Varta K4 · Truck battery 12V 143Ah 950A

Varta K4 ProMotive SLI (formerly ProMotive HD) 143Ah 950A 12V Lorry Battery

The Varta K4 lorry battery is the 12 V, 143 Ah model delivering 950 A of cold cranking power (EN), from Varta's ProMotive SLI (formerly ProMotive HD) range, designed for lorries, buses, large vans and machinery. It replaces the original battery in lorries with the 514 × 218 × 210 mm format without any modifications: the same 143 Ah capacity and the same terminal layout (positive on the left).

• High cranking current for large-capacity diesel engines.
• Withstands the vibration of thousands of kilometres on the road.
• Reinforced grids and casing for the severe demands of haulage.
• Dependable through repeated starts and while powering cab equipment.

Vehicles compatible with the Varta K4 battery

According to our database, the Varta K4 is fitted to more than 834 vehicles from makes such as Ford, Fiat, Fendt, Caterpillar, Volvo and Lännen Tehtaat, among others. If you are looking for a battery for a Ford or a Fiat with these dimensions, the K4 is one of the usual replacement references. Added to that list are models from Carraro, Deutz-Fahr, Atlas, Same, Allis-Chalmers, Lamborghini, Fahr and Case International.

Format and fitting of the Varta K4

Its external dimensions are 514 × 218 × 210 mm and it weighs 39.85 kg. The positive terminal on the left determines which side the cables end up on: this is the detail behind more wrong purchases than any other, so it is worth checking before you order. It takes a B03 hold-down and terminal 1, the system that anchors it to the vehicle's battery tray. For the swap to be direct, the space left by the current battery must respect those three dimensions and the same terminal layout; otherwise adapters will be needed or the hold-down would have to change.

The Varta K4 and the ProMotive SLI range

The ProMotive SLI series is Varta's starter line for professional transport, bringing the former ProMotive HD and SHD together under a single name. It is built to crank large-capacity diesel engines and to take the daily punishment of the lorry, the bus and site machinery.

The key to this range is sheer toughness: reinforced plates and mountings that resist thousands of kilometres of vibration and deep discharge cycles, keeping fleet downtime from starting failures to a minimum.

Commercial vehicles demand high cranking current and endurance against the vibration of thousands of kilometres. This series uses reinforced grids and a robust construction to cope with repeated starts of large diesel engines and with the draw of the cab's auxiliary equipment. This battery used to belong to Varta's ProMotive HD or ProMotive SHD range; following the brand's commercial renaming (2025), it now forms part of the new ProMotive SLI series.

Why choose a Varta battery

A good share of the vehicles on Europe's roads left the factory with a Varta fitted: the brand has been supplying the assembly lines of the major car groups for decades. Replacing with a Varta means, in practice, giving the vehicle back the battery its manufacturer had specified.

Behind Varta is Clarios, one of the largest manufacturers of starter batteries in the world and a supplier to the assembly lines of numerous car brands. That German engineering heritage translates into reliable starting year after year.

More than 100 manufacturing parameters are checked on every Varta battery before it leaves the plant, a level of rigour that explains why so many workshops and manufacturers trust the brand as their first-choice replacement.

Manufacturer's warranty

The Varta K4 battery comes with the official manufacturer warranty. An important warning for commercial vehicles: most lorries run two batteries connected in series (a 24 V installation). If you replace only one, the new battery ends up working alongside the old one — which has already lost capacity and has higher internal resistance — and that imbalance means one overcharges while the other falls short, shortens the life of the new unit and may be treated by the manufacturer as improper use, voiding the warranty. That is why it is always advisable to change both batteries at the same time.

Care and maintenance

In professional use, checking the state of charge and the battery hold-down regularly prevents breakdowns on the road. Vibration and the high temperatures of the engine bay are what shortens a battery's life most, so secure mounting is key. Keeping the terminals clean and tight and checking the charging system extends battery life in vehicles that clock up long hours. A well-maintained battery reduces the risk of downtime caused by a battery that will not start the engine.