Originally Posted by 250kts
ran my hand over the top of the battery and was surprised to find the top very distorted, the other is still completely flat.
1. I am assuming that this is bad news, 2. What is the likely cause, 3. Can anyone recommend where a replacement my be purchased at reasonable cost.
Cause: severe overcharging of the battery.
The Optima is the best -by a mile- marine battery available, but can only withstand so much abuse. Any other battery would have given up much earlier, would have leaked acid or gel into your boat, or even could have exploded.
Before you do anything: find the cause of overcharging. Or the next battery will follow also ...