You have a generator
and lifepo4 batteries
? Want to bulk-charge fast?
Everyone knows the price
of 60Amp marine charger
What to do if you need 100Amp? or 150Amp? or 300Amp?
Answer from RC Groups - Dell server power supply! 1500W of industrial quality - $40-100 on Ebay.
With a little tuning - voltage can be regulated very precisely btw 12v-14.2v
A simple high quality 12Volt 100Amp Power Supply- Part1 - Page 37 - RC Groups