Experiences with batteries
My wife got her Sprint just under 2 years ago, and uses it to ride to the various schools that she works at. She soon found that two batteries were useful, as she would go out with one, come back later, and have the other 'ready to go'. She also sets out with the charger on some days, and charges at one school before going to another later. Days vary from 15 miles up to 20 miles round trip. Yesterday she was doing end-of-term shows, and did 41 miles total (she said).
She runs with two NiMH batteries, and the first pair lasted about 18 months each. She's now on a second pair, and loans me one of hers when I can commute to work (The Li-on that I bought with my Cadence just doesn't suit my commute). We were very lucky that 50 cycles were able to get us a NiMH in May.
Because this is around Macclesfield, there are 100m plus hill climbs between several schools and home (and, indeed, on the end of my commute home, which is 18 miles each way - with a charge in the office).
I've not done anything like the miles - I'm a fair weather cyclist, and I won't attempt my commute when the clocks have changed (i.e in the dark). We did a run on Sunday morning which was 18 miles plus, with the hill at Alderley Edge (Artist's Lane) near the end, and the batteries were running out at the end, but it's inconceivable that we'd do any of this without battery assist.
I hope this is interesting (but I fear it's not really). Is that the sort of thing people want to know? I can post more specific details if anyone wants...