The battery market is changing fast and one important development is the increasing use of auxiliary batteries used to complement the main battery, usually in larger start-stop equipped applications. 

Ecobat Battery’s Training Manager, Christopher Jones, says that fitment of an auxiliary battery can cause technical issues and points to an example from a customer where the start-stop system in a Land Rover Discovery that was fitted with an 019 AGM battery had illuminated the battery warning light. Having tested the battery with the EBT780 battery tester it was found that the battery’s state of health (SOH) was down to 70%, a level that prevents the start-stop from working. The battery was replaced correctly and assimilated into the system using an EBT420 battery validation tool, however the battery warning light stayed on. 

Christophe said, “Further investigation was needed, which lead us to check the auxiliary battery located on the opposite side of the engine. Its reading was just 11.80 volts, so revealing an obvious problem. Due to its SOH and also because it was of the same age as the original main battery, the auxiliary battery was then also changed and when we went back to validate the battery again, we found a question in the sub menu about both batteries being changed. After selecting this option, the warning light then when off and the start-stop function began operating normally.”

Christopher adds, “This experience demonstrates that rather than simply being an ‘auxiliary’ battery, both batteries contribute to the start-stop system and due to the condition of the auxiliary battery in this example, the fault code could not be cleared and the start-stop system wouldn’t reactivate. This situation highlights two valuable lessons for workshops, first find out whether the vehicle has an auxiliary battery, and second, check that battery when they test the starting battery.”

Exide now has five auxiliary batteries in its range, which it supplies as original equipment  fitment for several VMs: EK091 (Volvo), EK111 (Mercedes-Benz and Volvo), EK131 (Audi, BMW, Jeep and Mercedes-Benz), EK143 (Renault) and EK151, which is by far the most popular reference, covering the majority of auxiliary battery applications for Jaguar Land Rover.

For further details, please visit Ecobat Battery at: www.ecobatbattery.com