I carry one as well. It worked perfectly the first time I had a dead battery after leaving the car for 6 months without a battery maintainer. The second time, after being away from the car unexpectedly for 5 weeks, the fully charged jump pack would not power up the car. That was near the 4 year mark, and having had a dead battery twice, I opted to go get a new one rather than try to revive the old one.
Mine is at 5.5 years so far. I had an oil change a couple of weeks ago, and they told me it was at 230 cranking amps and that they recommended replacing it. I think I'll wait until it fails the first time (jump pack in trunk), then buy a replacement at costco.
Mine also is at 5 years, and I have a jump pack at-the-ready. Like you, I'm waiting for that first failure.
On amazon you can also get one that does USB powerbank-OBD port. Likely getting a Honda battery myself since the warranty is so good and the cost is ~the same as Costco.
Thanks for the detail. I assumed that the car would continue to start even with the 12V battery failure since the other poster said that the 12V is not used for cold cranking. From the other posts, it appears that the 12V jumpstart may or may not work. I will get it tested again at Sams since I am at the 5 year mark as well.