# Motorcycle battery Motobatt MB3U 12V 3.8Ah 50A AGM ![Motorcycle battery Motobatt MB3U 12V 3.8Ah 50A AGM](https://baterias.com/901-home_default/battery-motobatt-mb3u-38ah.jpg) > Motobatt MB3U motorcycle battery 12V 3.8Ah 50A AGM. QUADFLEX range. Dimensions 98×56×110 mm. Verified OEM cross-references and exact fit for your bike. **Category:** [Motorcycle Batteries](https://baterias.com/gb/motorcycle-batteries) → [MOTOBATT](https://baterias.com/gb/motobatt) - **Canonical URL**: https://baterias.com/gb/battery-motobatt-mb3u-38ah - **Language**: en-GB - **Brand**: MOTOBATT - **Reference**: BCOM-MOTOBATT-MB3U - **MPN**: MB3U - **Price**: 369,70 € - **Stock**: Out of stock ## Technical specifications | Feature | Value | |---|---| | Brand | MOTOBATT | | Reference | MB3 U | | Model | MOTOBATT QUADFLEX | | Voltage (V) | 12 V | | Largo | 98 mm | | Ancho | 56 mm | | Alto | 110 mm | | Peso | 1.34 kg | | Tecnología | Quadflex | | Cold cranking amps (EN) | 50 A | | Capacity (C20) | 3.8 | | Capacity (C10) | 3 8 Ah (c10) | ## Quick description **Motobatt MB3U 12V 3Ah 50A** is a sealed motorcycle battery ready to fit, with the JIS reference your mechanic recognises at a glance. Vibration-resistant, keeps voltage during the winter off-season and cranks first time when you take it out for a ride. ### Why this motorcycle battery? - **Same JIS reference** as your bike's original — fits first time - **Sealed and ready to use** no acid handling, no refills - **Survives winter storage** holds charge through long off-season 🔌 Voltage 12 V ⚡ Capacity 3 Ah C10 🔋 Cold cranking 50 A EN-1 📏 Dimensions 98×56×110 mm ⚙️ Technology AGM Quadflex ⚖️ Weight 1,34 kg 🏷️ Model MOTOBATT QUADFLEX #️⃣ Mfr. reference MB3U ## Description ## Motorcycle battery Motobatt MB3U Quadflex 3.8Ah 50A 12V 12*V* Voltage 3.8*Ah* Capacity 50*A* Cold cranking 1.34*kg* Weight The **Motobatt MB3U motorcycle battery** is rated at **12 V**, **3.8 Ah** and **50 A** of cold cranking current (EN) from the **Quadflex** range, and is designed for motorcycles, scooters, quads and personal watercraft. Measuring 98 × 56 × 110 mm, it is the direct replacement for motorcycles fitted from the factory with a 3.8 Ah battery of this format. - Holds its charge through winter storage. - Compact and lightweight format. - AGM: faster recharging and better cycle resistance than a conventional battery. - Sealed and ready to fit, no acid handling. ### Dimensions, polarity and mounting It has external dimensions of 98 × 56 × 110 mm and weighs 1.34 kg. Checking the three dimensions and the terminal position before buying avoids the most common mistake when replacing a battery. ### What the Motobatt MB3U is for Designed for motorcycles, scooters, quads and personal watercraft, the Motobatt MB3U replaces the original battery of bikes that use this code or format. Check the position of the positive terminal before ordering. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 1.34 kg. ### The Motobatt MB3U: Quadflex range and AGM technology Within the Motobatt catalogue, the **Quadflex** series groups the references designed for this use. The MB3U is the 3.8 Ah model of that family, with the same performance as its siblings in other sizes. AGM (Absorbent Glass Mat) technology seals the electrolyte in glass microfibre. The result is a maintenance-free battery that is highly vibration-resistant and able to withstand deep discharges that would ruin a classic lead-acid battery. ### Why choose Motobatt batteries Motobatt is the motorcycle battery specialist with Quadflex technology: four terminals that let you connect the battery in any position and a sealed AGM construction ready to fit. We guarantee that every Motobatt arrives new, charged and with the manufacturer's full warranty. ### Manufacturer's warranty The Motobatt MB3U comes with the **manufacturer's official warranty**. The warranty does not cover discharge through prolonged inactivity: if the bike stands for months, use a trickle charger. ### Usage and maintenance tips Check the resting voltage before the season (above 12.6 V on a charged battery) and make sure the terminals are clean and tight. Avoid repeated cranking attempts on a cold bike for long: if it does not start on the third try, let the battery rest for a minute. ### Delivery times and returns Same-day dispatch from our warehouse for in-stock orders placed **before [[ks:cutoff]]**: 24-48 working hours in mainland Spain and Portugal, 3 to 5 days in the islands and the rest of Europe. Returns are accepted for **[[ks:return_days]] days** if the battery has not been used (free collection on the Iberian mainland). You will receive tracking by email. ## Frequently asked questions ### How do I fit the MB3U model in my motorcycle? In most motorcycles it fits in 15-30 minutes with a 10 mm wrench; if the battery is under the seat or in the boot the time can double. See the step-by-step guide on this page. Quick summary: 1) switch off the engine and remove the key; 2) locate the original battery (engine bay, boot or under seat); 3) disconnect the negative (−) terminal first, then the positive (+); 4) loosen the hold-down clamp and remove the old battery; 5) fit the new one in the same orientation — match the polarity shown on the product sheet; 6) connect the positive (+) first, then the negative (−). On motorcycles with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile. ### How long does the Motobatt MB3U battery last? Expected lifespan of the Motobatt MB3U is 4 to 7 years in regular use (depends on technology and climate). In cold regions it drops slightly due to cold-start stress; in very hot regions it also drops because of electrolyte evaporation. To extend its life: avoid deep discharges (headlights on with engine off), have the alternator checked yearly, and keep the battery clean and properly secured. ### What are the measurements of the MB3U model? Dimensions (length × width × height) are 98×56×110 mm — also written as 98x56x110 mm — following the European DIN standard. Always measure the space in your motorcycle before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals. ### Is the MB3U valid for my vehicle? Three options to confirm: 1) enter your number plate in the finder (DGT/DVLA/KBA auto-detect your model and engine); 2) check the "Compatible vehicles" tab on this page, where we list every vehicle verified by our technical team; 3) if you cannot find your model, message us on WhatsApp with brand, model, engine and year — we reply during business hours (Mon–Fri 10:00–13:30 and 16:40–18:00 (Spanish time, CET)). The MB3U typically fits a wide range of European vehicles thanks to its standard DIN case format. ### Which batteries are equivalent to the Motobatt MB3U? Directly interchangeable batteries (same dimensions, same polarity, same Ah and CCA) are the OEM equivalents from leading brands: Bosch, Tudor, Exide and, depending on the model, Banner or Yuasa. Exact equivalence depends on technology — an EFB cannot be replaced with a conventional battery in Start-Stop motorcycles. See the "Equivalents" section to view recommended options at the same performance level. ## Reviews - **Average rating**: 4.74 / 5 (9 reviews) ## Technical team (editorial authorship) The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team — over 25 years of experience validating automotive batteries. → https://baterias.com/gb/technical-team --- *baterias.com — Automotive batteries · 2026-10-01*