I already have a compact battery jump starter so I don't need another device to charge.

Last year I found this on the one on the shelf in the hardware/automobile isle of my local grocery store: Victor Bell Automotive Bellaire 500 - TIRE INFLATOR ($25 at Amazon.) The pump is VERY compact and uses very little current and doesn't blow the 5AMP aux fuse. It takes a while but it works. I added a 12V outlet in the left saddle bag connected to the AUX posts in the fuse panel. The 12VDC connection is long enough to easily reach the front tire.