Hi! I connected up Renogy 50A dual input DC - DC battery charger with MPPT and the service battery light keeps slow flashing red. Why is this? I have two Vmax 125ah batteries. Multimeter read of batteries are 13v. I set everything up with the following system... https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html.