Thanks very much.
The Varta link below refers to AGM batteries as Fleece, so confused!
Maintenance-free and leakproof AGM batteries (“AGM” stands for “Absorbent Glass Mat”, because the electrolyte is bound in an absorbent glass fleece) are powerful batteries for automatic start-stop systems and have very good cold start characteristics. Thanks to the cycle stability of an AGM battery, a warm engine can be switched off and started again several times at short intervals, without the risk of difficulties when restarting. They also provide sufficient reserves to continue to supply electrical consumers during the frequent stops and still guarantee reliable starting.