# Marine battery Odyssey ODX-AGM31M 103Ah 1150A AGM

![Marine battery Odyssey ODX-AGM31M 103Ah 1150A AGM](https://baterias.com/1420-home_default/battery-odyssey-odx-agm31m-103ah-1150a.jpg)

> Odyssey ODX-AGM31M marine battery 103Ah 1150A AGM. ODX range. Dimensions 330×173×251 mm, + terminal on the left. Cranking and house duties.

**Category:** [Boat Batteries](https://baterias.com/gb/boat-batteries) → [ODYSSEY](https://baterias.com/gb/odyssey)

- **Canonical URL**: https://baterias.com/gb/battery-odyssey-odx-agm31m-103ah-1150a
- **Language**: en-GB
- **Brand**: ODYSSEY
- **Reference**: BCOM-ODYSSEY-ODX-AGM31M
- **MPN**: ODX-AGM31M
- **Price**: 592,90 € (VAT incl., Spain)
- **Last updated**: 2026-10-28
- **Stock**: Out of stock

## Technical specifications

| Feature | Value |
|---|---|
| Brand | ODYSSEY |
| Reference | ODX-AGM31 M |
| Model | ODX |
| Largo | 330 cm |
| Ancho | 173 cm |
| Alto | 251 cm |
| Peso | 34.1 kg |
| Tecnología | AGM |
| Terminal layout | Positive terminal on the left |
| Terminal type | M |
| Cold cranking amps (EN) | 1150 |
| Capacity (C20) | 103 Ah (c20) |
| Capacity (C10) | 98 Ah (c10) |

## Quick description

**Odyssey ODX-AGM31M 103Ah 1150A** 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

⚡ Capacity
103 Ah C20

🔋 Cold cranking
1150 A SAE

📏 Dimensions
330×173×251 mm

⚙️ Technology
AGM

🧭 Polarity
Positive on the left

⚖️ Weight
34,1 kg

🏷️ Model
ODX

## Description

## Marine battery Odyssey ODX-AGM31M ODX 103Ah 1,150A

103*Ah* Capacity
1,150*A* Cold cranking
34.10*kg* Weight

With **103 Ah** at **V** and **1,150 A** of cold cranking current (EN), the **Odyssey ODX-AGM31M** from the **ODX** 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 330 × 173 × 251 mm format: same 103 Ah capacity and the positive terminal on the left.
- 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.

### Size, terminals and hold-down of the Odyssey ODX-AGM31M

In terms of format, the Odyssey ODX-AGM31M measures 330 × 173 × 251 mm (length × width × height) and weighs 34.10 kg. The positive terminal on the left decides which side the cables end up on: it is the detail that causes most buying mistakes, so check it before ordering. It uses M 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 the Odyssey ODX-AGM31M is for

The Odyssey ODX-AGM31M 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 34.10 kg and M terminals.

### The Odyssey ODX-AGM31M: ODX range and AGM technology

The **ODX** is the Odyssey range the ODX-AGM31M 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.
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.

### Why choose Odyssey batteries

Odyssey batteries combine starting and deep cycling in a single sealed pure-lead unit, with some of the longest warranties on the market. At baterias.com we work directly with the manufacturer or its official distributor: real stock, brand-new product and official warranty.

### Official warranty

The Odyssey ODX-AGM31M comes with the **manufacturer's official warranty** against manufacturing defects. Deep discharge from winter lay-up without charging is not covered.

### Care and maintenance

At the end of the season, charge the battery fully and, if possible, keep it on a charger over the winter lay-up. Charge with a charger that has an AGM mode: it limits the voltage and protects the glass-fibre separators.

### Delivery times and returns

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 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.

## Frequently asked questions

### Is this battery AGM? What is it for?

Yes. The ODX-AGM31M from Odyssey 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 ODX-AGM31M 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 our blog. 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 — with positive on the left 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 Odyssey ODX-AGM31M battery last?

Expected lifespan of the Odyssey ODX-AGM31M 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 Odyssey ODX-AGM31M battery?

Dimensions (length × width × height) are 330×173×251 mm — also written as 330x173x251 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.

### On which side is the positive of the ODX-AGM31M model?

Polarity: positive on the left. To identify it, place the battery in front of you with the terminals facing you and check which side the positive (+, marked with a red ring) is on. Before buying, verify the polarity matches your current battery: switching polarity forces longer cables or system reconfiguration, with short-circuit risk.

### Will the Odyssey ODX-AGM31M 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 ODX-AGM31M typically fits a wide range of European vehicles thanks to its standard DIN case format.

### Which batteries are equivalent to the Odyssey ODX-AGM31M?

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 — automotive battery specialists since 2012.

→ https://baterias.com/gb/technical-team

---
*baterias.com — Automotive batteries · 2026-10-28*