My Powervamp battery recently gave up after a number of year's of faithful service. It expired at the most inconvenient time, so I was scratching my head what to do.
I then remembered that buried somewhere in the garage was another Powervamp battery - I bought it some years ago, and didn't fit it (another story).
In desperation I put it on charge and then fitted it to the car - that was 4 months ago and it is going strong.
I found the invoice the other day - 2011*yikes*
So sat on a shelf neglected for nearly 9 years, and yet still serviceable. I'm impressed.