Ah, Peukert's law…. I’ve changed it to 7ah. I haven’t done the calculation but I do have a set of those Ritars and, from experience, would say that’s quite a conservative figure for a new set. They are kept for occasional use, for when I can persuade someone to come on a ride with me. I always take the Ritars myself - not wishing to put them off ebiking for good!Regarding SLA value, it's important to realise the effect of Peukert's law. In high discharge usage as in our e-bikes, SLA batteries will only give up around half their content or a little more. This means a 12 Ah battery will only have effectively about 6 or 7 Ah in most e-bike usage, and never anywhere near the nominal 12 Ah.
Obviously this drastically changes the £/100Wh figure in the chart. For example, the ebay Ritar 12 Ah SLAs shown as £15.74 per 100Wh is in reality more like £28 to £31 per 100Wh for comparison with most bike specific lithium batteries.
There’s more I would like to say about ‘the occasional user’ but I’ll leave that for another thread. I won’t be making any further changes to the list after today.