My old Diehard battery lasted a few months shy of 10 years. So when it came time to replace it, there was no doubt that I would replace it with another Diehard battery. I have always used Diehard batteries and I always will.
The Polar Vortex (otherwise known as a winter cold spell) zapped the battery which was just installed at the beginning of the summer to replace a 6yr old Duralast. Tried charging (my Die Hard portable jumper kit, showing 100% on digital readout, still would not start it), driving for a day and started fine, afterwards (that evening). 2 days later, morning; same thing, dead again. Don't care what type of deal/discount I can get on one of these batteries in the future, I'll PASS! This is ridiculous.
Shop charged an additional 19.95 for the battery installation from what I paid online. Otherwise everything else was fine.
I replaced my old die hard battery only because it's more than 5 years old but still good. 5 years is usually the recommended replacement time for batteries for optimum charge.
Last one I brought lasted 7 years with no problems