My friend was letting me know his buddy was developing a new battery, that weighs 4.5 lbs.
here's the info from the website.
Voltphreaks 12 Volt car battery. This is compatible with all passenger cars and trucks. Replace your 12 volt lead-acid starter battery with this one and save 30 to 40 pounds! Current state of the art in battery technology (safe nano-phosphate lithium).
Standard lead-acids last 3 to 5 years before needing replacement. Voltphreak's LiFePO4 battery will last 5 to 10 years. Besides saving weight, you will have less voltage drop under load, for stronger cranks. Plus it's less affected by cold weather than a lead-acid battery. We've cold cranked a BMW M3 10+ times without any issues, then left the headlights on and radio blaring for 15 minutes, and then cranked again, and the car cranked same as before!
This battery does not have the thermal runaway issues of standard lithium batteries, and is much safer. In fact, it's way safer than the lead-acid battery currently in your car, and better for the environment too! Check out more information on nanophosphate lithium technology.
Because this battery is a lot smaller than standard lead-acids, you can screw or bolt mount using the mounting flanges. We used double-sided emblem tape to mount the battery in our personal car.
Our warranty and return policy
Refunds are allowed for ANY reason, doesn't crank your car, you don't like how it looks, you just wanted to try the battery out, etc. You just can't abuse the battery (running it over, putting it in a fire, etc). So feel safe in purchasing this battery, we are so sure you will like it that we don't expect many returns!