# Marine battery Optima BTDC-5.5 12V 75Ah 975A AGM ![Marine battery Optima BTDC-5.5 12V 75Ah 975A AGM](https://baterias.com/3804-home_default/battery-optima-blue-top-btdc-55-8052-188-12v-75ah.jpg) > Optima BTDC-5.5 marine battery 12V 75Ah 975A AGM. BLUE TOP range. Dimensions 325×165×238 mm. Cranking and house duties. **Category:** [Boat Batteries](https://baterias.com/gb/boat-batteries) → [OPTIMA](https://baterias.com/gb/optima) - **Canonical URL**: https://baterias.com/gb/battery-optima-blue-top-btdc-55-8052-188-12v-75ah - **Language**: en-GB - **Brand**: OPTIMA - **Reference**: BCOM-OPTIMA-BTDC-5.5 - **EAN**: 4016987113592 - **MPN**: BTDC-5.5 - **Price**: 263,70 € - **Stock**: In stock ## Technical specifications | Feature | Value | |---|---| | Brand | OPTIMA | | Reference | BTDC-5.5 | | Model | OPTIMA BLUE TOP | | Voltage (V) | 12 V | | Largo | 325 mm | | Ancho | 158 mm | | Alto | 218 mm | | Peso | 27.9 kg | | Tecnología | AGM ESPIRAL | | EAN | 4016987113592 | | Terminal layout | 8 | | Terminal type | 1 & 21 | | Cold cranking amps (EN) | 975 A | | Capacity (C20) | 75 Ah (c20) | | Capacity (C5) | 68 Ah (c5) | | ETN | 8521880008882 | ## Quick description **Optima BTDC-5.5 12V 75Ah 975A** is a marine battery, vibration- and deep-discharge resistant, suitable both for outboard engine starting and for onboard auxiliary services (navigation lights, GPS, sonar, fridge). Sealed and maintenance-free. ### Why this marine battery? - **Marine design** built for boat swell and vibration - **Dual function** starts the engine and powers onboard services - **Sealed and safe** maintenance-free even when the boat rolls 🔌 Voltage 12 V ⚡ Capacity 75 Ah C20 🔋 Cold cranking 975 A EN-1 📏 Dimensions 325×165×238 mm ⚙️ Technology AGM ESPIRAL ⚖️ Weight 27,9 kg 🏷️ Model OPTIMA BLUE TOP ## Description ## Battery Optima Blue Top DC 5.5 75Ah 975A 12V The Battery OPTIMA BTDC-5.5 75Ah 975A 12V BLUE TOP belongs to the Optima Bluetop battery range This high -end battery incorporates Spiracell technology (cells with spiral structure inside that enhances the performance of the batteries) created by Optima, which offers more prolonged service time, faster recharges and even twiceconventional nautical batteries. Specially designed to overcome the great demands of nautical applications offering a reliable energy supply, totally free of leaks and does not require maintenance.Totally free of leaks and does not require maintenance. Among our Bluetop products catalog you will find double -use batteries that S can use in any deep cycle application (navigation accessory, on -board applications, outboard engine, bow propuls) or starting. ### Ideal for: - Start applications - Agricultural machines - Construction vehicles - Emergency vehicles - Generators - Trams ### Battery advantages and characteristics OPTIMA BTDC-5.5 75Ah 975A 12V - Long useful life.Lasts up to three times more than conventional flat plates batteries - Constant performance - Greater power.More power during the first one, two, five and ten seconds of the starting process compared to similar lead-acid batteries. - Perfect for seasonal uses.If it is fully charged, it may not be used for a period of up to 12 months at room temperature (or lower) and yet start a car. - x15 times more resistant to vibrations than standard lead-acid batteries - Free of mantenimient - It can be installed almost in any position ### How to find the right battery for your vehicle or device? Optimal AGM AGM batteries are not comparable to any other battery in the world.Its Spi-Dpiell technology is among the most advanced lead-acid battery technologies available in the market. If you are not sure what cover color is better under your hood, do not hesitate to contact us and we will be happy to advise you. ### Why choose an optimal battery? If you look for the maximum possible power or a battery to work in the toughest working conditions.Do not hesitate, choose an optima battery ### OPTIMA - LEADING BRAND IN THE SECTOR With a 40 -year history of technological innovation and engineering, Optima® products offer unstoppable power for extreme enthusiasts and other people who require the final source of energy. In the 1970s, Optima Batteries presented the first main maintenanceless lead batteries for commercial and military use and the first high-performance AGM automotive batteries, but optimal innovation did not stop there.Optima the industry revolutionized with the introduction of its exclusive Spiord Technology® that grants certain key benefits such as: - Incredibly high starter characteristics in a small battery - Up to 15 times more resistance to vibrations than a conventional battery - Have a higher life cycle compared to traditional batteries If you want additional information