To make my miniature lowrider models perform the best they can I use modern day technology in the form of rechargeable Lithium Ion Polymer batteries. LiPo batteries, as they are called, are rated 3.6 volt and have the advantage of being small, somewhat flexible but still containing quite a lot of milliamps (mAh) considering the size. They also hold their energy for quite a long time compared to standard NiMH rechargeable batteries. The discharge rate is quite high meaning that they can deliver a lot of power to the motors.

 

They come in sizes starting at 10X12mm having 70mAh which are perfect for powering micro RC cars, LED and in my case Colorbars. The 850mAh on the right is perfect for providing juice for the 1/25 Cadillac lowrider I'm creating. I get my LiPo batteries from Hobbyking.com as they are very low priced and the quality is excellent.



To charge LiPo batteries you need a special charger and since I have a variety of LiPo batteries I use a charger that chargers at different rates to make sure the batteries won't damage or even worse explode.

In the picture you see the bare PCB charger with jumpers and above the boxed version I created using that same PCB. I swapped the jumpers for dip switches to set the charge rate for the different batteries I'm using. The smaller the battery the lower the charging rate. This charger I bought from Sol-Expert in Germany but you can also find some on Ebay.



Here's an example of a very small 70mAh LiPo battery which I accidentally overcharged. You can see that the battery is inflated and looks like a balloon. Charging it any longer using too much amps it will eventually explode. As long as you set the right charging rate you'll be fine. 
LiPo batteries don't like to be drained/ discharged all the way to let's say 1V. When the voltage drops below 3V they need to be charged. I usually notice it when the model starting to move slower and slower than it's time to charge the battery.



I really like these type of batteries they are easy to use and you can easily fit two to three batteries inside the trunk of your model lowrider. Charging the batteries takes aprox. 1 to 1.5 hours depending on the batteries capacity. For RC lowrider models that can cruise and dance I use one 850mAh battery, for hopping I add an extra battery. The provide 3.6V and 20C discharge rate is enough to make your model go back bumper.
If you have any questions on the use of LiPo batteries feel free to contact me.