With use of my backpack being occasional. I was interested in the best way to keep the battery charged, having in mind battery life and memory. I had a chat with a very helpful person at Williamson Pumps. He suggested using a trickle charger. The advantage being when the battery is fully charged it turns itself off. The charger supplied with the Shurflo is basic and would carry on charging even when the battery is fully charged thus compromising battery integrity. One of Williamson Pumps customers does this and thinks for him it increases battery life up to three times!
Thankyou for all the very helpful information posted.
Jack Avery