Im sorry I dont have anything super helpful at this time but I would like to add a few things. First, could you fill me in on what the "SP" mod is?
Regarding your battery counter situation, have you ever seen the counters reporting above 70? Is the 150 number a guesstimate based on your experience, or have you been keeping a rough tally, apart from the software counter?
I only ask because I found out awhile back that the software counter keeps count of how many 0-100% cycles each of your packs have had.
So, if youve flown 2 completely separate flights, discharging full 100% down to halfway, 50%, then after, you fully charged it both times, I believe the software will only report 1 charge cycle even though you put on charger twice. (Im going off others on the forum, and not direct knowledge, so this may be incorrect? It was awhile ago.)
Anyway, worth mentioning, although if your modding your AC for non-DJI packs then thats a more likely candidate for your counters acting up.
Probably couldve said all this in many less words, but thats a failing of mine.
Good luck