Great question. I wrote a battery charging article a while back that touches on this, but didn’t include anything about storage longevity. I think most people will degrade their scooter battery pack via cycling rather than just storing (unless stored improperly).
I looked into your question and basically the best info I could find was in this article that talks about storage.
The figure they give for lithium ion batteries is 10 years, with minimal degradation, if stored properly at about 50% charge (individual cell voltage around 3.8 V).
Basically lithium ion batteries seem to have amazing shelf life, so I’m not sure 3 years is the right way to think about it. I think more about it in terms of # of cycles or possibly miles.
Not sure which LG cells are used in your OXO, but the LG MJ1, which I’ve seen used in some other scooters, were tested by Battery Bro and got they 400 cycle life time, going from 2.5 V to 4.2 V.
The 2.5 V cut off from this test is significantly below the 3 V cutoff that most scooters are using, which already makes it a pretty conservative measurement.
Our performance tests of the OXO gave us 36 mi / 58 km of real-world range, so I’d very conservatively estimate 400 cycles * 36 mi = 14,400 mi / 23,175 km of life on your battery pack or $1500 / 14,400 mi =$ 0.10/mile operating cost.
More realistically, if you are operating those batteries from 3 V to 4.2 V I’d expect to see closer to 500 full cycles.
If you really go full battery nanny and operated in the optimum 30% to 80% range, you might get 3X to 4X more cycles (though each cycle will only be 50% of capacity), but will still net you more miles overall.