I don't remember you saying what type of battery it is but if it's an AGM or that kind of newer battery they have a very bad track record and lots of them fail after a year. I stick with the regular old fashion lead acid, and they don't let me down.
Strange, i read that they dont need charge controllers at such low wattage. I hardwired one of these into my car 5 years ago. Ive left it sit for months and it fires right up every time. Once i left it for 6 months and started right away like it had a full charge. I think its actually saved the battery from preventing sulfidation caused by low voltages. Im curious, did you measure the voltage on the batteries it killed? Maybe your panel doesnt have an internal diode and its draining them overnight? Edit, I looked up some reviews on yours, its killing some batteries overnight, I bet it doesnt have a diode to prevent drain overnight. Id put one in, they cost a few sence and the solar cells will last much longer and it will properly maintain your battery.
I don't remember you saying what type of battery it is but if it's an AGM or that kind of newer battery they have a very bad track record and lots of them fail after a year. I stick with the regular old fashion lead acid, and they don't let me down.
Strange, i read that they dont need charge controllers at such low wattage. I hardwired one of these into my car 5 years ago. Ive left it sit for months and it fires right up every time. Once i left it for 6 months and started right away like it had a full charge. I think its actually saved the battery from preventing sulfidation caused by low voltages. Im curious, did you measure the voltage on the batteries it killed? Maybe your panel doesnt have an internal diode and its draining them overnight? Edit, I looked up some reviews on yours, its killing some batteries overnight, I bet it doesnt have a diode to prevent drain overnight. Id put one in, they cost a few sence and the solar cells will last much longer and it will properly maintain your battery.