A lots been written about start-stop batteries, and now that nearly two thirds (60 per cent) of the cars sold in Europe now have either start-stop or energy recuperation technology or both, these cars are now finding themselves with the second user and it’s important we understand the only choice is either AGM or EFB and that a Standard Flooded is not an option.
Enhanced Flooded Batteries (EFB) is an enhanced version of standard wet-flooded technology, the primary benefits of EFB technology are improved charge acceptance and greater cyclic durability when operating in a reduced state of charge (typical of Stop Start applications). As an approximation, EFB batteries will provide 85,000 engine starts, compared to 30,000 starts from standard flooded battery.
Absorbent Glass Mat (AGM) benefit from the inclusion of unique design features not found in wet-flooded batteries. These include glass mat separators, recombinant lid technology and higher pack pressures to facilitate improved cyclic lifespan, they are better suited to meeting the demands of higher specification vehicles that include one or more of the following technologies: Start Stop, Regenerative Braking and Passive Boost.
The absorbent glass mat gives a number of key benefits to the design of the lead acid battery:
Within normal operating conditions, the use of the individual cell valve design and glass mat plate separation ensures gas recombination occurs and ensures that no water is lost therefore negating the need for electrolyte reservoirs and freeing the user from maintenance.
One way venting system providing partial pressure in each cell ensuring 100% leak proof and safe handling.
The acid absorption of the glass mat means that the battery packs can be operated under higher pressures than conventional flooded batteries this has benefits including significantly prolonging battery cycle durability by minimising paste shedding.
The increased pack pressures of the AGM battery increase the batteries resistance to vibration.
More reaction surface area ensuring higher starting capacity within the same footprint as conventional Flooded batteries.
Understandably, drivers are tempted to choose batteries by the variance in price, the price differentials of the regular flooded battery, EFB and start-stop batteries is considerable.
It is ESSENTIAL to replace batteries with like-for-like technology that’s AGM or EFB, the reality is starting an engine is the most demanding thing that the battery will do, to do this repeatedly during a succession of short, low-speed drives requires a heavier duty AGM or EFB type and they are more expensive.
Fact If a standard flooded battery is fitted to a Start-Stop vehicle, it will definitely fail and failure could be within 2-4 months of installation.
This type of battery failure will lead to loss of vehicle functions (including Start-Stop).