AGM to LiFePO4 conversion gotchas

Swapping AGM for lithium (LiFePO4) is not drop-in despite marketing. Real gotchas: (1) Alternator regulation. AGM tolerates a stock alternator's dumb bulk-charge; lithium can pull maximum current continuously and cook a stock alternator in an hour. Solution: external smart regulator (Wakespeed WS500, Balmar MC-618, or Victron equivalent) with a battery temperature sensor and alternator temperature sensor, plus lithium-specific charge profile. (2) Charge sources plural. All chargers on the boat must have a lithium profile, solar controller, inverter/charger, engine alternator, shore charger. Missing one and you'll either undercharge (lithium happy at 90 percent) or overcharge (BMS trips, blackout). (3) Low-voltage load disconnect. Lithium BMS will hard-disconnect at low voltage with no warning, killing electronics mid-passage. Add a Battery Protect (Victron) or similar to loads to shut them down 0.5V above the BMS trip point. (4) ABYC E-13 compliance: DC main disconnect, over-current protection sized for lithium's higher short-circuit current, and no lithium in engine start service unless the BMS is spec'd for cranking. Budget US$8-15K for a proper 400-800 Ah conversion done right.