I am careful with batteries. I have two banks of Trojan golf cart T-125's for the house. I can select either or both by switch. I have a group 24 marine starting battery. The main bank is charged by a Heart charger/inverter that puts out about 140 amps/hour as I recall and keeps the starting battery charged by an echo. Well, I had the boat hauled for a bottom job. I left the freezer on by mistake (duh) and the yard didn't turn it off after I asked. So, five days later at launch, the house batteries were dead (altho there was still ice and a cold beer). No big deal, since the starting battery is on an isolator. Click. OOPS! Nothing. Checked the starting battery at 11.5 volts. So, I plugged in the charger for an hour and a half. Still not enough juice to turn over (the echo charger only puts out about 10 amps/hour as I recall). So, why didn't the isolator shift over to the house bank which was about 70%? And why did the starting battery discharge to begin with? I was told by the Vessel Assist captain who gave me a jump that the isolators require some degree of charge before shifting and that I probably didn't have my house bank up far enough. Beats me. I'll have to read up on that. More interesting is the issue with the starting battery. Never a problem before. It was about five years old, so I have been watching it carefully. Good amps, always full of water. I shut the house batteries off from time to time and start the engine by the starting battery alone. Always starts fine. So, it's apparent to me that it was just plain weak and that it never got a 'real' test from me since it was always topped off. And, I rarely let the house get too low either. Point in all this is that I could just as well been in some isolated cove and had this happen. So, I will check the starting battery in the future by letting it sit for a week off the charger. I'm going to replace it with an Orbital AGM. Expensive, but durable. Just submitting this as a heads-up to others with the same set up. (PS to us Left Coast sailors: The VA Captain told me that with the aquisition of Vessel Assist by Boat US, there will be some changes. He said the shift will be to make VA more like towing insurance than the assist-club it is today. For example, jump starts will not be covered in the future, and there will be other limiting changes. So, look for notice of coverage changes when you get your next renewal or the one following. This is second hand, of course, so take it only for what that's worth. Rick D.
what I thought were cables from the echo charger---were not. It isn't hooked to the starting battery, thus the isolator (combiner). Good call, Derek. It got dark before I could trace the isolator wiring, but its on the list. Couple of other points: I think it's a good idea to dump the isolator and activate the echo charge, but I don't feel strongly about it. What would be great tho is to swap the on/off starter switch to a off/1/both/2 switch and handle the mixing between the house banks and starting manually. This is largely what Tom has done it would appear, but I have to look his comments over more carefully. BTW, I equalize the batteries twice a year. The recommended cycles are all over the landscape, but it works for me. With an AGM in the mix, I'll have to remember to disconnect it. Anyhow, thanks for the leads and thoughts. I'm just glad this happened at the dock and not out in the Channel Islands or Baja.