I have the powershot SD3500IS abd it says i need to change the battery pack what is that and how can i fix it also if i dont have a charer can i charge it with the usb ?

CANON PowerShot G9 Battery ? If there is lens error you'd better find the professionals to fix it . Or if you want to change a new one and don't mind too much about this camera, you can read this article about lens error and to see if anything help

Hi;that is look like thats is your battery pack
;/try removed the battery out and used the power pack to power the camera, and lets charge the battery pack for almost 10 -12 hrs that way you willbe sure if its the battery or the camera are the problem...
Hope that help you...

This model is the IXUS 210 IS in Europe. The Spanish version of the manual is available here.

You need to learn tips for careing your camera battery pack,and you'd better to buy a new canon nb-2lh battery in a camera battery shop.

All the battery have a life time fixed working hours. Your battery is charged but he complete is working time. Thats why these msg will come. Dont warry use the battery when you see the power going down after a while of charging then change the battery and buy new 1. Good luck.
Thanks, i am waiting for your feed back & if you satisfied then thumps me please.

Take a picture with the new battery pack. Is the picture also blank? Are the menu selections still visible in the LCD? Have you tried pressing the DISP button on the back, but the screen still remains blank?

If the answer is yes to these three questions, this sounds like it might be a defective CCD imager. If so, Canon should fix this for you for free, including free shipping both ways. This is regardless of your camera's warranty status. Please check this link for more info.

Applicable cameras include:
A40, A60, A70, A75, A80, A85, A95, A300, A310, S1 IS, S60, S200, S230, S330, S400, S410, S500, SD100, SD110, IXUS V2/300/400/430/500, IXY Digital 30/30a/200a/300a/D320/400/ 450/500

cudgegong said in another forum:

To resolve the annoying "change the batteries" problem. Goto menu, choose yellow menu, select
file No. reset to ON. Turn camera off and back on.

Voila fixed.

have same problem with canon sd10. bought new battery and new charger, THIS IS A CANON HARDWARE PROBLEM I assure you

The battery packs in these units dont have a very long "shelf life" meaning when you charge the battery you need to use it within a few days or it will loose charge. Have you tried a fresh charged battery? They are very power hungry devices and the more advanced they get the more power they need. How old is this unit? how many charges have you put on the pack? it may be time for a second pack. An emergency backup pack good power is key nowdays.