Thunderchild
New Member
I bought a couple of panels on ebay that are 20 watts and listed as 12 volts but they are actually 17.5, now I'm aware that i will need more than 12 volts to charge lead-acid batteries but surely 17.5 is a lot. do charging controllers work with switch mode cicuitry ? so that the voltage can be dropped and the amperage increaased a little ? or am I best just using a proper smps to do it ?