Ninebot S1 Battery Fuse

[love.unicycle]

My Ninebot S1 broke down last month.

I was siting in park bench, and leaned S1 beside my leg. I didn't turn it off. It somehow tried to go under chair and lost power.

The power button stops to response since then.

Last night, I figured out  battery fuse had blown. Here is the BMS I found from internet:

http://content.invisioncic.com/r254450/monthly_2017_11/board1.jpg.90acf227b54bd71ecc8d739270ea3a08.jpg

Those two on left-top corner of board, having Z letter on top, are fuse.

I replaced them with 65V and 15AMP one.

https://www.digikey.ca/product-detail/en/littelfuse-inc/2410SFV15.0FM-065-2/2410SFV15.0FM-065-2CT-ND/2766075

I could start S1, but blown again soon after.

Do any of you know what kind of fuze it is?

 

[GMOne]

9 hours ago, love.unicycle said:

My Ninebot S1 broke down last month.

I was siting in park bench, and leaned S1 beside my leg. I didn't turn it off. It somehow tried to go under chair and lost power.

The power button stops to response since then.

Last night, I figured out  battery fuse had blown. Here is the BMS I found from internet:

http://content.invisioncic.com/r254450/monthly_2017_11/board1.jpg.90acf227b54bd71ecc8d739270ea3a08.jpg

Those two on left-top corner of board, having Z letter on top, are fuse.

I replaced them with 65V and 15AMP one.

https://www.digikey.ca/product-detail/en/littelfuse-inc/2410SFV15.0FM-065-2/2410SFV15.0FM-065-2CT-ND/2766075

I could start S1, but blown again soon after.

Do any of you know what kind of fuze it is?

 

IMHO I think that there are other problems due to the main board (and/or the motor).

Can you ride it a little bit?

Any other symptom? Take a look to your main board, or better please take some pictures of it...

Edited September 26, 2018 by GMOne

[love.unicycle]

I had looked to main board. There is not sign of problem.

Don't know how to check motor.

How do we know whether a motor is good or not?

 

[Keith]

6 hours ago, love.unicycle said:

I had looked to main board. There is not sign of problem.

Don't know how to check motor.

How do we know whether a motor is good or not?

To start with, the motor is a max 1000W motor at nominally 54V which is peaks of 18.5Amps which it can easily hit, or exceed, when standing still as that is when the back e.m.f. from the motor is zero and the only current limiter is the tiny resistance of the motor windings. So a 15 Amp fuse is going to blow easily - that may be all the problem you have?

Secondly, those fuses, on the BMS, are last ditch attempts to prevent a fire on chronic overload. I.e. they are not meant to be replaceable so should only fail under way beyond maximum load. My guess, and it is purely a guess as I don’t have the specifications is that those fuses should be at least 30 amp and possibly more than double that.

Your description of the fault suggests you did overload it heavily (tilt it to get it to drive hard and prevent it moving) so the first problem is that it is possible something else failed before the BMS fuse, most likely one or more of the output FET’s on the main board. They tend to fail short circuit so would explain the BMS fuse going as well.

Motor windings could also have failed or heated enough to short coils through burnt insulation which would then probably kill FET’s as well. This is less likely though. The only real test you can easily do, short of powering the motor with a new board or using an impedance meter is to test across every combination of two of the three motor power wires. Every combination should have the same resistance, but this is such a low figure you may not be able to tell a good coil from a short. 

If you can fit a fuse that is high enough not to blow, failed FET’s, if they have occurred, should manifest as the wheel being to stiff to turn when powered up but free when powered off.

[love.unicycle]

On 9/27/2018 at 4:34 AM, Keith said:

To start with, the motor is a max 1000W motor at nominally 54V which is peaks of 18.5Amps which it can easily hit, or exceed, when standing still as that is when the back e.m.f. from the motor is zero and the only current limiter is the tiny resistance of the motor windings. So a 15 Amp fuse is going to blow easily - that may be all the problem you have?

Secondly, those fuses, on the BMS, are last ditch attempts to prevent a fire on chronic overload. I.e. they are not meant to be replaceable so should only fail under way beyond maximum load. My guess, and it is purely a guess as I don’t have the specifications is that those fuses should be at least 30 amp and possibly more than double that.

Your description of the fault suggests you did overload it heavily (tilt it to get it to drive hard and prevent it moving) so the first problem is that it is possible something else failed before the BMS fuse, most likely one or more of the output FET’s on the main board. They tend to fail short circuit so would explain the BMS fuse going as well.

Motor windings could also have failed or heated enough to short coils through burnt insulation which would then probably kill FET’s as well. This is less likely though. The only real test you can easily do, short of powering the motor with a new board or using an impedance meter is to test across every combination of two of the three motor power wires. Every combination should have the same resistance, but this is such a low figure you may not be able to tell a good coil from a short. 

If you can fit a fuse that is high enough not to blow, failed FET’s, if they have occurred, should manifest as the wheel being to stiff to turn when powered up but free when powered off.

A wonderful notes about how to find out the root cause of problem.

Likely I need to get a new mother board for my S1.

 

[Tiny]

Same here

[I Love Prince]

I had exactly the same prob with my xiaomi m365 it was a fuse in the control box so I replaced control box which cost around £30 and is as good as new!