Troubleshooting a Shimano STEPS EP8

[Convaruuq]

Hi!

I’m troubleshooting a Shimano STEPS EP8 setup that won’t power on and I’m hoping someone here might have insight.

The system consists of an EP8 motor, BT-E8010 504Wh battery, SC-E5000 display, EW-SS301 speed sensor, and SD300 wiring. Everything is connected as it should be, but there is no response from the system at all, the display stays completely off and the motor does not react. The battery appears normal, showing full charge on the LEDs and charging correctly with the charger.

I disconnected the main power lead going into the motor and measured voltage at the connector, but I’m getting 0V. The battery is mounted in a standard Shimano external mount, and although the locking part was previously damaged, the electrical contact section seems intact. I’m trying to understand whether the battery should output voltage directly at the mount or if it only activates when the system initializes, and whether a fault in the mount or internal wiring could cause this behavior. Are there known cases where the battery appears fine but doesn’t deliver power, and what would be the best way to narrow down whether the issue is the battery, the mount, or something else in the system?

Thank you!

 

[steve_sordy]

I may be answering the wrong question here, but as you have had a load of views without response, I'll have a go.

My on/off switch is on the top tube. Sometimes, when the bike is left for a longer time than usual without riding or charging, the battery in the switch can go flat. The Shimano battery can be started by pushing an Allen key through a hole in the frame (see pic). One firm push should do it, remember not to be pressing on the pedals at the time. The hole is covered with a rubber bung. In my case and many others, this process starts the bike and the switch is then charged.

In the pic below, I have the battery held alongside the frame, so that you can see the location of the bung. This bike is an EP8-powered Merida e-One Sixty, but even if your bike is not a Merida, the principle will be the same. Don't lose the bung!

Edit: Please add your location, the nearest town/city/county/state will do.

 

[Vision_Tim]

Not sure if this is helpful, but I had something similar happen to my with my EP6 system. Turns out a kinked wire connected to the display was actually separated and would only make a connection when it was held at the kink. I replaced the wire and no more issues.

If you find this is your problem, you can cut and splice these because there are only two wires in there. Just use some shrink tubing after joining them and you should be good-to-go.

 

[Convaruuq]

I may be answering the wrong question here, but as you have had a load of views without response, I'll have a go.

My on/off switch is on the top tube. Sometimes, when the bike is left for a longer time than usual without riding or charging, the battery in the switch can go flat. The Shimano battery can be started by pushing an Allen key through a hole in the frame (see pic). One firm push should do it, remember not to be pressing on the pedals at the time. The hole is covered with a rubber bung. In my case and many others, this process starts the bike and the switch is then charged.

In the pic below, I have the battery held alongside the frame, so that you can see the location of the bung. This bike is an EP8-powered Merida e-One Sixty, but even if your bike is not a Merida, the principle will be the same. Don't lose the bung!
View attachment 180789

Edit: Please add your location, the nearest town/city/county/state will do.

Thanks, appreciate the suggestion!

This is an external BT-E8010 battery setup, so I don’t think it uses the internal wake-up switch, but I’ll double check if there’s any hidden reset or power input on the frame.

The main thing I’m seeing is 0V at the motor input, so I’m currently focusing on whether the battery mount or wiring is actually delivering power.

 

[Convaruuq]

Thanks, that’s helpful!

I agree wiring could definitely be part of it. In my case I’m actually getting 0V at the motor power input, so I suspect the issue might be further upstream (battery mount or power cable rather than the E-Tube display wiring).

Appreciate the input!

Not sure if this is helpful, but I had something similar happen to my with my EP6 system. Turns out a kinked wire connected to the display was actually separated and would only make a connection when it was held at the kink. I replaced the wire and no more issues.

If you find this is your problem, you can cut and splice these because there are only two wires in there. Just use some shrink tubing after joining them and you should be good-to-go.