Motobatt MBTX20U 12V 21Ah 310A 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.

With 21 Ah at 12 V and 310 A of cold cranking current (EN), the Motobatt YTX20BS with AGM technology replaces the original battery of motorcycles, scooters, quads and personal watercraft. It replaces the original battery without adaptation in motorcycles with a 175 × 87 × 155 mm format: same 21 Ah capacity.
The Motobatt YTX20BS is a common replacement in motorcycles, scooters, quads and personal watercraft. If your bike spends the winter standing, a trickle charger stops it reaching spring flat. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 6.50 kg.
The Quadflex is the Motobatt range the YTX20BS belongs to: it shares the same construction and quality criteria with the rest of the series, and varies in capacity and format to suit each vehicle.
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.
The Motobatt YTX20BS is made in the 175 × 87 × 155 mm format and weighs 6.50 kg. For a direct replacement, the current battery tray must accept these dimensions and the same terminal layout; otherwise adapters will be needed or the hold-down will change.
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. At baterias.com we work directly with the manufacturer or its official distributor: real stock, brand-new product and official warranty.
Charge with a charger that has an AGM mode: it limits the voltage and protects the glass-fibre separators. Check the resting voltage before the season (above 12.6 V on a charged battery) and make sure the terminals are clean and tight.
The Motobatt YTX20BS 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.
Orders placed before 6:00 pm with the battery in stock ship the same day. Delivery in mainland Spain and Portugal takes 24-48 working hours; for the Balearic and Canary Islands and the rest of the European Union allow 3 to 5 working days. You have 14 days to return an unused battery; in mainland Spain and Portugal collection is free. We email you the tracking number as soon as the parcel ships.
Data sheet
Specific References
The Motobatt MBTX20U is interchangeable with these equivalent references: MBTX20UHD (Motobatt), 518902026 (Varta).
| Product | Specifications | Technology | Price |
|---|---|---|---|
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12V 21Ah 310A | Quadflex | €149.20 |
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12V 21Ah 310A | Quadflex | €149.20 |
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12V 18Ah 250A | AGM | €112.60 |
Equivalences verified by our technical team: same dimensions, polarity, capacity and CCA. Official manufacturer warranty on every option.
Guide to replace your motorcycle battery in 10-15 minutes. Motorcycle batteries are light (2-5 kg) and usually need an 8 mm wrench.
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.
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.
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.
Repeat with the positive cable (red, marked +). Important: never let a terminal touch metal of the car while the other is still connected.
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.
Place the battery in the same orientation as the old one (positive terminal on the same side). Tighten the hold-down clamp firmly.
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.
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.
Three ways: 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 for the YB16CLB; 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)).
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.
This motorcycle battery includes 6 months of official manufacturer warranty against manufacturing defects. On motorcycles, jet skis and quads, the standard warranty is shorter because long inactive periods accelerate natural sulfation. Practical tip: connect a trickle charger if the bike will be idle for more than 2 weeks — it dramatically extends battery life.
In mainland Spain and Portugal it arrives in 24 h if you order before 6:00 pm and the battery is in stock — it leaves the same day and arrives the next business day. Afternoon or weekend orders ship the next business day. For Balearics, Canaries and other EU destinations, allow 2-5 days. Shipping cost is calculated in the cart based on destination and service (standard, express, cash on delivery). Tracking number is sent by email + SMS as soon as the parcel ships.
Yes. You have 14 days from delivery to return it. In mainland Spain and Portugal returns are FREE — we cover the return shipping cost via prepaid label. In other EU countries the return shipping cost is the customer's. It must arrive in its original packaging with no signs of installation. If it was defective, the warranty covers replacement even after the 14-day period.
The current price at baterias.com is €149.20 (VAT included; €123.31 excl. VAT), updated every 24 hours. The applicable VAT may vary with the destination country and is confirmed in the cart. Shipping cost is calculated in the cart based on destination and chosen service (standard, express, cash on delivery).
At baterias.com — authorised distributor with real stock, Express 24h delivery in mainland Spain and Portugal if you order before 6:00 pm, and full manufacturer warranty. Shipping cost is calculated in the cart based on destination and chosen service (standard, express, cash on delivery). Secure payment by card, Bizum, PayPal or bank transfer. If you choose at-home installation, our technician will take the used battery and dispose of it through an authorised collection point.
Expected lifespan of the Motobatt YB16CLB 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.
Dimensions (length × width × height) are 175×87×155 mm — also written as 175x87x155 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.
It weighs 6,5 kg. Most of the weight is lead. If you plan to fit it yourself, use gloves and a carrying strap (AGM batteries are slightly heavier than conventional due to the absorbent glass-mat fibre).
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 YB16CLB typically fits a wide range of European vehicles thanks to its standard DIN case format.
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.
This battery and its equivalents from Bosch, Tudor or Exide are technically comparable: same dimensions, same voltage and same capacity. The differences are warranty (Varta and Bosch: 2 years; Tudor and Exide: 2 years on the equivalent line), manufacturing plant (Varta and Bosch share origin in the Clarios Group; Tudor and Exide belong to Exide Technologies) and price. For private use any of these brands will give 4-6 years of life. Compare them in the "Equivalents" section.
The average rating of the Motobatt YB16CLB on baterias.com is 4.82/5 from 28 verified customer reviews. The product rating, when available, is shown on the product page next to the stars. You can also check our public Trustpilot profile at shop level (4.5/5 from 11,700+ verified reviews). Most-praised points: reliable cold start, lifespan above 5 years and fast delivery; most common complaints mention BMS-equipped motorcycles that need OBD registration after fitting.
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