My Dell Latitude D630 will boot from the AC adapter, but not the battery. I've replaced the battery, tried booting with only one RAM card, etc. etc. I can't understand why, as my BIOS says the battery is fully charged. Windows does as well. It's not an OS problem, as I repartition my disk and install Linux at times. Any ideas? Thanks in advance.
If replacing the battery does not solve the problem, the problem is confined to the portable (you could try replacing the AC adapter too, but that seems highly unlikely)
I'd put my money on a defective connector inside the laptop, that's either completely broken or that shorts out when a battery is connected.