Interstate website's FAQ sections says the following:

  • Conventional deep-cycle batteries do require regular watering to keep them working properly. Check water levels every 4-6 weeks.
  • Undercharging: This will cause the battery to be sulfated. Fully charge batteries after use.

Who charges their battery after each use? Who checks the water level every month? I thought all batteries these days were maintenance free. Wrong. Mine was less than 1 year old and it died, probably because it sat idle in the hot summer without being charged.

Lesson learned: if you want a truly maintenance free battery, it must be the AGM type. You don't have to add water and it can go much longer without a charge.

Walmart Platinum AGM comes with a 5 year full replacement coverage (not prorated) and it includes installation. Even the Optima warranties aren't that good.