I recently rplaced all my boats wiring and electrical system i went with a bep marine 717100a with digital vsr's for my battery switches. The boat is a 1986 grady white offshore 24 with 1987 twin 150 yamaha 2 strokes. I replaced both start batteries ainstalled a new house battery. When the boat isn't being used the 40 amp 3 bank onboard charger charges and maintians the batteries. All electrical loads come off the house battery. The engine batteries are just for cranking the engines. While cruising this weekend for about 45 mins at 4500 rpm's both engine volt gauges were showing 14 volts for 30 minutes but the vsr's never started to charge the house battery. I opened the battery switch compartment door the red led never turned on. I triple checked my wiring and it's all correct. The only wires i don't have hooked up are the 4 18 gauge wires 2 black and 2 orange for the optional charging led light. I know the older 2 strokes Don't have a really high "alternator" output. Usually my engines start in 6 seconds. So it's not like i'm running them down alot.