Thanks @Maastricht for help me answering the questions..
About power consumption for iPhone, another user found a solution remove the auto brightness and adjust it manually..
In any case the BV6000 is the best solution.. expensive, but less than a Garmin..
Thanks for the reply. Do you need a SIM card to operate BLEvo on a BV6000?
Any ideas on the iPhone crashing please? I lost half my ride data and didn’t want to turn the screen off to preserve battery because I lost confidence in the app being active, and wanted to see it was recording data.
Many thanks