about Battery Optima Blue Top DC 5.5, you can download the product's technical sheet at the following link: [ Download technical sheet Optima Blue Top DC 5.5 75Ah 975A 12V](/fichastecnicas/data-sheet-battery-optima-btdc-5_5-75ah-975a-12v-en.pdf) ## Frequently asked questions ### Is the BTDC-5.5 model AGM? What does this technology offer? Yes. The BTDC-5.5 from Optima uses AGM (Absorbent Glass Mat) technology: a sealed lead-acid battery where the electrolyte is absorbed in a glass-fibre mat. It withstands more charge/discharge cycles than a conventional one, handles heat better and is the required technology for boats with advanced Start-Stop and regenerative braking. Expected lifespan: 5-8 years under normal conditions. ### How do I verify this battery is the right one? 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 BTDC-5.5; 3) if you cannot find your model, message us on WhatsApp with brand, model, engine and year — we reply during business hours (Mon–Fri 9:00–18:00 CET). ### How is the Optima BTDC-5.5 battery installed in the vehicle? In most boats 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 boats with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile. ### What warranty does the Optima BTDC-5.5 battery have? The official manufacturer warranty is 1 year and covers manufacturing defects. It covers cell failures, internal short-circuits and abnormal capacity drops. Wear from misuse (prolonged overcharging, wrong charger or faulty alternator) is not covered. If the battery fails, we replace it at no cost after a technical inspection. ### How long does Optima BTDC-5.5 delivery take? In mainland Spain and Portugal it arrives in 24 h if you order before 17:00 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. ### Can I return the Optima BTDC-5.5 battery if it doesn't fit or doesn't work? 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. ### What is the price of this battery? The current price at baterias.com is 263,70 € (VAT included; 217,93 € 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). ### Where can I buy the Optima BTDC-5.5 battery? At baterias.com — authorised distributor with real stock, 24h delivery in mainland Spain and Portugal if you order before 17:00, 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. ### How many years does this battery last? Expected lifespan of the Optima BTDC-5.5 is 5 to 8 years in mild-climate boat use with Start-Stop. 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 dimensions of the Optima BTDC-5.5 battery? Dimensions (length × width × height) are 325×165×238 mm — also written as 325x165x238 mm — following the European DIN standard. Always measure the space in your boat before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals. ### How much does the Optima BTDC-5.5 battery weigh? It weighs 27,9 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). ### What ETN and EAN codes does the Optima BTDC-5.5 battery have? The manufacturer reference (MPN) is BTDC-5.5 and its ETN code is 8521880008882 (short form 852 188 000), the European identifier used in spare-part catalogues. The EAN-13 barcode is 4016987113592. It belongs to the OPTIMA BLUE TOP range. Any of these codes identifies exactly this battery when requesting quotes or comparing prices. ### Will the Optima BTDC-5.5 battery fit my boat? 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 9:00–18:00 CET). The BTDC-5.5 fits 4 verified vehicle versions in our database. ### What are the equivalents of the BTDC-5.5 model? 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 boats. See the "Equivalents" section to view recommended options at the same performance level. ### Which is better: Optima BTDC-5.5 or an alternative from another brand? 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. ### What do users say about the Optima BTDC-5.5 battery? The average rating of the Optima BTDC-5.5 on baterias.com is 4.8/5 from 37 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 11,776+ verified reviews). Most-praised points: reliable cold start, lifespan above 5 years and fast delivery; most common complaints mention BMS-equipped boats that need OBD registration after fitting. ## Compatible vehicles This battery fits 4 vehicles. Most searched: - [JOHN DEERE Series 9 (2011)](https://baterias.com/gb/batteries-for-construction-and-agricultural-machinery/john-deere/series-9) - [JOHN DEERE Series 9 (2011)](https://baterias.com/gb/batteries-for-agricultural-and-construction-vehicles/john-deere/series-9) - [JOHN DEERE Series 5 (2009)](https://baterias.com/gb/batteries-for-construction-and-agricultural-machinery/john-deere/series-5) ## Reviews - **Average rating**: 4.8 / 5 (37 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 · 2026-09-26*