Any D620 owners w/second battery?

I bought a used D620 laptop a while ago. It seems the best I can do is 2 hrs of battery life before it warns me its going into hibernation. This laptop is supposed to take a second battery and I found where it goes. (Remove the DVD drive)

Does anyone actually use the second battery? How much extra time do you get? Anyplace to get them other than Dell?(cheep)

 

I have a D820 with a second battery. I bought the battery from Black Cat PCs in the UK.

I used to get (I use my M6400 now, my wife has the D820) around 6 hours when using both batteries.

M

 

I have a D630 w/ a secondary battery. The 2nd battery drains first to 10 percent then it kicks over to the primary battery. Depending on which graphics chipset you have, and also screen brightness you should be getting a bit more that 2 hrs. The battery itself maybe worn, and a new replacement may improve your battery life.

Also another option is a 9 cell primary battery that extends out the front of the machine giving it a quasi wristrest. As far as run time when both my 9 cell and media battery were new I would get about 10 hours give or take. I get about 7 or so now between the two in my d630 w/ intel graphics, intel wifi 5300, t9500, and medium brightness.

 

I got about 5-6 hours with my 9 cell in power saver w/ Ambient Light Sensor enabled. Now I get about 4. Still, not too shabby.

 

The secondary battery has a capacity of 48WHr. You can calculate how much more you're going to get out of it if you know the current full charged capacity of your current battery You can get that figure from RMClock or some other battery utility.

For example, if you still had full charge on say a 6-Cell, that's 56WHr. To get two hours on 56WHr, means that on a combined 56WHr + 48WHr, you'll get 2/56 = 3.71/(56 + 48).