The old lead acid battery was not doing well this spring. Several failure to starts. After charging up, the old battery read 12.8 at its highest. Still not doing well and so I have a good excuse to buy fancy bike stuff.
Chose the Battery Tender lithium battery. Staff at Battery Tender told me that charging with my Battery Tender Jr (for all batteries) would be fine. Chose the 120 as it was smaller. Cost $84 on Amazon. The 240 specs said it was 5.27" and my battery box sure seems to be 5" wide otherwise I may have gone next size up. Here is a comparison of size. The battery is terribly light.
The lithium came out of the box reading 13. After charge up here.
I used a couple of bits of pipe insulation to add to the foam inserts that came with the battery. I used all of this fill material and still the battery feels as if it may move. I'll keep an eye on this.