Unsolved
1 Rookie
•
3 Posts
0
44
March 8th, 2026 21:41
How can I disable the automatic startup of a Vostro 3578 laptop when the BIOS battery is discharged?
Hello
What can be done to prevent a Dell Vostro 3578 laptop from automatically turning on when the power adapter is plugged in, when there is no main battery installed and the BIOS backup battery is not working?
In this laptop, the main battery has been removed, so it operates only on AC power.
In addition, the BIOS reports a problem with the date and time, which suggests that the BIOS backup battery is depleted. This is also indicated by the incorrect system date and time.
When the power adapter is plugged into the laptop — even before pressing the power button — the laptop starts up automatically. A screen appears with a message about the date and time problem, the laptop heats up, and the fan runs at fairly high speed, but essentially nothing else happens.
Best regards.
DELL-Daniel V
Community Manager
•
219 Posts
0
March 12th, 2026 15:55
Click on this link here to view the service manual for CMOS removal steps. As to the system powering on when AC power is connected and the battery is disconnected, this is by design. If a unit does not have a battery installed, then it will power on once an AC adapter is attached. The CMOS battery failing should be seen an independent failure and just needs to be replaced so that you can set the time and day. You would need to install a full sized battery in order for the AC adapter to not trigger the unit to power on.
(edited)
Theofilos
1 Rookie
•
3 Posts
0
March 12th, 2026 17:13
Removing the battery is not simple — you have to disassemble half of the laptop.
You are not right that if a laptop has no battery, it will turn on when you connect the power cable.
That does not normally happen.
When I replaced the CMOS battery, the laptop no longer turns on when the power cable is connected, and the main battery is still not installed.
So this is clearly a problem related to a depleted CMOS battery. If the CMOS battery does not work and there is no main battery, the laptop turns on when the power cable is connected.
So the question remains: what can be done to prevent this from happening?
ejn63
10 Elder
•
30.8K Posts
0
March 13th, 2026 14:14
There isn't going to be an option to do what you want short of rewriting the system firmware.
It sounds like there's an issue with the mainboard -- which at about $40-50 is cheaper than replacing the main battery.
Theofilos
1 Rookie
•
3 Posts
0
March 13th, 2026 14:24
Why replace the main battery?
It’s perfectly fine.
I only removed it because when I work on the power cable, there is no point in keeping it installed.
The problem is not the battery, but the laptop turning on when the power is connected — without pressing the power button — when the CMOS battery is depleted.
When the CMOS battery is good, everything works correctly.
ejn63
10 Elder
•
30.8K Posts
0
March 13th, 2026 15:19
There is a point to having a CMOS and/or main battery installed -- so the system will function normally when you plug in AC power.
Unless you're wiling to work around the fact that it powers up without the power button by rewriting the firmware, keep at least the CMOS battery installed.