After 10 years of my ownership (undetermined number with PO), I needed to replace the battery in my '93 500E. With Costco as my base ($177 Group 49 (H8) Interstate AGM), I checked all of the usual suspects and bought one from my local Advance A/P store, which was selling an Autocraft (made by Johnson Controls) H8 AGM Platinum battery for $160 ($200 list minus $40 [20% online purchase discount without having to sign up for anything; 25% off if you signed up for their email/rewards program]). They would have installed the battery for free, but I declined, preferring to do that myself and on my own schedule.