alt Hacker NewsSpare battery: remove empty battery, switch battery, you are back to 100% Powerbank: mess with cables, keep phone plugged until it's charged and wait
If there is a market for spare batteries, there might be a market for external battery chargers as well > swap battery in the morning instead of charging, place empty battery on charger, repeat the next day
Spare batteries are a nightmare to handle. Far too easy to bend or have something short-circuit the pads, and you have to shut down and restart your phone.
However, what is needed desperately is the ability to quickly change a degraded battery.