Hi, Folks, Long-time lurker, writing to thank the forum and and offer some info. I have an iZip Dash E3 2015. I ride about 11-12 miles/day, commute includes long uphill to work, downhill home. Original battery lost range, especially in last 6 months, (caused a challenge for adding more miles to the commute, like trip to store or ride kids to school) and there was back order for replacement. This thread and some others pointed me to LunaCycle options, purchased and installed a Dolphin 13.5 Ahr battery as replacement. LunaCycle is very DIY, no phone number to call, but responsive by email. The Dolphin is old design, but wanted external switch without removing battery from bike. The mounting bracket was not a perfect fit, had to drill a hole (like GadgetGuy), also reamed out back of bracket with Dremel tool to make room for the "mounting nubs" on the downtube. Not too hard. Used longer bolts, added some 1/8" rubber sheet stock below bracket, so I had something to tighten against with the bolts. The wiring from bike was 2xRed (together: big, small), 2xBlack (together: big, small), plus white and blue in middle. Original battery had four terminals. I disassembled both original bracket and battery to see how Blue and White were set up, these come from the BMS. New battery did not have this, so did not try to connect these - just disables battery status/range indicator on display (like GadgetGuy said). Soldered up the wires: 2xRed (together: big, small) to red on new battery bracket, 2xBlack (together: big, small) to black on bracket, protected with heat shrink, etc. Sealed up blue/white...in case I figure out how to connect these later. Added velcro strap to help hold battery on bracket/tube. Batt is a bit heavier than original, but narrower profile. It works, I like the external battery on/off button. Will see how it performs and will post an update later. This forum was helpful in selecting the Dash, which I like...overall. Smooth ride, lots of grunt from CurrieTech motor, etc. Upgraded disk brakes this year to double caliper, better stopping power. Should be good for another few years, with about 50% more capacity on the battery, less range anxiety. Very helpful to have this forum, appreciate people taking time to post.