P30 failed after just a few months of use and ate a few batteries (battery cases were dented and cracked from overcharging) -- I tried a second battery after the first one died, hoping that my first The battery was old or defective, but the charger also destroyed the second battery. I have reported the issue to WindyNation, along with photos of the damaged batteries and voltage readings of the PV panel, battery and load. WindyNation quickly replaced the defective charge controller with an improved model (P30L) free of charge. So far the P30L has worked flawlessly.