Odyssey ODP-AGM27 · Car battery 85Ah 850A AGM

Yes, it is AGM. In an AGM battery such as the ODP-AGM27, 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.

Yes. It is a AGM battery of 85 Ah, designed for vehicles with Start-Stop. AGM batteries support advanced Start-Stop and regenerative braking thanks to their higher cycle count. If the car recovers energy when braking, AGM is recommended for its higher cycle count; for basic Start-Stop, EFB. The manufacturer's specification comes first. Once fitted it is ready to go; registering it via OBD, advisable on most modern models, lets the alternator charge with the optimum profile.

Before you start, check the car handbook: the manufacturer's procedure always comes first. Our full step-by-step guide is on the blog. 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. The right order: engine off and key out; disconnect the negative (−) first, then the positive (+); release the hold-down clamp, lift out the old battery and seat the new one in the same position (positive on the left), keeping the polarity; reconnect the positive (+) first and the negative (−) last. Start-Stop or BMS specifics: do not remove the IBS sensor on the negative terminal (just loosen the cable nut); after the swap, register the battery via OBD so the alternator charges with the right profile; and never step down in technology: if the car had AGM or EFB, the new one must be the same or better, as a conventional battery lasts only a few months.

Estimated lifespan of the Odyssey ODP-AGM27: 5 to 8 years in mild-climate car use with Start-Stop. Treat it as an approximate guide, as every case is different. 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 ODP-AGM27 takes up 318×173×224 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.

The ODP-AGM27 has the positive on the left: that is its polarity. Face the battery with its terminals nearest you and see which side the positive post (+, red ring) is on. A change of polarity from the original means longer cables or a reconfigured system and can cause a short circuit: check it before ordering.

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.

To replace the Odyssey ODP-AGM27 without modifications, the other battery must be identical in size, polarity, Ah and CCA. Not just any technology will do: an EFB cannot be replaced with a conventional battery in Start-Stop cars. The "Equivalents" section further down lists the recommended alternatives.

The absorbent glass-fibre mat of an AGM retains the electrolyte, so it cannot leak and withstands considerably more cycles than a conventional battery. For regenerative braking systems such as BMW EfficientDynamics, Mercedes Eco, Audi MHEV, Land Rover ECO or Volvo i-Stop, AGM is the recommendation; it also copes better than an EFB with tilting, vibration and extreme temperatures. This ODP-AGM27 delivers 850 A cold cranking (EN).

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.