How? On the old bike the stem was long enough to sling the battery underneath; new one isn't. Is it as simple as just velcroing to the top tube (which looks awkward)? Any pics of better options?
Just velcro it to the top tube, sling it underneath, it's not been a problem.
Mine fits under the handlebars
is this the battery that clips onto the faceplate?
If so, just invert the faceplate and clip it on the top.
If not, just velcro it wherever it fits.
Not a Hope battery, but I attach mine to the underside of bars in a battery pouch with velco, either side of the stem, as the light has an offset mount this works great.
I zip tie some old inner tube to my top tube and fuse the velcro strap that came with the battery. This stops the better from moving about too much and does not scratch the frame either. Although I have been thinking about getting a longer cable and just having the battery in my camel bak.