The Panasonic OEM battery (blue ring maintenance free) in my 2000 4Runner has been able to start right up without a hiccup for almost 8 years. I just checked the voltage yesterday when engine and all accessories were off: 12.56 v. I think it is still within spec.

I am so curious about how long it will last. I understand the normal battery life is 3-5 years. What you guys think if I keep it till it fails?

2000 4Runner 4WD SR5 V6 Auto 16x8 Chrome Wheel, 265/70/R16 BridgeStone Duelers A/T All Terran
2009 Toyota Sienna LE V6 FWD