Yuasa Motorbike battery 51913-DC 12V 19Ah (conventional / lead-acid)

The Yuasa 51913 (often labelled "DC" for Dry Charged) is a classic lead-acid battery specially developed for older motorcycles with high energy requirements. With a full capacity of 19 Ah (10h), it is the traditional power plant for many BMW motorcycles (Boxer and K series) of the 70s, 80s and 90s. As a conventional battery ("wet battery"), it offers proven technology, robustness and an excellent price-performance ratio for youngtimers and classic bikes.

Highlights at a glance

• The BMW classic: The standard size for countless BMW models (e.g. R80, R100, K75, K100), perfectly matching the narrow, tall battery boxes of these machines.
• High capacity (19 Ah): Offers enormous energy reserves, which are particularly important in older starters and alternators for reliable starting and a stable on-board system.
• Dry Charged (dry pre-charged): The battery is delivered dry and can be stored indefinitely. It is only activated when acid is poured in (usually included in the scope of delivery).
• YuMicron technology: Yuasa's special separator technique reduces internal resistance and provides up to 30% more starting power than conventional standard batteries.
• Maintainable: Thanks to the accessible closure plugs, the acid level can be checked and, if necessary, corrected with distilled water – ideal for lovers of classic maintenance.
• Robust construction: The hard-wearing case protects against vibrations and corrosion, which is particularly important for the strong vibrations of old boxer engines.

The power plant for BMW "rubber cows" & bricks

The 51913 is almost legendary among BMW riders. It fits the BMW R series (R45, R65, R80, R100 GS/RT/RS) as well as the BMW K series (K75, K100, K1100). Due to its special dimensions (very narrow, but long and high), it is often difficult to find modern alternatives that fit into the original holder without tinkering. This Yuasa battery guarantees original appearance and fit.
 

Features

FAQs about Yuasa 51913

Is acid included?

If marked "DC" (Dry Charged) or via mail order, the battery is usually delivered with a separate acid pack (check legislation: end customers are often not allowed to receive loose acid packs, so the retailer often pre-fills it). Check the offer exactly. If it arrives dry: add acid, leave to stand for 30 min, charge, done.

Do I need to top up this battery with water?

Yes. This is a conventional battery with vent. You should check the fluid level 1-2 times a year (or more in high temperatures/high mileage). If it's below the "Lower Level" mark, please top up with distilled water (no acid!).

Where is the vent pipe connected?

The battery has a small opening on the side (usually right). The transparent vent hose must be connected there. This directs gases and any acid droplets that may escape downwards onto the road. Make sure that the hose is not kinked, otherwise the battery can burst.

Is there a maintenance-free alternative?

Yes, GEL or AGM batteries are now available for this format (often under the name 51913-GEL or similar). These are completely sealed and leak-proof, but are often a little more expensive and sometimes have a slightly different capacity. For lovers of originality, the classic Yuasa 51913 remains the first choice.