I have a Samsung 36v 15AH lithium battery. Purchased in August 2015. Its done just over 4000 miles and, being only used for leisure purposes (approximately 20 miles each time), its probably been charged 200 times. Recently I've noticed that the "power indicator" is dropping much more often on steeper parts of my ride - although it still reverts back to full when back on the flat. I'm thinking that (due to age and number of charges) its probably time to replace this battery but would be interested in any expert comments. Also, can these batteries be "reconditioned"? Plus, if I replace the battery, what options have I got for the old battery, given that it still does the job (albeit with probably less potential ride distance). Or do I just dispose of it? (safely?)