"Battery not detected" and "plugged in, not charging"

My battery says "1% plugged in, not charging". I ordered a new battery, installed today got msg saying "battery not detected", i shut it down, took battery out, replaced, restarted (several time), same msg. I visited many forums and read many threads on both of these issues. Apparently both of these issues are common with Dell, but the general consensus of the community is that i need to do a Bios update..So i downloaded the driver for the Bios update and attempted to install is, but got a massage that the adapter AND the battery must both be plugged in, in order to do the update..well..how can i "plug the battery in" when my pc is unable to detect the battery??!!!
So i shut it down for like the 10th time this evening..took battery out and replaced it with the old battery..the one with 1% charge, but at least my pc is able to detect this one. I go back to the Bios update download, attempt to run it and get a msg saying battery must be 10% or higher to run the update **sigh** really frustrated now. I have seen people say its a loose connection and i should tap it near the motherboard...this did nothing. I jiggled adapter cord, nothing, i cleaned the connectors on the both batteries, nothing. I ran a diagnostic test thru dell.com on the battery and it came up as PASSED...lol..seriously?? I ran troubleshooting..nothing found.. I am at my wits end...help???