Laptop Battery Small But good Mystery. (1 Viewer)

[Adam Sanchez]

Hey all,

Was hoping someone could shed some light on this mysterious situation for me.

I have a Dell Inspiron 8100 Laptop. I've had it since 9/2001. My original Li Ion Battery started going out about a month ago, meaning it barely holds a charge for 20 minutes now when running on it, so I bought a new battery. I got a newer model battery since they have changed in the last year and a half. I got the new 4460Mah Battery that lasts longer than my original one. The new one will last me an average of about 3 hours depending of course on what I am doing.

Here is the interesting part: My Laptop has a slot for both batteries. So just for fun I put both my old and new battery in to see how long they would last. I expected to get maybe 3:30, the time I have with each battery invidually, but instead I get about 5 hours! It seems somehow by using both I get alot more power from my old battery and the system drains them both slowly rather than one, then the other like I figured it would. So I'm getting alot more juice that I expected. I'm just wondering, is there any downside to doing this? Could using the old battery with the new one hurt it at all? I just spend $100 on the new one and just don't want to go out again soon having to get another.

Thanks for any input. This has got me quite curious.

 

[Adam Sanchez]

Anyone?

 

[Max Leung]

I think I heard of something similar on another site (probably through a google search for something unrelated).

I can only guess that the old battery, when installed by itself, would give false/incorrect current readings to the laptop, causing the laptop to think the battery is almost dead when it isn't. With the new battery installed at the same time, the laptop is probably taking the current reading from it, ignoring the old battery.

The old battery may actually be holding a good charge, just misreporting its actual capacity.

Maybe.