you've probably done the due diligence...most battery packs are warranted for a minimum of 8 years and 100,000 miles. They don't require 20% of the products (transmissions, fuel lines, spark plugs, air filters, batteries, brake cylinders, Oil changes, oil filters, etc. that your gas engine needs and I've owned a lot of gas engines that need work before 8 years on mechanical parts associated with gas engines. But it's probably important that you stay in the past...GL2U