Lithium motorcycle batteries

Swapping a lead battery for lithium iron phosphate can remove a surprising amount of weight from a motorcycle, often several kilograms on larger bikes. Cranking stays strong, voltage holds steady and self-discharge is very low.

Compare models by equivalent lead-acid reference, CCA, dimensions and terminal layout, and make sure your charger supports lithium.

What changes with lithium

LiFePO4 cells deliver high current with little voltage drop, so the starter turns briskly even with a modest capacity rating. For that reason lithium batteries are often labelled with a lead-acid equivalent in Ah (PBEq) as well as their real capacity. Compare the equivalent figure with your original battery, and check CCA too.

Lithium cases are frequently smaller than the battery they replace. Many models include foam spacers so they sit firmly in the compartment; make sure terminals are positioned so cables reach without strain.

Is your motorcycle compatible?

• Charging system: the regulator should keep voltage roughly between 13.8 and 14.6 V. A faulty regulator that overcharges will damage any battery, but lithium is less forgiving.
• Charger: use one with a lithium/LiFePO4 profile. Desulphation or recovery modes designed for lead can harm lithium cells. See our battery chargers.
• Cold starts: in freezing temperatures a lithium battery may need a few seconds of load (headlight on) to warm up before cranking.

Who benefits most

Track and sports riders gain from the weight saving. Bikes that spend long periods parked benefit from the very low self-discharge. Adventure riders appreciate the stable voltage for heated grips and navigation devices. Riders on tight budgets or with old charging systems may prefer a sealed AGM, available in the general motorcycle batteries section. The FULBAT lithium range covers many common fitments.

Frequently asked questions

Can lithium motorcycle batteries be completely discharged?

Deep discharge below the cell limit can disable them. Some models include protection electronics, but avoid leaving lights or accessories on when parked.

Do I have to change anything on the bike?

Normally not, if the charging system works correctly. Verify the regulator output with a multimeter before fitting, with the engine at around 3,000 rpm. Readings well above 14.8 V point to a regulator problem that should be fixed first.