With many new vehicles made after 2011 more of them are fitted with stop / start technology to reduce emissions & to save the enviroment. However this causes problems for many vehicle owners, for example unless your using an expensive £100+ car charger you simply can’t charge these batteries correctly without causing damage to the cells inside the battery. Another major problem is customers can’t replace there car battery themselves without very expensive diagnostic equipment. All newer car batteries are sealed units and you can’t carry out any maintenance on these yourself.
You could DIY swap a car battery and think there is no warning lights appearing on the dash it must be fine, however and incorrectly reset / programmed battery will cause the new battery to either get over or under charged which will effect the life of the battery long term. considing the average AGM battery cost is £200 – 500 why chance fitting one DIY and have to replace it again shortly after.
AGM car batteries charge in a slower way than any normal lead car battery due to the cells used inside. They need to be able to repeatedly charge and discharge without loosing performance. When your vehicle is in the city you will more than likely notice your engine will keep stopping and starting at traffic lights this demands a lot of power from the battery which an older style lead battery wouldn’t be able to manage and remain reliable.
Car batteries have come a very long way in the last 15 years and the future of electric cars will be very interesting. If you wish to charge your vehicle with an AGM battery / start & stop you will need to invest in a charger which is designed with these batteries in mind.