Starting a couple of months ago, I had to start adding water to the batteries in my EGT150 after every 3 or 4 charges. Sometimes one battery, sometimes 4 batteries, sometimes all 6. The pack is 6 year old set of Sam's Club Energizers and has been recharged by a Minnkota 315D for 5 of the 6 years. The tractor performance does not seem to suffer but the total charging time is less than when the pack was new.
Is this common for a battery pack reaching the end of its operational life cycle? The charger is currently applying 41.6v 5 hours into the charging cycle. The pack voltage was at 38v when the charge started.