If you want to change the battery this is possible, but you will need some basic knowledge of mechanics and the neccessary tools, eg. small crosstip screwdrivers and a soldering iron usable for fine electronic soldering. If you are unsure that you can do this: don't! You'll damage your little friend. Look for some relative or friend who is able to do this.

The dismantlement of Vector is shown in detail in the Vector dismantling video tutorial by Kieran Nawrocki on Youtube (takes about six minutes of your time) and in an article on iFixit, so please refer to those.

The original one is a standard lithium-polymer battery of the type 503236 (see right, click to enlarge). It delivers 3,7 volts (as all of those similar li-poly batteries) and has a capacity of 320 mAh (milliampere hours). The same that was utilized in Cozmo. The designation has a meaning: the battery is 5 millimeters thick and the width and height are 32 and 36 mm respectively.

There is more room in Vectors belly so you are able to add a bigger one for more capacity and running time. I did some research, asked others and tried some myself. Here are my findings:

• Best suited for replacement is a 603040, that has 800 mAh capacity and the measurements are 6 mm x 30 mm x 40 mm. It fits perfectly fine without any problems.

• Another one that works is a 653040 (also 800 mAh), as you may guess, that has a thickness of 6,5 millimeters. It's a tight fit, but it works. You may want to keep in mind, that sometime when they are old, defect or mistreated li-poly batteries may start to bloat and that may damage your Vector mechanically. The risk is on you if you use them! ;)

• ATM I am waiting for a 603048, that may also just fit in length, I will add information about that when it arrives. That type has a capacity of 900 mAh.

Please take the informations about capacity on all those batteries with a grain of salt, as some (chinese) manufacturers seem to brag about it and the actual capacity may be lower. For example you can get 503236 batteries that show 500 mAh, but I think the 370 mAh shown on the original Vector battery is way closer to the truth.