Solar Charge Controller / USB Power Regulator

[olsenn1]

I have two folding solar chargers:
        1. Instapark Mercury 10 -- 10 Watt dedicated USB charger
        2. Powerfilm F12-750 -- 12 Watt 15.4V charger

When I connect the Mercury 10 to my electronic load at CV (5V) I get 1.0 Amp of current (5W) and this is the most I can reliably push out of this. However, when I connect my Powerfilm charger via a switching buck converter (8-24V to 5V USB) to the same e-load under the same lighting conditions, I get 0.5 Amp (2.5W) at CV 5V. This is in line with what my devices charge at when I plug them into this USB port. However, I can switch the e-load to CC 1 Amp and get the same 1A@5V output of this solar panel this way.

Obviously my solar panel is capable of outputting more power than it is. Does anyone know what I could do to fix this? Would a MPPT charge controller do the trick (or is this just for ensuring against overcharge of lead-acid batteries)?

Thanks!

[paulclark]

Hey there,

If under the same lighting conditions (No shadows on solar cells), one possibility is that the switching buck converter makes the solar efficiency down. My suggestion is to have a solar controller to make it suitable for your e-load.

This Hovall solar phone charger is good for all USB devices and laptops.
https://www.hovall.com/product/solar-phone-charger/

Paul