AGM Batteries


Crompton talks to Vital News about how AGM batteries have evolved to keep up with modern technological demands.

It is forecast that by 2020 over 90% of vehicles manufactured will use start-stop technology. AGM batteries can be fitted on all start-stop vehicles, but they must be ‘like-for-like’ where AGM was originally fitted. This presents vast opportunities to the aftermarket. With the number of start-stop vehicles on the road, it is easy for many of us to take the technology for granted even though it has been many years in the making.


In a bid to improve fuel consumption Toyota devised a simple engine cut-off system as early as 1974. They integrated this technology into certain Crown models, and by the 1980’s Fiat and Volkswagen experimented with this technology in a fuel cost saving exercise.

The simple solution was to fit a larger battery that had the ampere hour (Ah) capacity to cope with the demands. However, they soon found that the cyclic capability of the battery needed improving. As a result, none of the early start-stop models stuck around for very long. However, they did later provide a catalyst in automotive technology.


As the EU began cracking down on CO2 emissions, vehicle manufacturers began looking for solutions for the new mandate. They revisited start-stop technology once again and by 2006, the emergence of vehicles fitted with start-stop technology began to take shape.

This time, the issues with Ah capacity and cyclic capability were overcome with the introduction of Absorbent Glass Mat (AGM) technology for automotive applications.


A conventional car battery is designed to only start the car. Once this has been accomplished, the energy used is replenished by the vehicle’s charging system. Start-stop batteries not only have to start the vehicle but must be able to be the sole energy supplier when the car is in a stop phase.

The number of engine starts for start-stop vehicles can be well over 300,000, in comparison to traditional vehicles, which sit at about 30,000 – the battery must be able to cater for this demand.

AGM batteries have their electrolytes absorbed in glass matting around the internal lead plates which reduces active material shedding – the main cause of failure for this application. They are also designed to cope with increased charging during regenerative braking.


AGM batteries are fully sealed and never require topping up because there is no water loss under normal operation. As a result, plates can be larger as there is no need for a reservoir of electrolytes above them. Larger plates provide better performance in cold starting performance. They can also be fitted in any orientation, which is advantageous for certain applications.

The Crompton Start-Stop+ AGM batteries can not only cope with increased demand from fuel saving devices on the vehicle, but they are also able to power a wider range of ancillary equipment than the ECM, even when the engine is in the idle position.

For more information about start-stop batteries and the Crompton range, please speak to your local representative.


FPS is one of the UK’s leading providers of service-led supply chain solutions. Founded in 1934, and employing over 1,200 people, it operates from 23 sites in the UK. Acting as a distribution partner for a number of major brands, its core business is providing automotive parts, car accessories and consumables to the reseller network. Through recent expansion FPS now successfully provides wholesale distribution services in the Maintenance & Accessories sector, serving a number of blue-chip companies. Dedicated to service excellence and innovation, the company offers a wide range of services meeting the varying needs of manufacturers, suppliers, resellers and business consumers across the supply chain. For further details go to or contact

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