The Optima Redtops are great for retaining voltage. If you put an external charger on it be sure it has a AGM mode. Also note the CCA of the Optima are often rated low and will put out that power long past the usual voltage cutoff/fallout (<9V even). I worked on military projects using them in UPS and developing chargers for them, and they are really fantastic. I'm still running OEM in my car for now since I haven't had an issue even with my upgraded stereo.

I don't know about in the US but in Canada the best prices on Optima's were Walmart, hands down.

 

I would like to know what the brand for the OEM battery is. I was surprised when my local dealership told me they use AC Delco. I would like to know if this is approved?

 

I think there are only a handful of manufacturers and batteries are rebranded by distributors and retailers.