Could do with another battery for my Volt Alpine -the original one where the battery slides down behind the seat tube - Volt want almost £600 for one but I see a similar 15Ah silverfish battery with 4 ports on eBay for about a quarter of that !! Size wise it seems to be the same but not sure if it would fit the slide in rail etc - anyone any experience in using one of these battery with a Volt bike ?? Thanks