Most ATVs use a 12-volt motorcycle-style battery in a common group size such as YTX12-BS, YTX14-BS, or YTX20L-BS. The exact size depends on your model, so always verify with the owner’s manual or the OEM battery label.
Understanding ATV battery sizing
ATVs predominantly rely on 12-volt sealed lead-acid batteries, typically of the AGM or flooded type. The “size” you need is defined by the group size code printed on the battery (for example, YTX12-BS). This code tells you the physical fit in the battery tray, the position of the terminals, and the electrical capabilities your charging system expects. If you’re unsure, start with the OEM part number or measure the tray to ensure a proper match.
Common ATV battery sizes and group codes
As a quick reference, several group sizes show up frequently in ATVs. The group code helps identify fit, connector layout, and compatibility with your ATV’s electrical system.
- YTX4L-BS — a compact option found on smaller or older quads.
- YTX5L-BS — another small-form option used on light-duty ATVs.
- YTX7L-BS — a very common mid-size battery for many mid-range ATVs.
- YTX9-BS / YTZ9S — mid-range capacity used by a wide range of mid-size models.
- YTX12-BS — a standard choice for many mid-to-large ATVs.
- YTX14-BS — larger capacity for bigger models or higher electrical demand.
- YTX20L-BS — among the largest commonly used motorcycle-style batteries for high-demand machines.
Note: Exact compatibility can vary by model year and manufacturer. When replacing, aim to match the group size (or use the OEM-equivalent) to ensure proper fit and charging compatibility.
How to confirm the exact size for your ATV
To identify the precise battery size you need, follow these steps to confirm group size, capacity, and fit before purchasing a replacement.
- Check the owner’s manual or service guide for the OEM battery part number or group size (for example, YTX12-BS).
- Inspect the label on your current battery to read the exact model name and group size printed on it.
- Measure the battery tray’s interior length, width, and height to ensure the new battery will fit without rubbing or obstruction.
- Verify terminal configuration and polarity (positive/negative) and ensure the new battery’s terminals match your cables and clamps.
- Consider your ATV’s electrical load and climate; larger machines may tolerate higher capacity (Ah) or different CCA ratings, but stay within the manufacturer’s recommended range.
With the exact size confirmed, you can choose between an AGM or a flooded-lead-acid battery that matches the group size and your ATV’s electrical requirements.
Summary
In short, most ATVs require a 12-volt battery in a motorcycle-style group size, with common codes like YTX12-BS, YTX14-BS, or YTX20L-BS. Always verify using the owner’s manual, the current battery’s label, or the OEM part number, and confirm tray dimensions and terminal layout before purchasing. Proper sizing ensures reliable starts, proper charging, and a longer battery life for your ATV.