Test/read the output from my solar setup?

The voltage is good, or so I assume since my devices are charging.

What I’d like to know it the actual mA output as it charges.

All google could find me are reviews of panels.

Edit: can it be detrimental to charge a power bank too slowly?

when using solar as a charge source it is good to have lots of voltage headroom. as the voltage can drop alot under load.

there is no problem charging slowly, but if you are exposing the battery cells to heat for a long duration, that can take a toll.

Thanks for letting me know about the slow charge.

It seems what I am looking for is a Charge Doctor. Just ordered one on ebay.