# Optima YTU-4.2 · Motorhome battery 12V 55Ah 765A

![Optima YTU-4.2 · Motorhome battery 12V 55Ah 765A](https://bateriasonline.es/3898-home_default/optima-ytu-4-2.jpg)

> Optima YTU-4.2 (ETN 814254000): 55 Ah motorhome battery, 765 A (EN), 254×175×200 mm, positive terminal on the left.

**Category:** [Leisure batteries for motorhomes and caravans](https://bateriasonline.es/en/leisure-batteries-motorhome-caravan) → [Optima](https://bateriasonline.es/en/optima-batteries)

- **Canonical URL**: https://bateriasonline.es/en/optima-ytu-4-2
- **Language**: en
- **Brand**: Optima
- **Reference**: BOL-OPTIMA-YTU-4.2
- **EAN**: 4016987113530
- **MPN**: YTU-4.2
- **Price**: 206,26 € (VAT incl., Spain)
- **Last updated**: 2026-10-27

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Optima |
| Range | OPTIMA YELLOW TOP |
| Application | Motorhomes and caravans |
| Technology | Spiral AGM |
| Voltage | 12 V |
| Capacity | 55 Ah |
| Cold cranking amps (EN) | 765 A |
| Length | 254 mm |
| Width | 175 mm |
| Height | 200 mm |
| Weight | 20.6 kg |
| Polarity | Positive terminal on the left |
| Terminal type | 1 & 21 |
| ETN code | 814254000 |

## Quick description

The Optima YTU-4.2 (ETN 814 254 000, also written 814254000) is a motorhome battery with 12 V, 55 Ah and 765 A cold cranking current, measuring 254 × 175 × 200 mm, with the positive terminal on the left.

## Description

## Who the Optima YTU-4.2 is for

The Optima YTU-4.2 is a leisure battery for motorhomes and caravans: it powers fridge, lights, water pump and heating for days without starting the engine. The YTU-4.2 powers the living area, separate from the vehicle's starter battery.
The YTU-4.2 belongs to the Optima OPTIMA YELLOW TOP range. [More Optima batteries](https://bateriasonline.es/en/optima-batteries)

## Inside the YTU-4.2: spiral AGM technology

The YTU-4.2 is a spiral-cell AGM battery. Perfect for 4x4s, marine use and vehicles with lots of electronics.

## Equivalents and alternatives to the Optima YTU-4.2

Other AGM batteries that fit the YTU-4.2's tray with the same polarity: an AGM can only be replaced by another AGM.

| Model | Technology | Capacity | Cold cranking (EN) | Dimensions (mm) |
|---|---|---|---|---|
| Optima YTS-4.2 | Spiral AGM | 55 Ah | 765 A | 254 × 175 × 200 |

## Part numbers and codes for the Optima YTU-4.2

The YTU-4.2 is listed under these codes on labels, in garages and in catalogues:

| Commercial reference | YTU-4.2 |
|---|---|
| ETN code | 814254000 (also 814 254 000) |
| EAN | 4016987113530 |
| Case size according to Optima | 34/78 (BCI) |
| Base hold-down | B00 |
| Terminal type | 1 & 21 |
| Also known as | Optima 814254000 · Optima 814 254 000 |
| Not to be confused with | Optima RTU-4.2 (50 Ah, 815 A) |

## Check this before ordering the Optima YTU-4.2

- The YTU-4.2 delivers 765 A cold cranking (EN standard); do not go below what your original battery states.
- Your current battery should say about 55 Ah; a little more is also fine.
- The YTU-4.2 has the positive terminal on the left: compare it with your current battery.
- Measure the space: the YTU-4.2 takes up 254 × 175 × 200 mm.

## Frequently asked questions about the Optima YTU-4.2

### What is the ETN code of the Optima YTU-4.2?

814254000, also written 814 254 000. The ETN (European Type Number) is printed on the label and used in parts catalogues.

### How much does the Optima YTU-4.2 weigh?

20.6 kg, with 55 Ah of capacity.

### Which battery is equivalent to the Optima YTU-4.2?

Only other AGM batteries with its dimensions and polarity: Optima YTS-4.2. Neither an EFB nor a conventional battery replaces the YTU-4.2.

### What is the cold cranking current of the Optima YTU-4.2?

765 A to the EN standard, with 55 Ah capacity.

### Which side is the positive terminal on the Optima YTU-4.2?

On the YTU-4.2, 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.

## Keep comparing: alternatives to the YTU-4.2

- [All leisure batteries for motorhomes and caravans](https://bateriasonline.es/en/leisure-batteries-motorhome-caravan)
- [The whole Optima range](https://bateriasonline.es/en/optima-batteries)
- [Optima YTR-5.0](https://bateriasonline.es/en/optima-ytr-5-0) · 66 Ah, 845 A, 309×172×219 mm

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