Semi off grid boat, aspiring to fully off grid 
So I’m trying to charge a LFP on the cheap while waiting for the new XS software that allows bi-directional charging, or me to just win the lottery LOL 
Yeah, so it’s a shoestring budget operation and I’m trying to charge LFP from AGM (shore powered and alternator powered) with a VSR. I’m not trying to put the perfect charge in, but just to ‘throw some amps that way’ in Bulk, manually monitored, with a VSR, and let the MPPT do the fancy business of topping it up properly from solar.
My LFP just needs some extra amps as the solar is not enough to run the fridge and other onboard stuff, hence the VSR which can occasionally charge from an overnight marina stay, and (IF I can find a way to limit amps from alternator!) engine alternator power. Also I plan to leave the VSR connected to power the anchor lighting from the LFP, which overnight makes a significant drag on my AGM house battery, and eventually grinds it down less than 50% (not good). Would love to put an XS B2B but the boat needs about 100 repairs, every one high priority 
Trying to just squeeze a little more out of the resources I have, which basically means making the LFP more ‘resistant’ so as not to burn up my alternator. Now it is a 150Amp alternator. But still I’d like to find a way (hopefully something inline in the VSR+) which adds just enough resistance to make battery charging not kill the alternator. Hope this makes sense.