# Fulbat FDM12-825-M31 · Dual-purpose marine battery 12V 105Ah 825A

![Fulbat FDM12-825-M31 · Dual-purpose marine battery 12V 105Ah 825A](https://bateriasonline.es/452-home_default/fulbat-fdm12-825-m31.jpg)

> Fulbat FDM12-825-M31: 105 Ah dual-purpose marine battery, 825 A (EN), 330×173×237 mm, positive terminal on the left, carbon AGM. Equivalent to Exide EP900.

**Category:** [Dual-purpose marine batteries (starting and service)](https://bateriasonline.es/en/dual-purpose-marine-batteries) → [Fulbat](https://bateriasonline.es/en/fulbat-batteries)

- **Canonical URL**: https://bateriasonline.es/en/fulbat-fdm12-825-m31
- **Language**: en
- **Brand**: Fulbat
- **Reference**: BOL-FULBAT-FDM12-825-M31
- **MPN**: FDM12-825-M31
- **Last updated**: 2026-10-27

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Fulbat |
| Range | FULBAT FDM Marine AGM Carbon |
| Application | Boats (starting and service) |
| Technology | Carbon AGM |
| Voltage | 12 V |
| Capacity | 105 Ah |
| Cold cranking amps (EN) | 825 A |
| Length | 330 mm |
| Width | 173 mm |
| Height | 237 mm |
| Weight | 30.6 kg |
| Polarity | Positive terminal on the left |
| Terminal type | DUAL |

## Quick description

The Fulbat FDM12-825-M31 is a dual-purpose marine battery with 12 V, 105 Ah and 825 A cold cranking current, measuring 330 × 173 × 237 mm, with the positive terminal on the left.

## Description

## Who the Fulbat FDM12-825-M31 is for

The Fulbat FDM12-825-M31 combines starting and service in a single battery, the usual solution on boats with a single bank and moderate on-board consumption.
The FDM12-825-M31 belongs to the Fulbat FULBAT FDM Marine AGM Carbon range. [The full range of Fulbat batteries](https://bateriasonline.es/en/fulbat-batteries)

## Equivalents and alternatives to the Fulbat FDM12-825-M31

Other AGM batteries that fit the FDM12-825-M31's tray with the same polarity: an AGM can only be replaced by another AGM.

| Model | Technology | Capacity | Cold cranking (EN) | Dimensions (mm) |
|---|---|---|---|---|
| Exide EP900 | AGM | 100 Ah | 800 A | 330 × 173 × 240 |
| Exide EM960 | AGM | 100 Ah | 800 A | 330 × 173 × 240 |
| Fullriver FFD110-12 | AGM | 110 Ah | 850 A | 328 × 172 × 241 |

## Fulbat FDM12-825-M31 vs FDM12-800-M27 and FDM12-550-M24: which one to choose?

Torn between the FDM12-825-M31 and another similar Fulbat? This is what changes:

| Model | Capacity | Cold cranking (EN) | Dimensions (mm) | Positive | Weight |
|---|---|---|---|---|---|
| Fulbat FDM12-825-M31 (this one) | 105 Ah | 825 A | 330 × 173 × 237 | left | 30.6 kg |
| Fulbat FDM12-800-M27 | 92 Ah | 800 A | 306 × 168 × 233 | left | 28.5 kg |
| Fulbat FDM12-550-M24 | 79 Ah | 550 A | 260 × 168 × 233 | left | 23 kg |

- Fulbat FDM12-800-M27: 13 Ah less, 25 A less cranking power, a different case (306 × 168 × 233 mm).
- Fulbat FDM12-550-M24: 26 Ah less, 275 A less cranking power, a different case (260 × 168 × 233 mm).

## Carbon AGM technology in the FDM12-825-M31

Inside, the FDM12-825-M31 combines AGM with a carbon additive. It is the option for solar, marine and service use with incomplete charges.

## What to look at before buying the FDM12-825-M31

- The FDM12-825-M31 needs 330 × 173 × 237 mm of space: measure it with the hold-down clamp in place.
- Polarity of the FDM12-825-M31: positive terminal on the left (if yours has it on the other side, the cables will not reach).
- Capacity of the FDM12-825-M31: 105 Ah; the same as your current battery or slightly more is fine.
- The FDM12-825-M31 delivers 825 A cold cranking (EN standard); do not go below what your original battery states.

## Part numbers and codes for the Fulbat FDM12-825-M31

This is how the Fulbat FDM12-825-M31 appears on the label and in parts catalogues:

| Commercial reference | FDM12-825-M31 |
|---|---|
| Terminal type | DUAL |

## Frequently asked questions about the Fulbat FDM12-825-M31

### FDM12-825-M31 or FDM12-800-M27: which one suits me?

Compared with the FDM12-825-M31, the Fulbat FDM12-800-M27 has 13 Ah less and 25 A less cranking power. The FDM12-825-M31 cranks harder; the FDM12-800-M27 is only a good option if your original battery says 800 A or less. Mind the space: the FDM12-800-M27 measures 306 × 168 × 233 mm.

### How much does the Fulbat FDM12-825-M31 weigh?

30.6 kg, with 105 Ah of capacity. For reference, the Fulbat FDM12-800-M27 (92 Ah) weighs 28.5 kg.

### Which battery is equivalent to the Fulbat FDM12-825-M31?

Only other AGM batteries with its dimensions and polarity: Exide EP900, Exide EM960 and Fullriver FFD110-12. Neither an EFB nor a conventional battery replaces the FDM12-825-M31.

### Which side is the positive terminal on the Fulbat FDM12-825-M31?

On the FDM12-825-M31, the positive terminal is on the left with the terminals facing you: compare it with your current battery, because with reversed polarity the cables will not reach.

## Other options if you are unsure about the FDM12-825-M31

- [All dual-purpose marine batteries (starting and service)](https://bateriasonline.es/en/dual-purpose-marine-batteries)
- [More Fulbat models](https://bateriasonline.es/en/fulbat-batteries)
- [Fulbat FDM12-700](https://bateriasonline.es/en/fulbat-fdm12-700) · 140 Ah, 700 A, 512×188×218 mm

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*bateriasonline.es — Batteries and accessories · 2026-11-11*