You can go into the VCDS battery module and it’ll give you a “percentage” figure of total battery life as in what sort of overall state/health it’s in, not how much voltage is left. It’s really a guesstimate on the BMS’s part but if you’re having strange issues, always good to start there. It can show you a number of other indicators which can help diagnose a bad battery but a load test is always the best way. Guessing the alternator was probably kicking out fairly high voltage levels on deceleration which necessitated the additional rpm. If you have that, the a/c on, etc…a higher idle may be necessary.
I was logging voltage output from the alternator and its almost all done on deceleration so they can call it regenerative braking. It’s using the alternator drag to help stop the car. Probably worth a gallon per mile.
The trans cooler is obviously a very good idea moving forward. I do have one in stock
And take a look at the Antigravity batteries. For the RS5, the 60Ah H6 or H7 will work best with the BMS. The 40Ah will work but you’ll need to unplug the BMS which takes all of two seconds. If you’re overseas, best to get it from a local distributor or at least check with them. It’s a pain for me to send AG batteries overseas, takes an extra week as I have to send AG a physical check which is just weird. I’ve shipped quite a few to the Middle East at this point as they have no dealer there.