Dell B610 Battery Not Charging

I am the proud owner of two Dell B610's now with the same problem. A year ago, I was not paying attention and my laptop was running on battery only and it went all the way down to 2 or 4% when the battery icon turned bright orange. I plugged it in and it wouldn't charge up again but worked perfectly. So I bought a brand new battery and it still wouldn't charge.

I then bought a second one, swapped the harddrive and memory chip and with the exception for intermittent messages from Microsoft that the laptop had bootleg software on it (due to the swap), it worked perfectly. Yesterday. my wife unplugged my laptop to plug in the vacumm cleaner and the same thing now happens to the second Dell B610. The battery says 0% battery power, it's plugged in and now this one won't charge up either.

What do I need to do to get these two laptops charging and working coreectly again without being plugged in. The batteries are fine.

Thanks!