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Tech Talk

Battery special: supercharged technology

Battery special: supercharged technology

Our Tech Talk expert Paul Britten, Parts Product Manager at Volkswagen Group UK, looks at the evolution of battery technology and the impact of stop-start systems.

The days of fitting a standard lead-acid battery will soon become a distant memory due to advances in vehicle technology and the introduction of stop-start systems. They are a standard feature on 90% of new vehicles as manufacturers strive to increase fuel efficiency and reduce engine emissions.

It’s estimated that one in three vehicles entering a workshop are fitted with a stop-start system yet there is still some uncertainty when it comes to replacing the starter battery on these vehicles. A ‘one size fits most’ approach is no longer feasible, so what are the most important considerations for an independent workshop?


Battery specification

Vehicles with stop-start systems require a much higher specification of starter battery than a conventional vehicle to cope with the frequency of stop-start cycles. For these applications, the battery will be one of two types; an absorbent glass mat (AGM) battery or an enhanced flooded battery (EFB).

AGM batteries are a unique design with four to five times the cyclic durability of a flooded product and typically 16% higher starting power, even at lower temperatures. They are often used on premium and high-performance models and can also be found on the earliest vehicles fitted with stop-start technology.

EFB batteries are an enhanced version of the standard wet-flooded technology, with a greater cyclic durability when operating at a reduced state of charge (typical of stop-start applications). An EFB battery is capable of 270,000 engine starts, compared to around 30,000 from a standard flooded product, and offers a more cost-effective solution for entry-level stop-start vehicles. Despite these higher engine demands, the life expectancy for both battery types remains the same, providing the correct battery is fitted.

One of the most important things to remember is that if a vehicle is equipped with stop-start technology, it must have a stop-start battery. The EFB and AGM batteries are also not interchangeable and failure to follow these important rules will result in the vehicle not functioning correctly and make it more prone to the dreaded ‘non-start’ scenario.


Battery Management Systems

Vehicles fitted with a stop-start system will also have a Battery Management System (BMS) that continuously monitors the state of the battery. The BMS will only feed in a charge when the state has dropped to a predetermined level which avoids using the engine to power the alternator unnecessarily, thus reducing fuel consumption and emissions.

A replacement battery must be registered or ‘validated’ into the BMS via a diagnostic tool to ensure that the battery is charged with the correct algorithm. If not, the vehicle will generate a fault code leading to a malfunction of the stop-start system and the premature failure of the battery.



An additional challenge that must be overcome is the location of the battery, as only 58% of vehicles have the battery in the traditional ‘under the bonnet’ location. 40% are in the boot and the remaining 2% are situated somewhere in the passenger compartment, resulting in both locations requiring the removal of parts to access the battery.

This means that for some vehicles, such as the Audi Q5, it can take up to an hour and a half to replace the battery. It’s therefore imperative that the correct specification of battery is fitted to avoid a repeat repair and a significant loss of labour time.


TPS offers a comprehensive range of Genuine, FourPlus, Quantum and Yuasa batteries to cater for all of your battery requirements. The best way to ensure you are fitting the correct battery to your customer’s vehicle is by visiting tps.trade and entering your customer’s registration number, or contacting your local TPS Centre.


And when placing your order, remember our current battery benefits which can help your business boost battery sales:

  • When you purchase any 12 batteries from our range, you'll receive a complimentary battery stand to help store and display your products
  • We're offering extended credit terms, with three months to invoice payment to help give your business extra flexibility
  • Remind your customers of our great warranty options, with either two or three years warranty available across our entire battery range