Ubuntu 18.04 Won't Boot on Battery Power

Older Acer Aspire laptop with i3 processor. Ubuntu loads fine when plugged in wall, but won't boot with only battery power. I see the Acer splash with bios information, but it turns off before ever seeing the purple Ubuntu boot up screen. Had no problems with Ubuntu 16.x. Laptop recently got new battery.

Any assistance appreciated.

Solution

This link worked for my HP laptop.

1) Modify the GRUB_CMDLINE_LINUX_DEFAULT kernel variable in /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash dis_ucode_ldr"

2) $ sudo update-grub

3) Reboot.

dis_ucode_ldr stands for "disable microcode loader"