Tudor TK508 AGM Microhybrid · Start-Stop battery 50Ah 800A

Yes, it is AGM. In an AGM battery such as the TK508, the electrolyte is not free but absorbed in a glass-fibre mat inside a sealed lead-acid battery. Compared with a conventional battery it withstands more charge/discharge cycles and handles heat better; it is the required technology for cars with advanced Start-Stop and regenerative braking.

Yes: being AGM, the Tudor TK508 is designed for Start-Stop cars. 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. Registering it via OBD is advisable on most modern cars (the alternator then applies the optimum profile), but it works from the start.

With a 10 mm spanner, swapping in the Tudor TK508 takes 15 to 30 minutes on most cars; if the battery sits in the boot or under a seat, allow up to twice as long. If the car has Start-Stop or BMS: a) the technology must match the original (AGM or EFB) or be higher, because a conventional battery would fail within months; b) undo the negative cable at its nut, leaving the IBS sensor in place; c) it is advisable to register the battery via OBD so the alternator applies the proper charging profile. 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 (polarity). Before you start, check the car handbook: the manufacturer's procedure always comes first. Our full step-by-step guide is on the blog.

As a guide, you can expect the Tudor TK508 to last 5 to 8 years in mild-climate car use with Start-Stop, although the real figure may be higher or lower. What weighs most: temperature (cold makes starts harder and intense heat evaporates the electrolyte), frequent short trips, the condition of the alternator and charging system, power draw while parked and maintenance, not forgetting the type of car and Start-Stop.

Length × width × height: 260x173x206 mm. Height is measured to the top of the terminals. Measure your car's battery tray first; if the battery exceeds it by even a millimetre, the hold-down clamp may not close.

Three routes: the "Compatible vehicles" tab on this page, with the vehicles verified by our technical team; your number plate in the finder, from which DGT/DVLA/KBA detect model and engine; and WhatsApp, with make, model, engine and year, during business hours (Mon–Fri 10:00–13:30 and 16:30–18:00 (Spanish time, CET)). If our table and the car handbook disagree, go with what the manufacturer says.

The "Equivalents" section of this page gathers the recommended options with equivalent performance; remember that in Start-Stop cars an EFB should not be replaced with a conventional battery. To replace the Tudor TK508 without modifications, the other battery must be identical in size, polarity, Ah and CCA.

It is the verified Exide equivalent for the TK508 tray. Compared with the TK508 it has the same Ah and cranking power. It costs 2,10 € less. Decide by price, brand preference and availability: both fit and crank the same.

Compared with an EFB it resists tilted positions, heavy vibration and extreme temperatures better, and it is the recommended option where there is regenerative braking (BMW EfficientDynamics, Mercedes Eco, Audi MHEV, Land Rover ECO, Volvo i-Stop). Many more charge/discharge cycles than a conventional battery and no leaks: that is what AGM technology brings, with the electrolyte absorbed in glass fibre. This TK508 delivers 800 A cold cranking (EN).

It is not strictly necessary on most cars, because the alternator detects the change and adapts the charge. The advisable step is to register it via OBD: the charging profile is optimum from the first minute and the battery lasts longer, especially on brands with sophisticated BMS (BMW, Mercedes, Audi, Volvo, Land Rover). Any garage with an OBD scanner can do it in a few minutes. If you prefer to do it yourself: VCDS / Carista (VAG), Bimmercode (BMW) or iCarsoft. If you do not register the TK508, it will keep starting fine while the alternator adjusts the profile over a few days.