My Optima battery gradually grew weaker and weaker so it now cant start the car after sitting over night without being on a battery tender. My car dealer checked out the car and determined the battery needs replacement. Still under the 3 year warranty, I contacted Bigtime Battery and they had me ship the battery to them. My shipping cost was $62. Three weeks later they told me the battery works fine. Yes, it can start the car but only if I keep the battery on a charger. They returned this useless battery to me. I have now bought an Interstate battery with no problems. They are NOT an authorized Optima dealer.