I have a limited electrical knowledge and have a few questions.
I have an Allpowers Foldable Solar panel, which has two USB outputs, and one 18 volt output. I understand that, in full sun at 18V, the panel would be producing 4.44 amps.
I was considering purchasing a 20000mah 'jump start' battery and want to be able to recharge it with my solar panel. I believe this is a lithium battery, although they don't specifically say on their site: https://www.suaoki.com/u10.html
The charging input for this battery specifies the charging input as 15V, 1A. The customer support folks for the battery felt that my solar panel would damage the unit if I tried to charge directly from my panel.
My questions are:
1) Is the problem the excessive voltage in full sun, or, would the problem be the excessive amps, or both?
2) If the problem would be the voltage, would using a buck converter to lower the voltage (to 15V) make it safe to charge through the 15V, 1A charging plug on the battery?
3) Is the excessive amperage a problem, or would the battery draw only the 1 amp that it needs?
4) While I have seen a number of inexpensive converters that would limit the output voltage from the solar panel, I have not found one that would convert 18V, 4.44A to 15V, 1A. Does this type of voltage and amperage limiting converter exist, or is is simply that the extra amps don't matter in this case?
Thanks for any information you can provide on this.