Or search for "aili 18650 powerbank".
This is the kind that satisfies the requirements. I haven't tested it for EMI with my FT-817 yet. Using it as an extra power for laptops.
It can charge from a 19V laptop power adapter with 5.5x2.1mm barrel tip and can output 5/6/9/12/15/19V selectable by mechanical switches on its 5.5x2.1mm socket. Has a USB-A output for the phone as well.
The best part for field operation is that you can replace 18650 cells with ones pre-charged at home, so essentially "unlimited" capacity.
You need to understand what you are doing, like closely matching the 2 strings of 3 cells each when installing. Instruction manual is not included, but can be found online.
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73, Mike AF7KR
