So this seems like a bug thats been a thing for a while (I think from around when you were rebalancing some upgrades) but the extra battery charges upgrade is bugged in a really annoying way. When you have it on and have either of the sex acts that use battery it can sometimes use 2 charges, this happens even if you equip this battery upgrade for first time (so you have 7/10 in case of first upgrade). I believe this was allready an issue when you originaly changed the upgrades to be +2 and +3 respectively (but during that I assumed it was just counter visualy breaking as it still displayed regulare +3 and +4 on ui).