Today I finally managed to finish the assembly of our own solar panel for charging the car battery. I bought a large, flexible solar panel made in China from a SWES (Swedish Expedition Society) member earlier in the summer, to be used for charging the car battery the days we’re not driving, since the fridge/cooler uses a fair amount of battery power. But it had some weird connectors, so the first thing I had to do was to try to figure out what they were called and try to buy a pair so I could build a cable to connect the panel to the battery. After some investigations I figured out they were called MC4, and that they are quite common for solar panels. Next step was to find cables and connectors. I ended up ordering the connectors from AliExpress, for $1.66 including shipping.
The next step was to find cables. I was told to get at least 6mm cables. They cost a small fortune wherever I looked, so I ended up ordering 2 x 5m cable (black+red) from AliExpress as well. Total cost $35. I found battery clamps at Kjell & Co for 19 SEK/piece.
Once I had received the products, I spent the better part of the day figuring out how to build the MC4 connectors. After a number of tries I got it right. I measured that the panel was giving at least 15-16V charging in the sun, which is great. I had also bought a regulator to avoid overcharging the battery.
When I started tinkering I quickly realized that the crappy battery clamps I bought at Kjell & Co