inputs.text: works - took chance device based product description installation device appears work less advertised hard determine exactly since voltage set points not actually specified controller appears shipped set flooded leadacid batteries instructions suggest possible set device different battery chehemistry gel agm instructions not however actually tell appears may missing text tiny fanfolded instruction sheet although couple computerstyle jumpers couple bare wire jumpers pc board open controller tech support absolutely no help trial error discovery not practical set points shipped seehem ok robust battery measured bulk charge voltage 148 volts cutting back float value 137 would hesitate use device unattended location typical light duty rv type deep cycle battery however mine sits older 4dd since bulk voltage value held 2 hours warm tehemperatures could result excessive electrolyte loss relatively short time andor warped plates due heating plan use controller part upgrade 12v solar powered lighting systehem shed including adding panels adding 1500 watt inverter run tools changing flooded battery agm end left flooded battery place 4dd goes eol toss instapark controller buy name brand adjustable set points new agm battery controller seehems reasonably well constructed price ruining even one battery would completely negate cost difference instapark say xantrex morningstar unit installed numerous othersystehems work flawlessly