Malcolm Hall

I've managed to open my battery case, here are some photos of the inside, I would say the soldered connections I can see are pretty reasonable. I've measured the battery dimensions, 100mm wide 110mm deep (but at a push could possibly squeeze 120mm into the frame in this area), the battery is 300 mm high, but as it is under the saddle, I could manage up-to another 80-100 mm for a taller battery. So I suppose a 09 USB is not possible in the same space. I couldn't see a BMS but didn't undo all the packing and sticky tape, perhaps this is located under the battery in the case on the bike frame, I suppose this is where the motor controller is ?

Thanks D8veh, here is a photo of the slider, and a separate one of the back of the battery to show where the slider locates. I'll try Wisper again, but replacements are still on their website at £544 for 16Ah (the 11Ah batteries at £469 are sold out)

Oh eck !! I was worried that might be the case, at over £500 for a new replacement, do you have any suggestions for a cheaper compatible alternative, can I change the cells in the existing battery ?

I hope someone can give me some advice, or a solution to my problem, when cycling up a steep hill, of which there are many in Sheffield ! if my speed drops below 9 mph, the power can often cut out for about 4 to five revolutions of the pedals. The battery is getting on a bit (4 - 5 years old, but it still manages to last for 12-14 miles on one charge) this problem doesn't seem to be related to the charge level, as it occurs at various states of charge. This makes life difficult as you can imagine, it usually only occurs when I'm in 1st or 2nd gear consequently doing less than 9 mph, don't know if it occurs under throttle only, as I always pedal, anyway the hills are too steep for throttle only.