Battery has been flattened two more times recently, both times it measured 36.7v on the meter. They took 2:55 to charge from flat. There has been some different behaviour on the bike though.
When I first had the bike and the battery was about to die, it would cut out suddenly. After a few months, this was no longer the case, the throttle would give less and less power until it gave basically none at all, but I could then rotate the pedals and squeeze the last bit of juice out of it, then turn the key off and on and do the same a couple of times. At that time it was cutting out at between 32-34 volts, which I believe is correct.
Now it's gone back to the behaviour where it loses power suddenly. And that's not all. In the whole time I owned the bike, it has only suffered a low voltage cutofff when going up a hill once, when I attempted a lengthy climb in cold conditions on a battery that I'd already used half the range on.
Since I posted this topic, I've suffered 3 more cutouts. The first was when I went to visit my dad, I made the 4 mile trip to his house, but it cut out at the bottom of the road on the final climb, which wasn't very steep. I pushed it the last 100 yards. The second time, nearly the exact circumstances, but I made the climb and it only cut out as I was pulling into the driveway. The third time I climbed a really steep road of loose gravel, and it cut out when I reached the top.
On all those occasions when I turned power key off and back on, it did not restore the power. Maybe I didn't leave it long enough? But anyway, lifting the seat, undoing and redoing the connector fixed it.
I cleaned the pins of the battery connector with a cotton bud and alcohol, and it got a load of black stuff off, but I never cleaned out the bike connector. I don't think it would have helped anyway, as I experienced the last cutoff after cleaning it.
I'm thinking next time I flatten it, I'm going to disconnect and reconnect the battery and see if there's any more power left.
Aside from that, my battery level indicator on the dash behaves differently. When it was fully charged, the lights NEVER dropped on heavy loads, it only dropped as the range decreased. Now it not only drops to the last light after a few minutes of riding then hitting an incline, but goes straight to the low voltage warning, indicating the cutout symptoms I've experienced. In fact, on two of those cutouts the battery meter was in the low voltage warning as I climbed the incline.
I think the change in performance has been so sudden, that it might not be because of the battery's age. I suspect either a bad connection, or a cell that is faulty??? When I have time I will check over the connections, but I don't fancy stripping the pack to measure each cell individually.
Few other things for Scottyf: (or even flecc)
I haven't got good use out of the battery. I bought the bike new beginning of February 2010. Battery was manufactured in August 2007. It had been tampered with before I received it. The range was less than half of what was advertised. The dealer ripped me off basically.
I know you were joking about me being a tight git about buying a new battery, but it aint that! I haven't had 4 years use out of it, I've had over a year and a half (20 months), and in the 2250-2750 miles I've ridden, it clearly hasn't lasted a reasonable amount of time. The number of charges is due to the 10-12 mile range I've always got from it (not the 25-29 miles advertised), and now its only just 10 miles.
I wish I bought the 12ah SLA version of the bike and saved £200. Would I have got better range with that if it were a new one?
And your last point about 10ah chargers, I've never seen one for an e-bike application before, unless it's a custom one?
Anyway, this now leaves me with a few options. I fancied another e-bike, or even a petrol scooter. But I am also considering a new battery. My dilemma is whether I make a new detailed topic (with pictures and dimensions of my batt case) about that or not?
Anyway, in brief, I won't be able to obtain a new battery that fits. The case is a tight fit under the seat and anything bigger won't do. I've looked at Ping battery packs, the 10ah and 15ah, unfortunately the dimensions listed means that they won't fit in the case. I also wanted a new case as mine is worn from being slid in and out of the bike many times, but can't find that. Looked at BMSbattery, think they aren't as respected as Ping, but the batteries are cheaper. But more importantly, even though the 10ah BMSbattery has two sets of dimensions listed for the pack (the pic says one thing, the detailed description another) it would definitely fit. And it is only £111 without the shipping and duty. If I get exact measurements of their packs and the inside of my battery case, there is a possibility the 15ah will fit. But I don't want more hassle with dodgy batteries.
Could even have a 10ah recell, at £350, with 1 year guarantee. But I can get more capacity at a much cheaper price if I do it myself.
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