Odyssey ODX-AGM31 · Car battery 100Ah 1150A AGM

Yes, it is AGM. In an AGM battery such as the ODX-AGM31, the electrolyte is not free but absorbed in a glass-fibre mat inside a sealed lead-acid battery. It tolerates heat better and handles more cycles than a conventional battery, which is why it is the required technology with advanced Start-Stop and regenerative braking.

AGM batteries support advanced Start-Stop and regenerative braking thanks to their higher cycle count. The Odyssey ODX-AGM31 is AGM, so yes, it is designed for Start-Stop cars. Basic Start-Stop: EFB. Start-Stop with regenerative braking: AGM, which withstands more cycles. Check the handbook for the technology the car manufacturer requires. Registering it via OBD is advisable on most modern cars (the alternator then applies the optimum profile), but it works from the start.

Our blog guide covers it in detail; if the owner's handbook describes a different procedure, follow the manufacturer. Tool: a 10 mm spanner. Time: 15-30 minutes on almost every car, and up to double if the battery is not under the bonnet but in the boot or under a seat. What matters most is the terminal order: removing, negative (−) before positive (+); refitting, positive (+) before negative (−). In between, with the engine off and the key out, release the clamp and fit the new battery the same way round as the original, positive on the left (polarity).

As a rough estimate, the Odyssey ODX-AGM31 typically lasts 5 to 8 years in mild-climate car use with Start-Stop; it is a guide figure, not a guaranteed period. Many factors play a part: how it is used (lots of short trips, for example), temperature (cold makes every start harder and intense heat evaporates the electrolyte), the condition of the alternator and charging system, power drawn with the engine off and maintenance, as well as the type of car and whether it has Start-Stop.

The Odyssey ODX-AGM31 takes up 330×173×241 mm (length, width and height, terminals included). Before buying, measure the space in your car: one extra millimetre can stop the hold-down clamp from closing.

Polarity of the Odyssey ODX-AGM31: positive on the left. If your current battery has its positive on the other side, this one is not suitable without longer cables or a reconfigured system (short-circuit risk). Seen from the front, terminals towards you, the positive (+) is the post with the red ring.

For your own vehicle: type your number plate into the finder (DGT/DVLA/KBA identify model and engine), check the "Compatible vehicles" tab below, listing vehicles verified by our technical team, or message us on WhatsApp with make, model, engine and year; we reply during business hours (Mon–Fri 10:00–13:30 and 16:30–18:00 (Spanish time, CET)). The car manufacturer's specifications always take priority over our tables.

Interchangeable means the same dimensions, same polarity, same Ah and same CCA; for the ODX-AGM31, 100 Ah (1150 A cranking). Technology matters too: in Start-Stop cars, an EFB cannot be replaced with a conventional battery. The options at the same level are in the "Equivalents" section of this page.

The absorbent glass-fibre mat of an AGM retains the electrolyte, so it cannot leak and withstands considerably more cycles than a conventional battery. It is the recommended choice for advanced Start-Stop with regenerative braking (BMW EfficientDynamics, Mercedes Eco, Audi MHEV, Land Rover ECO, Volvo i-Stop) and copes better than an EFB with tilting, vibration and extreme temperatures. The Odyssey ODX-AGM31 has a capacity of 100 Ah.

The alternator detects the new battery and adapts the charge automatically, so on most cars it is not compulsory. Even so, it is advisable to register it via OBD so charging is optimum from the first minute and the battery lasts longer, particularly on BMW, Mercedes, Audi, Volvo or Land Rover, with more sophisticated BMS. Without registration there is no starting problem: the alternator adjusts the profile within a few days. Any workshop with an OBD scanner does it in a few minutes; DIY, with VCDS or Carista (VAG group), Bimmercode (BMW) or iCarsoft.