Question for experts

[bcroe]

If the PC says 19V what the loaded voltage/current needs to be ? It
seems that what I measured on an open circuit drops down so dramaticaly that there is no
enough volts to trigger charging. Arthur

That is the nature of PV panels. Higher open circuit voltage, expect that to drop 20% when the
panel is delivering rated power. Also remember, a 4A panel will only be capable of that current
under the most intense ideal sun. Apparently your load pulls the voltage down and then shuts
down; a scope could show this happening. Probably a hard 19.4V supply would work fine, but
must be capable of the current demand. This is not the way to make use of PV panels; rather
you want to take what you can get to charge the batteries. Bruce Roe

[sadarahu]

Thanks bro,...for some reason the sales person from SUNKINGDOM (where I bought the first panel) is telling me that 24V would not work. I'm not sure if I could order 24V instead of 18 because in that case I might need to use extra regulator which I already have but for trips without my marine battery I would rather leave it home. Also replacing the regulator (which is about the size/weight of PC) makes not much difference. I could of course try to use lighter adapter then Inverter to put 120V on my tablet but still it requires PS. At this moment my main concern is if 24V would eventually do the job for tablet. The downside is that there are almost no panels in the stores to test. All you can find is for phones and most of them would not even work for newer power hungry phones. All panels over 20W can be only found on-line which makes really hard to make a decision and figure out what would work or not. I have already lost $25 returning one panel to the seller.

Arthur