Determine if the Dell Latitude D810 battery
is defective. While less than 1 percent of batteries are defective, the possibility is still there. If the battery is new and only charges some of the way, it may just require a BIOS update to charge fully. New batteries that refuse to charge at all may be defective. Purchase a new laptop battery to replace the defective one.
Test the laptop power adapter to see if it's faulty. Run the laptop directly from the laptop power adapter and without the battery. If the laptop does not work with the adapter plugged in, the adapter is dead and you will need to replace it. The laptop battery may refuse to charge if the adapter is faulty. Charge the battery with the laptop turned off.
Insert the laptop battery into another laptop to test it. If the laptop battery charges in another laptop, the laptop's motherboard may be bad. Replacing a motherboard in a computer can be very expensive. If the cost to fix the computer is not worth the cost of replacing the motherboard, consider purchasing a new laptop.
Reinstall the battery to ensure all connectors latch properly. The latch mechanism that holds the laptop battery should click into place. If the latch does not close, remove the battery and examine the compartment for signs of damage.
Troubleshoot the BIOS to determine if there is a hardware problem. Turn on the laptop and immediately enter BIOS setup by holding down the "Del" and "F1" or "F2" keys, depending on the make and model of the laptop. When the BIOS screen appears, see how long it takes for the battery to charge down. If the battery does not last as long as the BIOS setup, a hardware failure may be the problem.