steelsmithj
commented
7 years ago 12 hours seems like a really long time for the super cap to keep the board powered. Was your board in direct sunlight during most of the time? There are solar panels on the canaries that feed to the super cap. However, I have only needed to leave the batteries out for 10-15 minutes before I can get a complete restart.
Also you mention having old/new boards. On the underside of the new boards is there a white label with a version number (mix between characters and numbers) that ends with the 'E' character? If so, have you ever had a problem with not being able to flash the boards at all?
Occasionally after battery removal, canaries enter an unresponsive state in which no user action (battery insertion, RST short- or long-press, ribbon cable connection, etc.) can activate the board. This has been most frequently observed following keyboard interrupt of the mosquitto message broker immediately prior to battery removal. The only way a canary has been observed to regain function is after it has been left unpowered for 12 hours; boards from an old batch require 60 hours. We suspect a capacitor is supplying sufficient charge to hold something in working memory that prevents the board from engaging its normal startup routine.