The Bosch S4 battery series is designed for drivers who expect more than just the basics from their vehicle’s battery. Sitting comfortably between the entry-level S3 and the high-performance S5 series, Bosch S4 batteries offer a balanced combination of reliability, durability, and value. These batteries are engineered to meet the needs of modern vehicles with moderate electrical demands—providing consistent power, longer lifespan, and maintenance-free operation. With robust cold-start capabilities and a wide variety of sizes and configurations, the S4 series is trusted by drivers across Europe and beyond who seek everyday reliability backed by the engineering excellence of Bosch.
One of the more compact and unique models in this series is the Bosch S40 23. This lead-acid battery delivers 45 Ah of capacity and a cold cranking amperage (CCA) of 330 A, making it suitable for small cars, compact city vehicles, and certain Asian imports. Despite its modest size, the S40 23 ensures solid cold-start performance and consistent energy delivery for basic vehicle electronics. It’s a practical solution for drivers whose vehicles don’t require high levels of electrical output and who want a battery that’s both efficient and cost-effective.
In terms of dimensions—238 mm in length, 129 mm in width, and 227 mm in height—the Bosch S40 23 fits within the B24 format, a size commonly found in smaller cars and some Japanese or Korean vehicles. Its height of 227 mm and narrow width already hint that it may be based on a less common format for the European market, reinforcing the idea that this battery is often used in vehicles originally designed for Asian markets. These batteries are typically taller and narrower than standard European batteries.
A notable feature of the Bosch S40 23 is its terminal layout 1, meaning the positive terminal is on the left—which is atypical for most European vehicles. This detail is essential during replacement, as reversed polarity could damage a vehicle’s electrical system if the wrong battery is installed. Additionally, the S40 23 uses a B0 mounting type, meaning it has no bottom hold-down ledge, unlike the more common B13 configuration. This must be considered when replacing or securing the battery, especially in vehicles that rely on bottom-mounted hold-down clamps. Some cars might require adapters or alternate securing methods for proper installation.
When compared to similar batteries like the Exide EB455, Lucas LP057, or Varta B34, the Bosch S40 23 holds its own. It matches the Exide and Varta models in capacity and CCA, all offering 45 Ah and 330 A, while the Lucas LP057 stands out slightly with 390 A, offering improved cold-cranking capability in the same footprint. Nevertheless, Bosch’s reputation for longevity and consistent quality makes the S40 23 a highly competitive option in this segment, particularly for European drivers who prefer a known and trusted brand.
In conclusion, the Bosch S40 23 is a compact, efficient, and dependable battery ideal for smaller vehicles with modest power demands. Its specific configuration—especially the terminal layout and B0 mounting type—makes it well-suited for certain imports or older models with less conventional designs. It may not have the high-end output of larger batteries, but for vehicles that require this particular size and layout, the S40 23 offers excellent reliability and performance from a brand with decades of proven expertise.