Hey! We can troubleshoot the computer battery not detected message safely — no risky tweaks, no “magic fix” tools. When Windows says “No battery is detected” (or the battery icon disappears), it usually falls into one of these buckets:
1) A temporary power/EC state glitch (after sleep, update, dock swap, or a hard shutdown)
2) Windows can’t see the battery via ACPI (Device Manager battery entries missing/odd)
3) The system sees the battery in BIOS/UEFI but Windows doesn’t (driver/state mismatch)
4) The charger/USB-C dock is causing confusing symptoms (e.g., “plugged in not charging” vs “battery missing”)
5) A physical connection/health issue (more common on older units, but we’ll confirm with non-invasive checks)

A few questions first so we don’t guess:
• What device is this (brand/model) and are you on Windows 11 or Windows 10?
• What exact wording do you see: “battery not detected”, “no battery is detected”, “plugged in, not charging”, or the battery icon is just gone?
• When did it start — right after an update, after using a USB-C dock/charger, after travel, or after the laptop ran to 0%?

That timeline (sleep → next day → battery not detected) often points to a “stuck” power management state rather than immediate battery failure — but we’ll verify carefully.

First, I want to separate three different situations that look similar:
• Windows can’t see the battery (ACPI/battery device missing) → “No battery is detected” or missing battery section
• Windows sees the battery but can’t charge → “plugged in, not charging” / stuck percentage
• The laptop only runs on AC → battery truly not available to the system (hardware/connection/firmware)

Quick checks (just observation):
• If you unplug the charger, does it shut off immediately or stay on for even a few seconds?
• Does the battery LED (if your model has one) do anything unusual (blinking pattern)?
• Have you used a different charger/USB-C cable recently, or is it the same original adapter?

Thanks — that’s an important clue: if it powers off instantly when unplugged, the system is behaving like it’s running on AC only.

That still doesn’t automatically mean the battery is “dead.” It can also happen if the battery isn’t being recognized at a firmware level, or if Windows is failing to load the battery interface correctly.

Let’s do a low-risk “where is the battery visible?” check. No installs, no disassembly:
1) Can you restart and enter BIOS/UEFI (just to look, not change settings)? Many laptops show a battery status/health or “AC adapter” status page.
2) In Windows, open Device Manager and expand Batteries. Do you see entries like Microsoft ACPI-Compliant Control Method Battery (or vendor battery device), or is the Batteries category missing entirely?

If you tell me what you see in BIOS vs Device Manager, we’ll know whether it’s firmware-level detection or a Windows layer issue.

You’re right to be cautious — in BIOS we’ll only observe. If a menu offers “restore defaults” or anything like that, we won’t touch it. We only want to answer one question: does the laptop itself report a battery present?

Also, Batteries missing in Device Manager is a strong indicator that Windows isn’t currently loading the battery interface at all (not just “charging problems”). That can happen after an update, after a sleep/hibernate glitch, or after certain dock/USB-C power events.

Two safe checks that are purely diagnostic and reversible:
• In Device Manager, click View → Show hidden devices and then Action → Scan for hardware changes. Sometimes the battery devices re-appear if Windows simply didn’t enumerate them on wake-up.
• If your Lenovo has a built-in keyboard shortcut or a pinhole reset (some models do), don’t use it yet — first let’s see what BIOS reports about battery presence.

When you enter BIOS/UEFI, do you see any battery info at all (percentage, “Battery Health,” or “Battery: Present/Not Present”)?

That’s a reasonable suspicion — and we can still approach it methodically without opening anything yet.

When BIOS doesn’t mention the battery and Windows has no Batteries devices, it suggests the system firmware isn’t detecting it (or it’s not reporting it). Possible causes include:
• A stuck embedded controller (EC) state (common after sleep/update)
• A battery protection state after deep discharge (if it recently hit 0%)
• A connection/pack issue (less common suddenly, but possible)

Before we assume hardware, I want one timeline detail that changes how we interpret risk:
• Did the laptop ever run down to 0% recently or shut off from low battery?
• Any recent knocks, pressure on the bottom case, or travel in a backpack?
• Do you ever charge through USB-C or only the standard Lenovo charger?

Makes sense — we’ll stay within warranty-safe territory. Since you mentioned a past deep discharge, one thing that can happen is the power controller/EC ends up in a confused state after sleep or updates.

Here are the next steps I’d use purely for diagnosis (not “repair”), and they don’t require opening the laptop:
• Confirm whether the battery ever appears in Windows after a full shutdown (not restart) vs after sleep/hibernate — that helps identify a wake-state issue.
• Generate a Windows battery report (if Windows can see a battery, it will show; if it can’t, the report often confirms “no battery present”).
• Check Lenovo/Vendor utility (if already installed) only to read status — not to update firmware right now.

If the battery still isn’t detected in BIOS after those checks, that’s useful evidence for support: it suggests the issue is below Windows (firmware detection or hardware path), which is exactly what warranty teams need to know.

If you tell me whether the laptop behaves differently after a full shutdown versus after sleep, we can narrow this to “state glitch” vs “consistent non-detection” without doing anything invasive.