and its not. Anyone have any suggestions!

Thanks!

 

[soundwave]

if it is new with warranty id take it back to the dealer to sort out as could be anything esp if no error codes are displayed.

 

[dean142]

if it is new with warranty id take it back to the dealer to sort out as could be anything esp if no error codes are displayed.

Ye they are taking it tomorrow. Just seeing if anyone had any ideas as it could just be a simple fix!

 

[soundwave]

could be just a loose connection but i think you have to drop the motor from the bike to check the wiring harness.

if they did a pdi check b4 they sold it they would of found that problem pretty fast but most just dont bother and are box sellers these days.

 

[Bobajob]

You could just ask for your money back. If you wait for it to be fixed you’ll be with no bike.

 

[reeldeel]

Did they ever locate the issue? Having exactly the same issue with a brand-new Babboe Curve Mountain, which also features the Yamaha PW-ST mid motor - the electronics turn off completely after 20 minutes. The same problem occurs on the replacement bike the vendor gave me, albeit less often, so I’m scratching my head whether this is a problem with a whole batch of batteries?

 

[saneagle]

If there's no error code, it would indicate that the battery switched off or it lost connection. You just have to find out why or how.

 

[reeldeel]

If there's no error code, it would indicate that the battery switched off or it lost connection. You just have to find out why or how.

Yep, no error code. Thanks for the pointer!

 

[chris_n]

Or the display unit may not be seated correctly.

 

[saneagle]

and Yamahas have a battery in the LCD. It might be worth checking whether it's gone flat:

 

[soundwave]

check the charger voltage as had some faulty ones that was over 42v and was bricking the batts.

 

[reeldeel]

check the charger voltage as had some faulty ones that was over 42v and was bricking the batts.

Wow, didn’t think of that… Yamaha? Were the batteries still doing something or did they flat out die?

 

[soundwave]

they was going out of balance and was getting the bms bricked tho i thought they fixed this but it could be something else.

cant really do much if you have warranty

 

[reeldeel]

they was going out of balance and was getting the bms bricked tho i thought they fixed this but it could be something else.

cant really do much if you have warranty

Thanks, I’ll measure the voltage on the charger!

 

[chris_n]

Thanks, I’ll measure the voltage on the charger!

Whatever you do be very careful where you stick your multimeter leads, according to the German forum you can kill your battery if you get it wrong. You would probably also not find the charging voltage without a battery connected as the charger won't switch on until communications are established between the battery and the charger.

 

[reeldeel]

Whatever you do be very careful where you stick your multimeter leads, according to the German forum you can kill your battery if you get it wrong. You would probably also not find the charging voltage without a battery connected as the charger won't switch on until communications are established between the battery and the charger.

Aw thanks, that’s beyond my skill set then Thanks for the safety advice!

 

[saneagle]

Whatever you do be very careful where you stick your multimeter leads, according to the German forum you can kill your battery if you get it wrong. You would probably also not find the charging voltage without a battery connected as the charger won't switch on until communications are established between the battery and the charger.

Yup. You can't measure the charger's voltage - the same with your battery. You need to take it to the dealer to check, or do some surgery.

 

[chris_n]

I have done some surgery and run a 385Wh extender battery. Only connect when battery voltage is v close (straight off the chargers is within 0.1v) and Yamaha battery is switched on.