Tudor TK151 Auxiliar · Auxiliary battery 15Ah 200A AGM

Yes. The Tudor TK151 is AGM (Absorbent Glass Mat): sealed lead-acid, with the electrolyte absorbed in glass fibre. 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 TK151 is designed for Start-Stop cars. AGM batteries support advanced Start-Stop and regenerative braking thanks to their higher cycle count. Once fitted it is ready to go; registering it via OBD, advisable on most modern models, lets the alternator charge with the optimum profile. As a rule: EFB for basic Start-Stop, AGM when there is also regenerative braking (more cycles); in any case, what the car manufacturer specifies.

As a guide, you can expect the Tudor TK151 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.

Check the room available in your car, because a single millimetre too much can stop the clamp from closing. Its dimensions are 150×90×145 mm, also written 150x90x145 mm; the height already includes the terminals.

On the Tudor TK151, the polarity is positive on the left. To check, stand the battery in front of you with the terminals nearest you: the positive (+) is the one with the red ring. A change of polarity from the original means longer cables or a reconfigured system and can cause a short circuit: check it before ordering.

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)). Always cross-check with what the car manufacturer states in the owner's handbook.

See the "Equivalents" section of this page for the recommended options at the same performance level. Mind the technology: in Start-Stop cars an EFB is not swapped for a conventional battery. To replace the Tudor TK151 without modifications, the other battery must be identical in size, polarity, Ah and CCA.

Same case and same fitting as the TK151, from Exide. Compared with the TK151 it has the same Ah and cranking power. It costs 10,35 € less. If you want to save or the TK151 is out of stock, it is the safe alternative: same dimensions, same polarity and official warranty.

This TK151 delivers 200 A cold cranking (EN). In an AGM (Absorbent Glass Mat) battery the electrolyte is held in a glass-fibre mat: no spills, and many more charge/discharge cycles than a conventional battery. 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).

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 TK151, it will keep starting fine while the alternator adjusts the profile over a few days.