Ok here I go again ...
So my s85 battery has been swapped out but nothing has changed. The service centre is now saying the car needs a firmware upgrade as its on the last update in 2018.
The car is always on wifi and the SC say the update has been downloaded but the car is not giving any options to install.
- it feels like they haven't changed the battery at all when they are saying they have. (They say they replaced it for another new 85 but as far as I know they dont make them anymore)
- They had the car for 2 weeks but didnt do the upgrade, anyone else know how to make the cae upgrade?
The new battery wont charge past 96%
Please someone help ... again
I'm not sure if I can be of much practical help but here's my suggestions:
1. Document all the specific evidence you have that relates to the behaviour of your battery (max % charge, max Supercharger rate, anything else?)
2. Document repeatable tests to check if any of the above has changed following work by the SC or software updates (charge up in controlled conditions, Supercharge in controlled conditions etc.)
3. Have a look for the battery label - on my S70 this is just behind the front right wheel arch, partly obscured by some material lining the wheel arch. This will tell you what kind of battery you have (85, 75 etc.) and from the part number it may be that clever people on here can tell you if it has been changed or is an original.
4. The SC should have given you some paperwork so double check what it says they have done.
My car is on 2018.48.12.1 d6999f5. I don't see how a new software update will make any difference to some of the issues you've mentioned, particularly max Supercharger rate.
For me there are two key tests:
1. Supercharge rate. This should follow the plot shown in ABRP's excellent blog:
Tesla Battery Charging Data from 801 Cars. You need to refer to the BT85 plot. For a
fully warm battery
below 20% SOC it should charge at 118 kW. If it's an older battery that has been rapid charged more than a certain amount it will be capped to something like 90 kW. If the battery isn't fully warm, or you're sharing a charger pair, you'll get less, maybe as low as 30 kW (also make sure your charger port is dry and the SuC cable is dry and not cracked or damaged). At this time of year you may need an hour of driving to make sure the battery is fully warmed up (this is one area the latest software update might make a difference as I think cars will now pre-heat the battery if a Supercharger is a destination in the Nav).
2. kWh used on a long trip. Charge the car up to 90%+. Make a note of the state of charge immediately before setting off. Do a long drive - the more charge you use, the more accurate the reading. Don't get out of the driver's seat otherwise the trip will stop recording current energy use. The car will take account of the heater, lights etc so long as it's awake. Note the state of charge and trip stats at the end of the journey, in particular the energy used since last charge.
For example: Charge to 95% and set off immediately, drive 100+ miles without getting out of car, arrive with 40%. Trip says 39.6 kW used since last charge. So 55% used = 39.6 kW, estimated battery capacity is 39.6/0.55 = 72 kWh. ABRP says their average measured 85 capacity is 73.4 kWh for reference.
Personally I wouldn't be too hung up about only charging to 96%, that could just be a calibration error that will settle down (my car has never charged above 99% since new). The key metrics should be (a) max Supercharger charge rate of at least 90 kW and (b) estimated capacity around 70 kWh. But I'm no expert and all of the above is based on personal experience with my S70 (I don't have anything clever like a OBDII logger thingy).
HTH!
), a "there" and a "back" journey, nearly all dual carriageway, fair bit of roadworks, which helps of course, some spirited driving on the A5 which was mostly empty in North Wales 
