Hey there, sorry to hear your T470's throwing this frustrating battery issue at you—let me walk you through what's going on and whether it's safe to charge it.

First off: it is completely safe to charge your laptop right now, and this won't damage your battery further. Here's why and what you should do next:

• When you let the battery discharge completely, it can enter a deep-discharge state. The "Critical low battery" message is just the system's way of saying it doesn't have enough juice even to boot up temporarily. Thinkpad's built-in Battery Management System (BMS) is designed to prevent overcharging or damage from this kind of scenario, so plugging in the charger is exactly what you need to do.
• Leave the charger connected and let the laptop sit undisturbed for at least 30 minutes to an hour. Don't keep pressing the power button repeatedly during this time—deeply discharged batteries need a little time to build up enough charge to trigger the boot process.
• If after an hour it still won't turn on, try resetting the Embedded Controller (EC) or BIOS, which is a common fix for Thinkpad sleep/wake and battery glitches:
  1. Unplug the charger and remove both the internal and external batteries (since the T470 has both removable and built-in options, you'll need to access the internal one via the bottom panel if it's not already out).
  2. Hold down the power button for 30 seconds to drain any residual power.
  3. Reinstall the batteries, plug in the charger, and try turning it on again.
• If this happens frequently, you might want to check your battery's health. On Windows, you can run the command powercfg /batteryreport in Command Prompt to generate a detailed report showing cycle count, current capacity, and overall health.

Chances are, letting it charge for a while will get it back up and running. Don't stress too much about damaging the battery—Thinkpads are built with pretty robust battery protection!

备注：内容来源于stack exchange，提问作者Călburean Laura-Ioana