I need science fair project ideas! please help me!?

Batteries are always good. The effect of refrigeration on life. Which brand lasts the logest in an application.

If you want to get more scientific, you could study the chemistry of the batterie and talk about the things that gain and lose electrons in the various types of batteries on the market right now.

There is a lady in Australia who recently patented a new battery that uses Vanadium for both sides of the battery. Research it and discuss how this battery overcomes the problems and limitations of the standard lead acid batteries that are used for solar energy storage and how the vanadium redox battery would be better. If you can lay your hands on the euipment and the chemicals, you could build a lab battery using the vanadium and take some measurements, then charge and discharge it many times and see how the properties change compared to the charge discharge pattern of lead acid.

Can you tell that I like the Vanadium redox battery as a solution for people who are generating their own electricity and need to store it? Lead acid is what they can buy, so that is what they use and the batteries wear out after a few years. I contend that a Vanadium Redox battery would last forever and that it can be built by just about anybody.