Some stuff... --- Dont use a 24 volt battery! --- A healthy bike charging system should run around 14 volts, the 15.5 is listed as a max number. Got a voltmeter? test it. --- The lithium Iron Phosphate batterys are kinda different animal and a comparison to an AGM is like the apples/oranges thing. A load test wont get it. -- As vf1000ride said, the batterys are sensitive to the bikes charging and the overall condition of bikes charging needs to be good. Otherwise, not good. - Same again no trickle charger. -- These should be fully charged out the gate. -- LiFePO4 batteries dont like the cold for start up. -- Nice thing is disconnected they will keep 99% of the charge for over a year. Just pull it in the house for the winter. No charger. -- Going on 4 years on mine and over time, it has gone from 14v at the end of a ride and then about a month to drop to 13v to the same 14v at an end of a ride to about a week to 13v. So, its a quirky dude. Stay within its performance window and youll be fine. Dont wanna screw with that? Get the AGM and trickle charge in winters. Mine http://www.motydesign.com/