I'm experiencing something similar to the original post, with some noteworthy differences.
23 RT S2S, purchased in Oct 2023. Drove it about 250 miles before winterizing. Kept it on the Optimate Maintainer through winter.
My buddy and I installed four front end light kits in Dec. We used the "Plug & Play" harness from Lamonster for the fender and mirror turns signal kits, while the Bright Rider frunk light and Double-AA lights were powered up from the Aux port under the starboard side body panel.
https://www.spyderlovers.com/forums...4-What-did-you-do-to-your-Spyder-today/page71 (post 1774)
I installed the light kit on the upper storage trunk last month, also using the supplied "Plug & Play".
On Tuesday of this week I pulled the Sypder out of the corner, did a T-CLOC inspection, adjusted air pressures, removed the rag from the exhaust pipes, geared up and started it up for the first ride of the year. It cranked much slower than I expected after having it on the maintainer for most of the off season, but it fired up and ran very well. I put probably 50 miles or so before returning home with intensions of having it ready for my wife to ride when she got home from work. I shut it down, then about 10 minutes later went to fire it back up and it barely turned, over acting very much like a dead battery and did not start. I did not see any codes displayed during my attempts to restart the engine.
I pulled the Haijiu battery out and put it on my full size charger, which showed that it had 100% charge and 13.5 volts. The next morning I came onto the forum to look for posts with similar experiences, and found numerous mentions of low quality batteries. I came to the conclusion that this must be my problem. Since we have plans to ride the bike on Saturday I was eager to get this resolved ASAP, so I went to Battery Plus and picked up a new battery, grabbing the only one they had in the store that matched the size and specs. I'm sure it's not a high quality replacement, but I bought it and put it on the maintainer overnight then checked it after work today. It showed 100% charge, 13.6 Volts. I installed it, tried the start the engine and got the exact same results as the day before. I mean the EXACT same. Verrrry slow crank. Still didn't see any codes.
What are the damn chances that two fully charged batteries would produce the exact same results. I'd think that if this problem was in fact battery related then the engine rotation would surely be slightly different after installing the 2nd battery. So frustrating. I called the dealer, the next open timeslot they have isn't until April 3rd and I've locked that down, but sure would like to figure this out way before then. Anyone have ideas?