To help with battery insertion/removal I picked up on a suggestion in some user forum to apply candle wax on the track and the tray. It reduces friction without attracting any grit or other substance that a liquid would.

In the middle of my last RadMission ride the PAS level lights on my LED display suddenly started flashing and then within a minute or so I completely lost power.  Rad customer support pointed me to a helpful online RadMission Communication Error Troubleshooting Guide (which might suggest that the problem is not that unusual). I resolved the problem, which was in the LED display connector which had somehow gotten unscrewed and detached. The guide, however, has as a first step a disconnect/reconnect of the battery tray connector. Since that is a more difficult connector to get at, I suggest that anyone with a similar issue first check the LED display connector, which may save you some time and effort.

Has anyone had experience using one of the portable power banks/chargers available out there (see link below for one) to charge a Rad battery on the road? At 1.5 lbs it would be easy to carry along, but if it takes a very long time to charge it wouldn't be very useful.

https://www.hsn.com/products/mophie-powerstation-go-max-power-bank-and-car-jump-star/9842547

A 3-D printed thumb throttle adapter: https://www.ebay.com/itm/223592231970