# Marine battery Fullriver DC20-12 12V 20Ah 135A AGM ![Marine battery Fullriver DC20-12 12V 20Ah 135A AGM](https://baterias.com/80-home_default/battery-agm-fullriver-dc20-12-12v-20ah.jpg) > Fullriver DC20-12 marine battery 12V 20Ah 135A AGM. DC Series range. Dimensions 181×77×167 mm. Cranking and house duties. **Category:** [Boat Batteries](https://baterias.com/gb/boat-batteries) → [FULLRIVER](https://baterias.com/gb/fullriver) - **Canonical URL**: https://baterias.com/gb/battery-agm-fullriver-dc20-12-12v-20ah - **Language**: en-GB - **Brand**: FULLRIVER - **Reference**: BCOM-FULLRIVER-DC20-12 - **MPN**: DC20-12 - **Price**: 85,80 € - **Stock**: Out of stock ## Technical specifications | Feature | Value | |---|---| | Brand | FULLRIVER | | Reference | DC20-12 | | Model | FULLRIVER DC | | Voltage (V) | 12 V | | Largo | 181 mm | | Ancho | 77 mm | | Alto | 167 mm | | Peso | 6.44 kg | | Tecnología | AGM | | Terminal type | M5 | | Cold cranking amps (EN) | 135 | | Capacity (C20) | 20 Ah (c20) | | Capacity (C5) | 16 5 Ah (c5) | ## Quick description **Fullriver DC20-12 12V 20Ah 135A** 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 20 Ah C20 🔋 Cold cranking 135 A EN-1 📏 Dimensions 181×77×167 mm ⚙️ Technology AGM ⚖️ Weight 6,44 kg 🏷️ Model DC Series ## Description ## Marine battery Fullriver DC20-12 DC 20Ah 135A 12V 12*V* Voltage 20*Ah* Capacity 135*A* Cold cranking 6.44*kg* Weight With **20 Ah** at **12 V** and **135 A** of cold cranking current (EN), the **Fullriver DC20-12** from the **DC** range is built for motor and sailing boats, both for engine starting and onboard services. It replaces the original battery without adaptation in boats with a 181 × 77 × 167 mm format: same 20 Ah capacity. - Powers onboard services: lights, sounder, GPS, fridge. - Tolerates the daily cycling of a boat in season. - AGM technology: absorbed electrolyte, no spills, can be mounted at an angle. - Reinforced case against vibration and swell. ### What the Fullriver DC20-12 is for With 20 Ah, the Fullriver DC20-12 covers motor and sailing boats, both for engine starting and onboard services. At the end of the season, charge it fully before winter storage. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 6.44 kg and M5 terminals. ### Dimensions, polarity and mounting In terms of format, the Fullriver DC20-12 measures 181 × 77 × 167 mm (length × width × height) and weighs 6.44 kg. It uses M5 terminals, the system that anchors and connects it in the vehicle. Before replacing it, measure your current battery tray: if all three dimensions and the terminal positions match, the swap is direct and needs no adapters. ### The Fullriver DC20-12: DC range and AGM technology Within the Fullriver catalogue, the **DC** series groups the references designed for this use. The DC20-12 is the 20 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. ### What Fullriver does differently Fullriver specialises in deep-cycle AGM batteries for mobility, marine, solar and traction. Its DC and HC series are known for their tolerance to deep discharge and long cycle life. We guarantee that every Fullriver arrives new, charged and with the manufacturer's full warranty. ### Warranty and coverage The Fullriver DC20-12 comes with the **manufacturer's official warranty** against manufacturing defects. Deep discharge from winter lay-up without charging is not covered. ### Usage and maintenance tips Charge with a charger that has an AGM mode: it limits the voltage and protects the glass-fibre separators. At the end of the season, charge the battery fully and, if possible, keep it on a charger over the winter lay-up. ### 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 ### Is the DC20-12 model AGM? What does this technology offer? Yes. The DC20-12 from Fullriver 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 fit the DC20-12 model in my boat? 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 is the service life of the DC20-12 model? Expected lifespan of the Fullriver DC20-12 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 Fullriver DC20-12 battery? Dimensions (length × width × height) are 181×77×167 mm — also written as 181x77x167 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. ### Will the Fullriver DC20-12 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 10:00–13:30 and 16:40–18:00 (Spanish time, CET)). The DC20-12 typically fits a wide range of European vehicles thanks to its standard DIN case format. ### Which batteries are equivalent to the Fullriver DC20-12? 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. ## Equivalent batteries - [FULLRIVER DC17-12](https://baterias.com/gb/battery-agm-fullriver-dc17-12-12v-17ah) ## Reviews - **Average rating**: 4.8 / 5 (35 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 · 2026-09-29*