There are eight 12-volt 4.5ah battery in this set Valve regulated sealed lead acid, AGM Length = 90mm Width = 70mm Height = 101mm More details Our batteries are sealed AGM type which means they are non-spillable, not-hazardous, recyclable, rechargeable and safe for air transport (although always ensure you check with the airline you are taking them on). Valve regulated sealed lead Acid, VRLA, with AGM technology, they will not spill and can be safely mounted on their side. A little help on installation: Once you receive your brand new batteries it is fairly straight forward to swap them with your old ones. Battery Care: Battery care is quite simple if you follow a few basic rules. To begin with, fully charge upon delivery and before first use until they are full (should be no more than a few hours), it doesn’t take very long as we ensure our batteries are kept at a high charge. Secondly and most importantly, make sure you charge until full after every use, a fully charged battery will keep that full charge for a good couple of weeks so no need to recharge if it’s not in use for a week. Lastly, if they are not being used for more than 4-weeks then a top up charge will be needed to keep the cells fresh. These batteries are for the standard size 12v 4ah 4.5ah 5ah with the sizes quoted above.