Hi stevengillies,
Thank you for reaching Microsoft Community. I'm sorry to hear about the battery issues you are having with your Surface Go.
Lithium-ion batteries are the most common type of battery used in today’s portable devices. These batteries charge quickly, discharge deeply at a steady rate, and have high energy density that allows for small cell sizes. Like all batteries, lithium-ion cells are consumables that age and deteriorate over time and with usage. When batteries experience excessive deterioration, you may see severe battery life reductions. See: Caring for your Surface battery (microsoft.com).
Please try running these steps first on your Surface Go then see if the behavior improves:
1: Run Surface Diagnostic Toolkit
See: Fix common Surface problems using the Surface Diagnostic Toolkit (microsoft.com)
2: Check for Windows Update
Go to Windows Settings > Update & Security and select Check for updates
Make sure all updates need are installed including Optional updates
3: Update drivers and firmware
Check what is the current OS Build of your Windows version by going to Settings > System > About.
Go to Download driver and firmware for Surface, choose Surface Go
Then click the link next to Surface Go then click Download on the next page.
Choose the .msi file that matches your current OS Build and click Next.
After downloading, run and install the .msi then Restart.
4: Run System File Checker Tool
See: Using System File Checker in Windows (microsoft.com)
If still the issue persist, please try to generate a battery report of the device by following these steps:
Open Command Prompt as Admin
Click Yes on the UAC prompt
Type this command below and hit Enter
powercfg /batteryreport
Open File Explorer and access the html file location given in the Command Prompt
I will send you a private message where you can send the battery report generated as an attachment.
Kind regards,
Marrion