Spent ages reading the various forums in the US on Motorcycle Battery Choices, the net of this seems to be as follows:
a) Lithium-ion Batteries (LiFePO4 or LFP) - Good for starting, but v-bad if left to dis-charge fully, avoid if left with alarms etc that discharge over time
b) AGM (Advanced Glass Matt) Sealed Gel battery's - Good for colder temperatures, will tolerate less frequent use
c) Traditional Lead Acid - Sealed or Not - Require topping up, with battery water, issues managing Acid, spills, but cost effective, reliable
a) LFP = Are light, small, high performance but critically require suitable chargers and built in regulation - over charging (or fully discharging) NOT good
also seem fraught for bikes used infrequently, or that discharge via leakage etc, e.g. better for moderns used regularly or race bikes (which are
typically dis-connected when not in use)
b) AGM - Seem to be good compromise, sustain performance better in colder weather and with less frequent use, more expensive than traditional LA.
c) Lead Acid - A good choice for budget constrained, assuming still a quality brand, appropriate rating, right charging system / regime etc
Refer: https://www.victronenergy.com/blog/2015/03/30/batteries-lithium-ion-vs-agm/
Wrong management, incorrect charging systems (Lead Acid or AGM with LFP Batteries) can cause fires, be careful, I spoke to a local Custom / Classic specialist where a Lithium-ion battery built into the casing of a classic 1960's BMW had exploded, due to an incorrect trickle charging type / system.
Anyone had different advice, it seems a bit of nightmare, tomorrow I'll ring Richard at Slaters to get his PoV, as the original UK Laverda importer