I have a Dell Latitude 5500 laptop. With the power cord connected, it boots and runs fine. Once booted, I can disconnect the power cord and run from the battery for a few hours. No problem.
However, I cannot boot the machine when running on the battery, even when the battery is fully charged. I get the kernel selection screen, but the encrypted drive password never comes up. I just get a blank screen.
If I connect the power cord, it boots just fine. If I disconnect the power cord while it is running, the system runs as expected on the battery.
So, my battery is fine, and I can run with the battery as expected. However, I cannot boot when on battery power.
When I first got the laptop, it had Windows installed. When Windows was installed, it booted on the battery without a problem.
Problem solved. My system had BIOS version 1.7.4 installed. I updated it to 1.20.0, and everything works! No need for any of the other workarounds described elsewhere.
Can you recall if you ever have a scenario where the system wouldn’t physically turn on unless the power cord was plugged in? My 5500 wouldn’t randomly turn on at all (despite fully charge battery) if it was left for an extended period (1-2 weeks) - you might think it was the battery but nope! if i plugged in charger, then turned on, suddenly it came to life and if then charger was then removed, i’d boot to windows and see battery was still 95%
This issue was present since the day i bought it in 2020. I’d tried resetting CMOS (taking battery out etc.) to no avail. shipped with 1.9.1 BIOS. Tried updating to 1.15 last year, and only this year had i thought might be worth trying a new BIOS again to see if the issue was fixed. About 2 months ago, I updated to the latest (at the time) 1.23 and I have not had a reoccurrence.