When you returned to your boat and found the acrid smell, likely your batteries were low on electrolyte and probably quite hot...it's quite possible some plates warped causing internal shorts and final death and some addtional heat. At this point they were effectively "gone" or close to dead. Under such circumstances, even with plain old worn out batteries, monitors will often show full charge... incorrectly. All they know is that at some voltage little current flows. It looks just like a fully charged battery. But when disconnected from the charging source, battery voltage drops rapidly and little power is available. I'm assuming your boat is gas powered or electronically controlled diesel as a mechanicallly controlled diesel will run with no battery power. An advantage of old diesel twechnology!! Apparently, as you noted, power was lost when you reduced speed...likely because alternator output was close to zero and dead batteries could not keep the ignition hot. Even if you were charging multiple banks via a combiner, it would have disconnected when voltage dropped and your dead start batteries would still have killed your engine(s). Usually, nearly dead batteries look more like an open than a short so charging virtually stops.,.few ions for anything ....current drops to a low level...hence I'm not sure your inverter/charger would have been putting out high current...only the modest level equalization current.... Likely with new batteries everything will be ok. Your experience is one situation which points out the potential value of separate battery banks for twin screw boats....hopefully banks purchased at different times don't die simultaneously... Glad you made it thru this without serious consequences. It's another reminder how careful we all need to be when boating. Rob Brueckner Hatteras YF

> When you returned to your boat and found the acrid smell, likely your > batteries were low on electrolyte and probably quite hot...it's quite possible This is a clear demonstration that boats with dead/dying battery banks are little more than derelicts. I have had more than my share of boats with just such problems. A few suggestions. 1. If you have any question about the state of your batteries, make sure the generator is running and charging all batteries any time you are near any obstacles. If the only thing that is keeping your voltage up is the engine alternators then they should be supplemented with the gen set. 2. It is good practice to follow rule 1 when crossing bars. 3. It is a good rule to implement rule 1 during night operations if you have any question about your voltage. The most common reason why the rules above are not followed, is the mistaken notion that one is saving fuel and wear and tear on the gen set. Remember what "The Joker" said to Lt. Ekhard, "think about the future". If fuel is what you are worried about slow down by 1/4 knot. Mike _____________________________________ Capt. Mike Maurice Beaverton Oregon(Near Portland)