# How we write our battery datasheets

> Where the data on every bateriasonline.es battery page comes from, how we work out cross-brand equivalents and who checks each datasheet.

- **Canonical URL**: https://bateriasonline.es/en/how-we-write-our-battery-datasheets
- **Language**: en
- **Last update**: 2026-11-10

Every product page on bateriasonline.es brings together the technical data of a battery so that you can compare it and choose the right one. This page explains where that data comes from, how we work out equivalents and who checks the datasheets.

## Where the data comes from

- **The manufacturer's datasheet (PDF).** Voltage, capacity (Ah), cold cranking amps to the EN standard, dimensions, weight, polarity, terminal type and, where it exists, the ETN (European Type Number), exactly as printed. When the datasheet is available you can download it from the product page.
- **Our catalogue.** The manufacturer's part number, the EAN barcode, the brand, the range and what each battery is for: car, Start-Stop, motorcycle, truck, boat, caravan, UPS…

We only publish data that appears in one of these sources. If a figure is missing, we do not estimate it or fill it in ourselves: the page simply leaves it out.

## How we work out equivalents

A battery is listed as an equivalent of another only if it meets all of these conditions:
- Same voltage.
- Capacity within 6 % (3 Ah for small batteries).
- Cold cranking amps between 90 % and 120 % of the original, when both batteries state them.
- Length, width and height within 4 mm.
- Same polarity, i.e. the positive terminal on the same side.
- Same use: a car battery is never suggested as an equivalent of a boat or motorcycle battery, or the other way round. For a car without Start-Stop you may see EFB or AGM batteries, which are an upgrade; for a car with Start-Stop we only suggest Start-Stop batteries.

For 12 V starter batteries we also give the European case size (L0 to L6, LB0 to LB5, B19, B24, D23, D26 or D31) when the battery's dimensions match that size within 5 mm.

## Who checks the datasheets

The product pages are prepared and checked by the team at Kronotech Solutions S.L., the company that owns bateriasonline.es. When a manufacturer updates a datasheet, changes a part number or we spot a mistake, we correct the page. The «Datasheet updated» date on each product shows when it was last changed.

## Before you buy

Compare the dimensions, polarity and terminal type with your current battery, or [search by number plate or VIN](https://bateriasonline.es/en/battery-finder-plate-or-vin) to see the batteries that fit your vehicle.

## Spotted a mistake?

If a figure does not look right, email us at [comercial@bateriasonline.es](mailto:comercial@bateriasonline.es), call us on +34 951 870 157 or use the [contact form](https://bateriasonline.es/en/contact-us) with the product reference. We will check it and correct the page.
The same rules apply to our [car battery guides](https://bateriasonline.es/en/battery-guides): cross-brand equivalent tables, case sizes and side-by-side comparisons of Varta models.

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