Fulmen FL1000 · Start-Stop battery 100Ah 900A EFB

Yes. The FL1000 is an EFB (Enhanced Flooded Battery): flooded lead-acid reinforced with plate additives. More affordable than an equivalent AGM and with more cycles than a conventional battery (though fewer than AGM), it is what cars with basic Start-Stop use, without regenerative braking.

EFB batteries cover basic Start-Stop (no regenerative braking). The Fulmen FL1000 is EFB, 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. It needs nothing to work, though on most modern cars registering it via OBD is advisable so the alternator adjusts its charging profile.

On most cars it is a 15-30 minute job needing only a 10 mm spanner (up to twice as long when the battery is under a seat or in the boot). With the engine stopped and the key removed, always start with the negative (−) terminal, then the positive (+). Free the clamp, swap the battery without turning it round (this one has positive on the right) so the polarity stays the same, and reconnect in reverse: positive (+) first, negative (−) last. 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. Our blog guide covers it in detail; if the owner's handbook describes a different procedure, follow the manufacturer.

As a rough estimate, the Fulmen FL1000 typically lasts 4 to 6 years in basic Start-Stop car use; it is a guide figure, not a guaranteed period. It can vary considerably with usage (short or long journeys), temperature, the condition of the alternator and charging system, power drawn with the engine off and maintenance, plus the car itself and Start-Stop. Cold demands more at every start and intense heat evaporates the electrolyte.

Length × width × height: 353x175x190 mm (L5 case). Height is measured to the top of the terminals. Hold-down: B13. Measure your car's battery tray first; if the battery exceeds it by even a millimetre, the hold-down clamp may not close.

Polarity of the Fulmen FL1000: positive on the right. It must match your current battery: reversed polarity means lengthening cables or reconfiguring the system, with a risk of short circuit. Seen from the front, terminals towards you, the positive (+) is the post with the red ring.

Not sure? Try your number plate in the finder (DGT/DVLA/KBA detect model and engine) or the "Compatible vehicles" tab, checked by our technical team; if your car is not there, send us make, model, engine and year on WhatsApp and we will reply during business hours (Mon–Fri 10:00–13:30 and 16:30–18:00 (Spanish time, CET)). Our database holds 13 verified vehicle versions for the Fulmen FL1000. If our table and the car handbook disagree, go with what the manufacturer says.

Interchangeable means the same dimensions, same polarity, same Ah and same CCA; for the FL1000, 100 Ah (900 A cranking). 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.

Rule of thumb: car with an EFB from new, EFB (AGM is an optional, marginal upgrade); car with an AGM from new, AGM. Thicker grids plus carbon and polyethylene additives in the plates: that is what sets an EFB apart from a conventional flooded battery. The result is more cycles and more resistance to deep discharges, without reaching AGM level. Many basic Start-Stop systems (no regenerative braking) come with it from the factory, such as Renault Energy TCe, Peugeot/Citroën PureTech, Fiat MultiAir, Hyundai/Kia ISG and Ford EcoBoost.

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.