After testing a number of options for mobile-powering a Pi we now can offer this cost-effective and powerful battery pack. We tested it with all Pi boards. It worked fine with all boards. We did occasionally get under-power icon for 3B+ BUT the board ran fine regardless how much load we were putting on the CPU!
We also have a bigger version of this power bank.
Type-C USB port, dual USB output;
High capacity of 10400 mAh;
LED light and LED charging status;
Multiple safety protection system to ensure devices safety;
Battery Tupe：Li-ion Battery
Input：Micro USB:2.1A Type-C:5V/3A Total max: 5V/3.4A
Output：USB-A1:5V/1A USB-A2:5V/2.4A Type-C:5V/3A
Raspberry Pi will run for hours without grid power. You can turn it into days or even weeks with Sleepy Pi power management board.