I carry a jump pack which helps with warding off the feathered feeling. Also could help a fellow motorist in need.
I like reading about the 12v's that last a long time, thanks to those for posting. I plan on keeping mine until it gives strong signals that it's time. I'm on 3.5 years.
Sorry if this is a dumb question, what is a deep discharge? Is that letting the battery drain down from leaving a light one, for example?
The battery was replaced. The car was having trouble coming on. I've had to boot it up 4-5 times and the displays in the car would do some weird things like not turn on or change my MPH to KM/H. But if you're asking how the battery was disposed of I do not know. The mechanic took it away and put a new one in. Since then my MPG has improved immensely.