# 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 € (VAT incl., Spain) - **Last updated**: 2026-10-28 - **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 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. ## Frequently asked questions ### Is the DC20-12 model AGM? What does this technology offer? Yes, it is AGM. In an AGM battery such as the DC20-12, the electrolyte is not free but absorbed in a glass-fibre mat inside a sealed lead-acid battery. It withstands more cycles than a conventional battery and copes better with heat. ### In what position can it be installed on the boat? Being AGM, it is sealed and does not spill: it can be mounted tilted (never upside down) and copes well with vibration and wave impacts. Secure it firmly and keep the terminals away from water. ### What are the dimensions of the Fullriver DC20-12 battery? Measure your boat's battery tray first; if the battery exceeds it by even a millimetre, the hold-down clamp may not close. Length × width × height: 181x77x167 mm. Height is measured to the top of the terminals. ### Fullriver DC20-12 or Fullriver FT230D: which one to choose? Same case and same technology as the DC20-12: an alternative by size, not an official equivalent. Compared with the DC20-12 it has 2 Ah more and 45 A of cold cranking more. It costs 70,00 € more. If the polarity matches and your equipment had a similar capacity, it works as a replacement; if in doubt, ask us with your model. ### Fullriver DC20-12 or Fullriver FT230: which one to choose? It has the same dimensions, voltage and technology as the DC20-12, although it is not a manufacturer-approved equivalent. Compared with the DC20-12 it has 95 A of cold cranking more. It costs 90,30 € more. Check the positive terminal side and the original capacity before ordering; otherwise it is a straight swap. ## Technical team (editorial authorship) The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team — automotive battery specialists since 2012. → https://baterias.com/gb/technical-team --- *baterias.com — Automotive batteries · 2026-11-13*