BikeMaster Trugel Battery MG9-4B1 - 780543

The BikeMaster TruGel Battery MG9-4B1 (Part #780543) is a gel electrolyte powersports battery engineered for motorcycles, scooters, and small-displacement bikes that demand reliable starting power and long service life. Unlike conventional wet-cell batteries that require maintenance and are prone to spills, this BikeMaster TruGel unit delivers a sealed, leak-proof design with a lifespan claimed to be twice that of a comparable wet battery — making it one of the most popular BikeMaster TruGel battery upgrades for vintage and modern small-displacement riders alike.

Key Features & Benefits

• Gel Electrolyte Technology: The gel electrolyte construction eliminates free liquid acid inside the case, making this battery leak-proof and spill-proof — a major safety advantage over traditional wet-cell batteries, especially on older bikes without a dedicated battery box drain.
• Twice the Lifespan of a Wet Battery: BikeMaster rates this TruGel battery at approximately double the service life of a standard wet battery, meaning fewer replacements and better long-term value for riders who keep their machines for years.
• Superior Vibration & Impact Resistance: Gel batteries are inherently more resistant to the vibration and mechanical shock that damage traditional wet batteries — a genuine advantage on older motorcycles, scramblers, and small-displacement bikes that lack sophisticated vibration isolation.
• Will Not Sulfate: Unlike wet batteries that sulfate when left discharged for extended periods, this TruGel battery resists the sulfation process that permanently reduces battery capacity — a key benefit for seasonal riders and collector bikes that sit for months at a time.
• Longer Shelf & Storage Life: The gel chemistry provides a longer storage life both on the shelf and while installed in the bike, though BikeMaster does recommend charging during prolonged storage periods to maintain optimal capacity.
• Wide Temperature Performance: This battery performs better at both lower and higher ambient temperatures compared to a standard wet battery — useful for riders in colder climates where cold-cranking demands are highest.
• Any-Angle Installation: Because there is no free electrolyte liquid, the MG9-4B1 can be installed at virtually any angle, giving you flexibility on custom builds or bikes with unconventional battery tray orientations.
• Two-Year Manufacturer's Warranty: BikeMaster backs the TruGel MG9-4B1 with a two-year manufacturer's warranty, providing meaningful peace of mind for a powersports battery at this price point.

Specifications

• Part Number: 780543 (SKU: BKM780543)
• Battery Model: MG9-4B1
• Battery Type: Gel Electrolyte Powersports Battery
• Cold Cranking Amps (CCA): 150 CCA
• Dimensions: 135 mm L × 75 mm W × 139 mm H (approximately 5.31" × 2.95" × 5.47")
• UPC: 887337003801
• Warranty: Two-year manufacturer's warranty

Fitment

The BikeMaster TruGel MG9-4B1 battery fits a wide range of small-displacement motorcycles and scooters. Always verify fitment against your specific year, make, model, and submodel before ordering. Confirmed fitment applications include:

• 2010 Aprilia RS 125 (Base)
• 2009–2011 Aprilia Scarabeo 100 (Base)
• 2008–2011 Aprilia Sportcity 125 (Base)
• 2009–2011 Aprilia Sportcity 50 (Base)
• 2012–2013 Aprilia SR 50 (Base)
• 1965 Honda CB160 (Base)
• 1978–1979 Honda CB400TI Hawk I (Base)
• 1966 Honda CL160 Scrambler (Base)
• 1968–1972 Honda CL175 Scrambler (Base)
• 1981–1982 Honda CM200T Twinstar (Base)
• 1982–1983 Honda CM250C Custom (Base)
• 1988–1990 Honda VTR250 Interceptor (Base)
• 1966–1971 Kawasaki A1 Samurai (Base)
• 1967–1971 Kawasaki A7 Avenger (Base)
• 2001–2009 Kawasaki BN125 Eliminator (Base)
• 1969–1972 Kawasaki H1 Mach III (Base)
• 1982 KTM 500 K4 (Base)

This is a partial fitment list. If your specific year/make/model does not appear above, contact the ThreePiece.us fitment team before ordering to confirm compatibility. Fitment is determined by physical battery size and terminal configuration — always measure your existing battery or battery tray if in doubt.

What's in the Box

This listing includes the BikeMaster TruGel MG9-4B1 gel battery (Part #780543) as a single unit. No separate acid pack or activation is required — the gel electrolyte is factory-sealed. Note that BikeMaster recommends an initial charge before first use and periodic charging during long-term storage.

Why Buy from ThreePiece.us

• Free Shipping: Every order ships free — no minimum purchase required.
• Affirm Financing: Split your purchase into manageable payments through Affirm, so you can get the parts you need today.
• Expert Fitment Support: Not sure this is the right battery for your bike? ThreePiece.us has served over 10,000 customers and offers personalized fitment help — call the team at 813-535-5801 or use the on-page fitment contact form.
• Regularly Stocked: The MG9-4B1 is a regularly stocked product at ThreePiece.us, so you're not waiting on a special-order lead time for this battery.

Frequently Asked Questions

Q: Does this battery come ready to install, or does it need to be filled with acid first?
A: The BikeMaster TruGel MG9-4B1 is a sealed gel electrolyte battery — there is no separate acid filling required. The electrolyte is factory-sealed inside the case. BikeMaster does recommend an initial charge before first installation and periodic charging if the battery will be stored for an extended period.

Q: What are the physical dimensions of the MG9-4B1?
A: According to the product listing, the MG9-4B1 measures 135 mm long × 75 mm wide × 139 mm tall (approximately 5.31" × 2.95" × 5.47"). Always compare these measurements to your bike's battery tray dimensions before ordering.

Q: How does a gel battery compare to a standard wet-cell battery for a motorcycle that sits for months?
A: Gel batteries like the BikeMaster TruGel line are specifically noted for longer shelf and storage life compared to wet batteries. They also resist sulfation — a common failure mode for wet batteries left in a discharged or low state of charge during off-season storage. BikeMaster still recommends charging during prolonged storage, but the gel chemistry provides meaningful advantages for seasonal riders.

Q: My bike isn't on the fitment list above — can this battery still fit?
A: The fitment list above is partial. The best approach is to compare the MG9-4B1's dimensions (135 mm L × 75 mm W × 139 mm H, 150 CCA) to your current battery's specs, or contact the ThreePiece.us team at 813-535-5801 for fitment assistance before ordering.