Motobatt MB3U · Motorcycle battery 12V 3.8Ah 50A AGM
Specifications
| Brand | MOTOBATT |
|---|---|
| Part number | MB3U |
| Voltage (V) | 12 |
| Capacity (C20) | 3.8 |
| Capacity (C10) | 3 8Ah (c10) |
| Technology | Quadflex |
| Length | 98.00 mm |
| Width | 56.00 mm |
| Height | 110.00 mm |
€369.70
VAT included
4,74/5★★★★★9 reviewsVerified purchases
- ★★★★★Pedro Ferrer:
Gracias a vuestra ayuda pude instalar la batería
- ★★★★★Jose Sanz:
Me alegra que cumplen con los tiempos de envío
- ★★★★★Mariano Serrano:
Agradezco que me asesoraran de cómo instalar la batería que compré
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 referenceas your bike's original — fits first time
- Sealed and ready to useno acid handling, no refills
- Survives winter storageholds charge through long off-season
Voltage
12 V
Capacity
3 Ah
Cold cranking
50 A
Dimensions
98×56×110 mm
Technology
AGM Quadflex
Weight
1,34 kg
Model
MOTOBATT QUADFLEX
Mfr. reference
MB3U
Motorcycle battery Motobatt MB3U Quadflex 3.8Ah 50A 12V
12VVoltage
3.8AhCapacity
50ACold cranking
1.34kgWeight
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 6:00 pm: 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 14 days if the battery has not been used (free collection on the Iberian mainland). You will receive tracking by email.
BCOM-MOTOBATT-MB3U
Data sheet
- Brand
- MOTOBATT
- Reference
- MB3U
- Model
- MOTOBATT QUADFLEX
- Voltage (V)
- 12
- Length
- 98.00 mm
- Width
- 56.00 mm
- Height
- 110.00 mm
- Weight
- 1.34 Kgs
- Technology
- Quadflex
- Cold cranking amps (EN)
- 50A
- Capacity (C20)
- 3.8
- Capacity (C10)
- 3 8Ah (c10)
Specific References
- MPN
- MB3U
4,74/5
Verified purchasesLatest verified reviews
★★★★★Pedro Ferrer
22/07/2026Su ayuda fue valiosa
Gracias a vuestra ayuda pude instalar la batería
★★★★★Jose Sanz
29/01/2026Muy rápido
Me alegra que cumplen con los tiempos de envío
★★★★★Mariano Serrano
09/01/2026Me ayudaron paso a paso
Agradezco que me asesoraran de cómo instalar la batería que compré
★★★★★Jorge NuÑez
29/12/2025Buenos precios
No tenía ni idea de cómo instalar la batería en mi coche y me ayudaron de principio a fin. Muchas gracias
★★★★★Jose Ignacio Vidal
22/11/2025Gracias por su asesoramiento
Gracias a vuestra ayuda pude instalar la bateria
Recommended accessories
How to change the battery
Guide to replace your motorcycle battery in 10-15 minutes. Motorcycle batteries are light (2-5 kg) and usually need an 8 mm wrench.
Step 1. Prepare the vehicle
Park on a flat surface, switch off the engine and remove the key. Make sure all lights and electrical accessories are off. Wait 1-2 minutes before starting.
Step 2. Locate the battery compartment
On motorcycles it is usually under the seat, in the rear cowl or behind a side panel. Check the manual — access varies a lot between models.
Step 3. Disconnect the negative (−) terminal
Use the 10 mm wrench to loosen the negative cable nut (black, marked −) and remove the cable from the post. Move it aside so it cannot touch any bodywork.
Step 4. Disconnect the positive (+) terminal
Repeat with the positive cable (red, marked +). Important: never let a terminal touch metal of the car while the other is still connected.
Step 5. Remove the old battery
Loosen the hold-down clamp or the straps that secure it. Lift the battery carefully — typical weight 2-5 kg. Check the terminals are not corroded before fitting the new one.
Step 6. Install the new battery
Place the battery in the same orientation as the old one (positive terminal on the same side). Tighten the hold-down clamp firmly.
Step 7. Connect the cables
Connect the positive (+) terminal first, then the negative (−). Tighten the nuts with the wrench until each terminal does not move. Apply anti-spark grease if you have any.
Step 8. Verify the engine starts
Close the bonnet. Start the engine to confirm everything works. On cars with Start-Stop or a BMS, you may need to register the battery via OBD so the alternator applies the correct charging profile.
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.
The top-rated online battery store in Spain
-
Audited by Trustpilot, no filters, no edits. The top-rated battery store in Spain.
Trustpilot · verified, no filters
-
Official Varta distributor
Official Varta wholesale distributor. 100% genuine batteries, recently manufactured, best price and no middlemen.
World’s best-selling battery brand
-
+100,000 satisfied customers
More than 100,000 customers already trust baterias.com — and recommend us to their friends and family.
They trust us and recommend us
Choose trust, choose quality, choose baterias.com.