# Marine battery Fullriver FT620-51 12V 55Ah 620A AGM

![Marine battery Fullriver FT620-51 12V 55Ah 620A AGM](https://baterias.com/3163-home_default/battery-fullriver-ft620-51-12v-55ah-620a.jpg)

> Fullriver FT620-51 marine battery 12V 55Ah 620A AGM. Full Throttle Series range. Dimensions 229×138×230 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-fullriver-ft620-51-12v-55ah-620a
- **Language**: en-GB
- **Brand**: FULLRIVER
- **Reference**: BCOM-FULLRIVER-FT620-51
- **MPN**: FT620-51
- **Price**: 264,70 €
- **Stock**: Out of stock

## Technical specifications

| Feature | Value |
|---|---|
| Brand | FULLRIVER |
| Reference | FT620-51 |
| Model | Full Throttle Series |
| Voltage (V) | 12 V |
| Largo | 229 cm |
| Ancho | 138 cm |
| Alto | 230 cm |
| Peso | 18 kg |
| Tecnología | AGM |
| EAN | 810233030473 |
| Terminal type | M8 + TP28 (SAE) |
| Cold cranking amps (EN) | 620 |
| Capacity (C20) | 55 |
| Case type | 51 |

## Quick description

**Fullriver FT620-51 12V 55Ah 620A** is a marine battery with reinforced anti-vibration case for moorings and offshore use. Tolerates the typical daily cycles on a boat (engine start + night-time services such as lights, sonar, fridge) and holds voltage even when the hull is rolling in open sea.

## 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
55 Ah C20

🔋 Cold cranking
620 A EN-1

📏 Dimensions
229×138×230 mm

⚙️ Technology
AGM

⚖️ Weight
18 kg

🏷️ Model
Full Throttle Series

## Description

## Marine battery Fullriver FT620-51 Full Throttle Series 55Ah 620A 12V

12*V* Voltage
55*Ah* Capacity
620*A* Cold cranking
18*kg* Weight

With **55 Ah** at **12 V** and **620 A** of cold cranking current (EN), the **Fullriver FT620-51** from the **Full Throttle Series** 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 229 × 138 × 230 mm format: same 55 Ah capacity.
- AGM technology: absorbed electrolyte, no spills, can be mounted at an angle.
- Reinforced case against vibration and swell.
- Powers onboard services: lights, sounder, GPS, fridge.
- Tolerates the daily cycling of a boat in season.

### What the Fullriver FT620-51 is for

The Fullriver FT620-51 is designed for motor and sailing boats, both for engine starting and onboard services. If it is your starter battery, run the services from a separate battery; if it is a service battery, avoid routinely discharging it beyond 50%. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 18 kg and M8 + TP28 (SAE) terminals.

### Size, terminals and hold-down of the Fullriver FT620-51

In terms of format, the Fullriver FT620-51 measures 229 × 138 × 230 mm (length × width × height) and weighs 18 kg. It uses M8 + TP28 (SAE) terminals, the system that anchors and connects it in the vehicle. Checking the three dimensions and the terminal position before buying avoids the most common mistake when replacing a battery.

### What Fullriver does differently

With its own plants and a catalogue focused on high-performance AGM, Fullriver is a familiar brand in power wheelchairs, boats and photovoltaic systems that need thousands of cycles. At baterias.com we work directly with the manufacturer or its official distributor: real stock, brand-new product and official warranty.

### The Fullriver FT620-51: Full Throttle Series range and AGM technology

Within the Fullriver catalogue, the **Full Throttle Series** series groups the references designed for this use. The FT620-51 is the 55 Ah model of that family, with the same performance as its siblings in other sizes.
In an AGM battery the electrolyte is absorbed in glass-fibre separators: there is no free liquid, it cannot spill and it can be mounted at an angle. That construction lowers internal resistance, speeds up recharging and multiplies cycle life compared with a conventional battery.

### How to make it last longer

At the end of the season, charge the battery fully and, if possible, keep it on a charger over the winter lay-up. As a service battery, avoid routine discharges below 50% to extend its cycle life.

### Manufacturer's warranty

The Fullriver FT620-51 comes with the **manufacturer's official warranty** against manufacturing defects. Deep discharge from winter lay-up without charging is not covered.

### When you get it and how to return it

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 Fullriver FT620-51 an AGM battery and what are the benefits of AGM?

Yes. The FT620-51 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 FT620-51 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.

### How long does the Fullriver FT620-51 battery last?

Expected lifespan of the Fullriver FT620-51 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 size is this battery?

Dimensions (length × width × height) are 229×138×230 mm — also written as 229x138x230 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 FT620-51 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 FT620-51 typically fits a wide range of European vehicles thanks to its standard DIN case format.

### Which batteries are equivalent to the Fullriver FT620-51?

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.


## 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

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*baterias.com — Automotive batteries · 2026-10-06*