I often get called out to look at Batteries, people sometimes buy the cheap ones online, please avoid these! They are cheap for a reason, whilst the feedback is generally good that is because people submit feedback shortly after purchase, not later on. I have replaced so many cheap batteries that only last a year, for a bit more you can buy ones that last several years so you are not saving money but wasting it. My choice of batteries is MK as I have found that they last much longer than any other brand, I frequently find MK batteries over 4 years old and up to 17 years old! Whilst the initial cost may be a little bit more they will last at least 1 or 2 times as long as cheaper batteries so an extra few pounds spent at the beginning can save you hundreds later on. Recnt example, customer paid 180 pounds for a pair of batteries on ebay, they failed after 12 months. I replaced them with MK batteries for 250 pounds, they will last at least 3 years so saving 70 pounds cost a lot in the long run. There is a particular brand I loath as they sell cheap online but fail after 12 months.
MK Battery provides the highest quality and most environmentally responsible sealed battery solutions for specialized deep-cycle applications. Advanced design and manufacturing make MK sealed VRLA and Gel batteries the standard by which all other batteries are measured.
We then get into should you have AGM or Gel batteries. It will depend on what your use is, for someone that uses a scooter or chair daily for long periods then GEL are the best option. For those who use it occasionally then AGM are perfect.
PLEASE NOTE: This is just a brief breakdown of batteries, should you need new batteries I will discuss with you all of the options and work out what is best for you, not what is best for me! When I worked for a large mobility company their policy was fit GEL to everything, not because they are the best for every customer, it was because they made more profit on them.