LFM vs LFX - What's the difference?

SHORAI Lithium-Iron (LiFePO4) Powersports battery w/BMS, 7.0Ah 13.2V, "A" polarity, Case Type 6, Length 5.83" Width 3.23" Height 5.51". Shorai Batteries require a charging system output of 13.1 Volts or higher at idle, and must not exceed 15.2 volts at maximum output.

Case size #6, 148mm length, 82mm width, 140mm height

Specifications and Dimensions

Part +	Voltage Pb Eq	Polarity	W/HR	A/HR	CCA (A)	Weight (KG)	Weight (LBS)
LFM21A6-BS12	12V		92.4	7.0	315	1.38	3.03