That "Cheap Charge Controller" will act to fully charge an AGM battery better than a four hundred dollar multi-stage genius charger. It is set to 14.40 volts AFTER your solar panels DO NOT fully recharge the Lifeline and it does something no other machine will do
IT STAYS AT 14.40 VOLTS until you see .5% amperage.
You need a heart rending surplus of solar panels to do the same thing. Like FIFTY AMPERES WORTH. To buy the surplus time during the day to allow amperage to slump.
Do as you wish -- I tried to help. Lifeline is going to echo my words. Adios.