Motobatt MB51814 BMW Motorcycle Battery – 12V 20Ah 235 CCA AGM

The Motobatt MB51814 is a sealed AGM BMW motorcycle battery sized for the bikes that take the BMW 51814 or 51913 case: 12 volts, 20 amp-hours, and 235 cold cranking amps. It ships factory activated and charged, so there is no acid to fill and nothing to do but bolt it in and ride.

AGM means the acid is held in glass mat separators instead of sitting loose in the case. It stays sealed, it will not weep onto your paint or your garage floor, and it handles engine vibration better than a conventional flooded battery. Motobatt's four-terminal Quadflex layout gives you both polarity orientations on the same battery, so it fits bikes where the positive lead comes off either side, and you have a spare post pair for a heated grip or a charger pigtail instead of stacking three ring terminals on one bolt. Terminal bolts, caps, and the allen wrench are in the box.

The 235 CCA rating is above what most of these applications came with from the factory, and the 20Ah capacity is what lets the battery recover between cranks. That is the part that matters after a Northeast Ohio winter. A bike that sat from November to March asks a lot on the first start of the season, and a marginal battery fades after two attempts. Riders pulling bikes out for the Geauga County backroads around Chardon and Chesterland run into it every spring.

Replaces BMW 51814, 51913, and These Part Numbers

Drop-in replacement for the following part numbers. Bring the old battery in, or read us the number off the label, and we will confirm the fit before you buy.

• BMW 51814
• BMW 51913
• Yuasa YT19BL-BS
• Odyssey PC680
• WPS 491-1025

Before you order, measure. This is a full-size case at 7.2 inches long, 3.15 wide, and 6.69 tall, and battery trays are not forgiving about height once the seat goes back on. If your bike has been rewired or has a non-stock tray, check clearance first. And if you are replacing a PC680 that is doing standby or deep-cycle duty rather than starting an engine, this is a cranking battery and the wrong tool for that job. Call us and we will point you to the right chemistry.

Key Features of This BMW Motorcycle Battery

• 235 CCA and 20Ah in a factory-size case: more cranking power and more reserve than the OE battery in most of these applications
• Sealed AGM construction, so there is no acid to fill and no acid to spill on painted bodywork
• 99.99% pure lead plates with thicker grids and denser paste than the OE design
• Four-terminal Quadflex layout covers both polarity orientations and leaves posts open for accessories
• Ships factory activated and charged, ready to install out of the box
• Hardware included: two M6 terminals, four screws, four terminal caps, and a 4mm allen wrench

Specifications

Keep it on a lead-acid or AGM-mode maintainer over the winter, and do not put a lithium-mode charger on it. A stored battery that never sees a charger is the most common reason a good AGM comes back dead in the spring, and it is the easiest thing to prevent.

Local Pickup in Northeast Ohio

This one is on the shelf at our Willoughby shop. We stock powersport batteries for riders across Lake and Geauga counties, from Mentor and Eastlake out to Chardon and Chagrin Falls. Call ahead with your year, make, and model and we will have it tested, charged, and waiting at the counter.