Where is the battery placed in a compaq presario2100

This is one place of many.
http://www.amazon.com/Battery-Compaq-Pavilion-DV6-2155DX-Notebook/dp/B0043BLTC0

This isn't your model , but this may a place to start: http://www.youtube.com/watch?v=aZfbH6-slXE ALSO, take a look at HP/Compaq Support: http://h10025.www1.hp.com/ewfrf/wc/product?cc=us&lc=en&dlc=en&product=428257

It can be due to a fault in the retaining lock on the battery , if the contacts of the battery has come out or if the battery connectors on the main mother board is weak, loose or drysoldered.
So check on the battery fitment, if this does not stay in place use a cardboard to WEDGE and tigthen it AGAINST the terminals -- to give the tight contact.
if this wont improve then check on the mother board and solder.

You can by a new or used battery from several places on line, it costs around 60 - 80$. I have included a link to reputable seller below.

http://www.vpgames.com/p-18561-hp-compaq-evo-n180-presario-2700-233336-001-compatible-battery.aspx?utm_source=Google&utm_medium=Froogle&utm_campaign=CET-2C124Q25

Hello sexychispa. To remove the battery of your Compaq Presario v3000, start by turning the laptop over so that the bottom side is viewable. Look for a rounded slot in the bottom that has a sliding tab within. This is the battery release latch. Using your finger, slide the latch and hold to release the battery. With your free hand, assist the battery out of its compartment and allow the release latch to slide back into place.
For more information on the process, be sure to view this link to HP's guide to removing batteries from Compaq laptops.
Hope this helped!

1. Place your laptop in such a way that the rear part is exposed.
2. Unscrew the locks of the covers to remove the covers and eventually expose your laptop's motherboard.
3. The battery is situated in the motherboard and it looks like a battery of a watch.
4. Remove the said battery and find a replacement of exactly the same kind and specification like 3.0V or something that is printed in the battery itself.
5. Then place the new battery and close the covers.
   

I have bought a couple of batteries from them before. They work just make sure that the voltage of the battery. (10.8v) matches the voltage on your battery. Also make sure that the mah 6600mah is greater or the same as the battery that you have. The mah is the mili ampers per hour (in other words the fuel) the bigger the mah the longer your battery will run. I also find ebay a great place to buy hp batterys from. Just make sure that they are oem hp and not a generic knock off and you will be fine and use the same rules from above. and also make sure they will fit your model number. I hope this helps
thanks
Steven.

remove your battery then place new battery

Hello!

You did not reply i have no idea about your problem.

melnavz

is that an Microsoft Official Service Pack? anyways. Try using a System Restore and choose a restore point on your problem.