Ok, in the last couple years I managed to go from a bike, to a stable and it's preseting a hassle factor i hadn't thought would be a hassle.

Two bikes have the LiFePO batteries - by two different makers, Full Spectrum in my Monster, and 'Alien Motion' in a track 675 I just got. The sumo still has a lead battery, but at 5 years old it won't do much longer and will get replaced - and I was planning on Shorai for that as they have a pretty exact fitment.

So I'm trying to run down a tender type charger I can share among them. Each manufacturer has it's own - Shorai being the oddest as it uses a 5-pin set up. Alien motion just has gator clips (um ok...) and Full spectrum has some sort of pig tail you connect to the battery that comes with the charger, but doesn't publicly sell additional pig tails (that I can find). I thought this wouldn't be such a pain, but it seems it is

Battery Tender (brand) lists one other their site, but it's out of stock. And the only vendor I've found with it online list it out of stock too - or am I just ahead of their production curve and they haven't put it on shelves yet

So I'm just trying to find a set up for LiFePO batteries that will allow me to install pig-tails on each bike (hopefully SAE connections) and then share one tender type unit in rotation.

A regular battery charger will work, just not as well as dedicated chargers since LiFePO batteries will not fully charge without equalizer circuitry.  Smart chargers even less so since they go to float too early.  Assuming your track bikes don't have pesky draws like alarms on them they should also rarely if ever need charging.  Just make sure they don't go below 13.2 volts, as that makes them very unhappy.

I don't know about everyone else, but for me, one of the biggest draws of switching to a Ballistic battery, was that I wouldn't need to use a tender. And I haven't needed to use a tender, it's been great.

Panda, there is a thread in Advrider about these bateries.  One guy there named _cy_ who likes to tinker with these things has tested the Yuasa small smart charger (the cheap wallwart one) and found it had the best voltage match for the lipos and was cheap to boot.  Did not recomend the larger more $ Yuasa charger.  I'm using it on my Antigravity battery and seems fine.

The float voltage thing mentioned by _cy_ in the thread got me thinking and I tested my battery tender and my battery doc and the battery doc float voltage was better suited for my AGM battery than the BT.  So I moved the BT to a flooded lead acid and the doc to the AGM.