The Small Case line of Antigravity batteries are our battery of choice for custom projects. They offer a significant weight advantage along with compact size and ability to be oriented in any direction allowing for very discreet placement on a bike. The LiFEPO4 cells provide a considerable amount of amperage for their comparative size and when sitting maintain their charge longer than traditional lead acid batteries.
Before We Go On...
If you're not already familiar with LiFEPO4 batteries when you buy an Antigravity Battery the first thing you should do upon receiving it is READ THE MANUAL. The very next thing you should to do is REGISTER YOUR WARRANTY. There is a window of time in for you to do this, if you procrastinate it may be a costly mistake.
What size battery do I need? Or in other words, what is the smallest battery I can get away with?
I've condensed the manufacturers recommendations into a single reference chart.
We've pushed these boundaries on our own custom builds and found that with the right circumstances you may be able get away with a battery smaller than what is recommended below. If you're running LED lights and the bike is getting plenty of ride time to charge up the battery you might be fine with the next size down but you need to consider a number of factors like your displacement, power requirements and ride style then use your own discretion.
A precautionary measure
We recommend that you install a quick connect harness and keep your bike on a float charger when not in use for a length of time. If you have an m.unit installed they have a very low draw in the milliamp range that over time will pull your battery down, additionally this will protect you battery in the event of a parasitic drain.
Further reference information from Antigravity