If your car stops charging at 80% or another level below full, the car's own charge limit is the most likely reason. Work through these checks.
1. Check the charge limit in your car
The charge limit set in the car or in its brand app always wins. Smart charging cannot charge beyond it. Raise the limit in the car or its brand app if you want more.
2. Check your maximum price
If you set a maximum price and prices stayed above it, smart charging stops on purpose, even before the car is full. Raise or remove the limit in the app. See Smart Charging Settings Explained.
3. Check your ready-by time
If you plugged in late and the ready-by time is early, there may not have been enough hours to finish charging.
4. Brand-specific checks
BMW and MINI
Set a target charge level in the My BMW or MINI app. The car stops charging at that level. See BMW & MINI Smart Charging Setup.
Mercedes-Benz
On the EQA, EQB and EQC, stopping charging can reset the Home charge limit to 50%. If your car stopped at 50%, check the charge limit of the Home charging program in the Mercedes app and set it back. See Mercedes-Benz Smart Charging Setup.
Tesla
Check the charge limit in the Tesla app.
Still not working?
Contact the support team of your app. If your app comes from your energy supplier, that is your energy supplier's customer service. Tell them your car brand and model, when it happened, and the charge limit set in your car. A screenshot of the app helps.