Hello, I've been building my own solar panel system and throughout this process I've accumulated a lot of questions. If anyone could help answer them I would greatly appreciate it! First I'll start off explaining what I have. A polycrystalline solar panel 17V 2.2A and a mono crystalline panel 4.8V 4A (read by multimeter) I connect them in parallel to produce 16.8V 6.2A. Each of them have a "6A axial type" diode connecting the positive line and the solar cells.(I read that you use them to stop power from returning into the solar panels) I've connected them to a Shunt (which reads 12.9V 1.96A coming from the solar panels) and charge controller using a little less than 50 Ft of 10 gauge stranded copper wires. The charge controller is connected to a 12V 35ah battery that's connected in parallel to a 12V 7ah battery. I have an inverter that I connect to the load of the charge controller. I use that to power lights or charge cell phones. So that's my basic setup. As for my questions, I apologize if they seem a bit random and the large amount of questions I have. -Why is the shunt displaying 12.9V 1.96A if my multimeter is reading 16.8V 6.2A? -I bought 10 monocrystalline solar cells (4.8w) and connected them using adhesive copper tape but they produce less than my (2.8w) mono solar panel I built. I had soldered the solar panels up until I discovered copper tape. So does copper tape hold less lots and amps? -When I tried to connect my 4.8 W monocrystalline solar panel to my regular setup in parallel, it seemed like it actually took away from the power everything was producing, I don't know why. -Are these diodes actually needed if I have a charge controller? -Are they just taking away from the power the solar panels produce? -I decided I wanted to try powering small devices somehow and I found DC to DC converters. But I have no idea how to control the volts and amps enough so that it won't damage the electronics. I'm trying to power things like a peltier and a small fan. Can anyone help me understand how I can use the power I get to power these electronics? That's all I'll ask for now... it would be easier if I could upload pictures from my iPad or phone but I couldn't figure out how. I apologize in advance for any information I am missing and thank you for reading all of it.