SmartThings v5 motion sensor battery level "Unknown" (but v4 works) — manually assign a quirk?

I have two SmartThings motion sensors, one v4 and one v5. I have added both via ZHA (Aeotec USB stick). They both function, except the v5 shows “Unknown” for the battery level. The v4 shows the battery fine, including voltage.

I note that the v4 has the quirk:
zhaquirks.smartthings.motionv4.SmartThingsMotionV4

The v5 sensor has no quirks. I wonder if v5 does not work because of the configuration otherwise found in that quirk. Is there a way to manually assign a quirk? I cannot actually find any references in the config directory.

Hi Zane, I have a number of the 2015 model but added one recently which reports as motionv5 but says it is unsupported , did you add the support yourself as per the instruction ?

zigbee2mqtt:warn 2020-04-07 15:05:25: Received message from unsupported device with Zigbee model ‘motionv5’
zigbee2mqtt:warn 2020-04-07 15:05:25: Please see: https://www.zigbee2mqtt.io/how_tos/how_to_support_new_devices.html.

Steve

I’m not using zigbee2mqtt. I just use the standard ZHA integration, and I see no warnings in my log. I believe this is a bug in zigpy.