In March 2001 I installed a new house bank of 4 Trojan T125 golf cart batteries. The total capacity was 480 a-h so I usually tried to not draw below 240 measured by the Link 10. The charger is a Xantrex TruCharge 20. We stay in the water year-round and we keep the charger on whenever at the dock. The engine sports a second 100 amp alternator that feeds only the house bank controlled by an external regulator. On several occasions I would draw the bank down beyond 240 a-h, once to about 320 when we were on a cruise and scheduled to move a day later so we didn't bother to run the engine to charge. Looking at the log I see I topped the batteries up 3-4 times / year. They were usually down about 1/3 of the way between the full indicator and the tops of the plates. Our daily demand in the summer is about 50-60 a-h/day, mostly for refrigeration. Winter is about twice that from running more lights and the Ardic heater. We don't work to hard at economization unless we are going to be anchored in one location for several days. A winter project is to replace all the interior lighting with LED which will help a bit.

They might have gone on a little longer if I hadn't forgotten to turn on the charger when we got back from a weekend cruise a couple of weeks ago. Over several days the refrigeration drew them down to 10.5 volts before it cut out. After that they wouldn't take a charge. The Link-10 showed about 4-5 amps and got a bit warm but they were goners. So yesterday I bought 4 new T105s for $145 each (the T125s were $68.00 in 2001). Funny thing is I don't recall the batteries being so heavy the last time I lugged them aboard. Time does march on a bit. I considered AGMs but choked on the price. I think the flooded cells still give the best bang for the buck. I don't mind topping them up from time to time.