On 2019-07-17, Theo wrote:
>However it won't tell you if the power bank is getting low - eg if the power
>came back after an outage (so the power bank is near empty) and then goes
>out again.

It seems to me that the tool for this would be a small in-line power
bank: inputs (from mains or main battery bank or whatever) across a
medium chunky capacitor, with a signalling line on the outside
isolated from the cap, so that when the input voltage drops it can
send a shutdown and power the Pi off the capacitor for those few
seconds.

(Actual circuit design is left to someone who knows what they're doing.)

--- SoupGate-Win32 v1.05