# Fullriver FT840-24M · Boat battery 12V 75Ah 840A

![Fullriver FT840-24M · Boat battery 12V 75Ah 840A](https://bateriasonline.es/2571-home_default/fullriver-ft840-24m.jpg)

> Fullriver FT840-24M: 75 Ah boat battery, 840 A (EN), 276×172×227 mm, AGM. Equivalent to Fullriver FT840-24F.

**Category:** [Marine and boat batteries](https://bateriasonline.es/en/marine-boat-batteries) → [Fullriver](https://bateriasonline.es/en/fullriver-batteries)

- **Canonical URL**: https://bateriasonline.es/en/fullriver-ft840-24m
- **Language**: en
- **Brand**: Fullriver
- **Reference**: BOL-FULLRIVER-FT840-24M
- **MPN**: FT840-24M
- **Price**: 595,55 € (VAT incl., Spain)
- **Last updated**: 2026-10-27

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Fullriver |
| Range | Full Throttle Series |
| Application | Boats |
| Technology | AGM |
| Voltage | 12 V |
| Capacity | 75 Ah |
| Cold cranking amps (EN) | 840 A |
| Length | 276 mm |
| Width | 172 mm |
| Height | 227 mm |
| Weight | 24.5 kg |
| Terminal type | DT |

## Quick description

The Fullriver FT840-24M is a boat battery with 12 V, 75 Ah and 840 A cold cranking current, measuring 276 × 172 × 227 mm.

## Description

## Where the Fullriver FT840-24M fits

The Fullriver FT840-24M is a battery for boats: engine starting or on-board service, depending on its design, with resistance to damp and hull vibration. With 75 Ah, the FT840-24M suits boats that had a battery of that capacity.
The FT840-24M belongs to the Fullriver Full Throttle Series range. [See all Fullriver batteries](https://bateriasonline.es/en/fullriver-batteries)

## Equivalents and alternatives to the Fullriver FT840-24M

Other AGM batteries that fit the FT840-24M's tray with the same polarity: an AGM can only be replaced by another AGM.

| Model | Technology | Capacity | Cold cranking (EN) | Dimensions (mm) |
|---|---|---|---|---|
| Fullriver FT840-24F | AGM | 75 Ah | 840 A | 276 × 172 × 227 |

## Fullriver FT840-24M vs FT825-78 and DC85-12: which one to choose?

Torn between the FT840-24M and another similar Fullriver? This is what changes:

| Model | Capacity | Cold cranking (EN) | Dimensions (mm) | Weight |
|---|---|---|---|---|
| Fullriver FT840-24M (this one) | 75 Ah | 840 A | 276 × 172 × 227 | 24.5 kg |
| Fullriver FT825-78 | 65 Ah | 825 A | 261 × 172 × 211 | 21.1 kg |
| Fullriver DC85-12 | 85 Ah | 510 A | 260 × 169 × 236 | 25.1 kg |

- Fullriver FT825-78: 10 Ah less, 15 A less cranking power, a different case (261 × 172 × 211 mm).
- Fullriver DC85-12: 10 Ah more, 330 A less cranking power, a different case (260 × 169 × 236 mm).

## AGM technology in the FT840-24M

The FT840-24M is AGM: the electrolyte is absorbed in glass fibre mats, so it is sealed and spill-proof. Being sealed, the FT840-24M can be fitted in the boot or under a seat with no risk of spills.

## Before ordering the FT840-24M, check this

- Length, width and height of the FT840-24M: 276 × 172 × 227 mm.
- Capacity of the FT840-24M: 75 Ah; the same as your current battery or slightly more is fine.
- Cold cranking: 840 A (EN), equal to or higher than the original.

## Part numbers and codes for the Fullriver FT840-24M

Look for any of these FT840-24M codes on your current battery or in the manufacturer's catalogue:

| Commercial reference | FT840-24M |
|---|---|
| Terminal type | DT |

## Frequently asked questions about the Fullriver FT840-24M

### FT840-24M or FT825-78: which one suits me?

Compared with the FT840-24M, the Fullriver FT825-78 has 10 Ah less and 15 A less cranking power. The FT840-24M cranks harder; the FT825-78 is only a good option if your original battery says 825 A or less. Mind the space: the FT825-78 measures 261 × 172 × 211 mm.

### How much does the Fullriver FT840-24M weigh?

24.5 kg, with 75 Ah of capacity. For reference, the Fullriver FT825-78 (65 Ah) weighs 21.1 kg.

### Which battery is equivalent to the Fullriver FT840-24M?

Only other AGM batteries with its dimensions and polarity: Fullriver FT840-24F. Neither an EFB nor a conventional battery replaces the FT840-24M.

### Which charger does the Fullriver FT840-24M need?

A charger with an AGM mode that limits voltage to about 14.4-14.7 V. Never an old unregulated charger: overcharging dries out an AGM beyond repair.

## Keep comparing: alternatives to the FT840-24M

- [More marine and boat batteries](https://bateriasonline.es/en/marine-boat-batteries)
- [More Fullriver models](https://bateriasonline.es/en/fullriver-batteries)
- [Fullriver FT840-24F](https://bateriasonline.es/en/fullriver-ft840-24f) · 75 Ah, 840 A, 276×172×227 mm

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*bateriasonline.es — Batteries and accessories · 2026-11-10*