Bosch SX 400wh with AXS power adaptor range effect?

[SuperJ]

I have a Devinci ETroy Lite, that came with the AXS S1000 derailleur. Instead of a battery it has a power cable running to the bosch battery.
It appears the bike sees it as a headlight. (In the phone app it shows the headlight as on, and I don't' seem to be able to turn it off. )
I'm not really concerned about the power draw of the derailleur, but am concerned if the Bosch system is going to reserve capacity for the headlight. I've read about this in other threads on older Bosch bikes.
Will having the headlight enabled on my SX 400wh bike reduce the available range? If so I might consider using batteries in the derailleur.
Unfortunately you can't disable the headlight with the app, I would have to get the bike shop to do it.

 

[SuperJ]

Here are some photos.

 

[Hawk13]

I really wouldn't worry about it using the main battery - how much do you really think it is going to use?

My Trek runs the same way - says it has approx. 300 shifts in reserve when the battery is showing as empty. Which I guess could give me an extra metre of drive

 

[Shark58]

Will having the headlight enabled on my SX 400wh bike reduce the available range? If so I might consider using batteries in the derailleur.

Yes it will reduce the available range, but not by much. Depending on what the manufacturer defined in the diagnostic system the reduction can range from 1.5% to 9%. See full explanation below.

The SX motor has only three electric connectors. Two of those are used on any bike for the main battery and the display/controller. The third is called multi purpose port (MPP) and can be used to attach one or more additional devices like front and rear lights, an external speed sensor, ABS ...

In your case the manufacturer uses that port to connect the SRAM derailleur. To make it work the MPP port has to be activated. It will show up in the Bosch diagnostic system as light port - activated, always on and with a specific value for the output capacity in Watts. Always on makes sense, because if you could turn the "light" off your derailleur would stop working.

The value for the "light" capacity is used to internally calculate the power reserve for a minimum of two hours after the motor quits working due to low battery. This will make sure that any light, an ABS system or a derailleur will continue to work for two more hours. This calculated power reserve is not available for the motor and therefore reduces range.

Worst case scenario is the manufacturer set the output value to the maximum of 18 watts and thereby reduced the battery capacity for the motor by approximately 36 Wh (18 W times two hours) or 9% of the 400 Wh main battery. The last time I have seen a Bosch diagnostic system the lowest value one could set was 3 watts, which is more than enough for the SRAM system. This will reserve 6 Wh, a reduction of only 1.5% from the main battery.

I would recommend seeing a Bosch service dealer and check that the light capacity is set to the minimum value.

In case you want to remove the cable powering your derailleur, it is not enough to simply turn the lights off. This will still keep the reserve. You would need to deactivate the MPP port to get the reserved capacity back.

 

[Deleted member 9676]

I have a Devinci ETroy Lite, that came with the AXS S1000 derailleur. Instead of a battery it has a power cable running to the bosch battery.
It appears the bike sees it as a headlight. (In the phone app it shows the headlight as on, and I don't' seem to be able to turn it off. )
I'm not really concerned about the power draw of the derailleur, but am concerned if the Bosch system is going to reserve capacity for the headlight. I've read about this in other threads on older Bosch bikes.
Will having the headlight enabled on my SX 400wh bike reduce the available range? If so I might consider using batteries in the derailleur.
Unfortunately you can't disable the headlight with the app, I would have to get the bike shop to do it.

I can help you remotely disable anything you want.

 

[pinoymamba]

How many extra ports are there to plug in? I have a light port that was activated that I removed. Would I need to connect the AXS plug into that port? The dealer told me that the system conserves a bit of battery for that light and since I've disconnected, it's battery "loss".

 

[Deleted member 9676]

How many extra ports are there to plug in? I have a light port that was activated that I removed. Would I need to connect the AXS plug into that port? The dealer told me that the system conserves a bit of battery for that light and since I've disconnected, it's battery "loss".

On the SX motor you have only one extra plug. (Battery, display, power port)

 

[SuperJ]

Thanks for the info, I'll verify with the shop what the power setting is at. I'm relieved there are different settings rather than just 18w. Just didn't want to lose km's of range on a already small battery.