S800G Mod

Eventually...

Eventually I would like to slowly remove the structure and replace it with lightweight protoboards allowing for on-board computation. Using an ATMEGA328, a gyro, two IR sensors and an extended battery pack, I hope to build an autonomous wall following copter. Basic algorithms should allow it to navigate slowly and with a simple state machine. However a more advanced application will allow for more aggressive motion with the possibility of racing and obstacle courses.

Introduction:

I am working to improve the battery life and in turn flight time of my S800G radio controlled helicopter. If you remove the front covering you will see that the battery is a 3.7V 150mAh Li-ion battery.

With any experience in hobby electronics you will know that most Li-ion batteries have a 3.7V nominal voltage. So after checking a few old cell phones I found some replacement batteries. Originally I tried an old HTC 1230mAh. Before connecting the power terminals I attempted to mount it in multiple positions (to maintain the same center of gravity). However, it was easy to see that the battery simple weighted too much and would not let the copter take off. I have a few smaller 600mAh and 800mAh batteries which I will test soon.

Connecting The Extended Battery:

It is as simple as connecting the positive to the positive (red) and ground to the ground (black) of each battery. You will be able to use the factory charger since the cell phone batteries are designed to charge much faster. Note that charging will take a lot longer than usual. Be careful not to short the batteries at any time as this can damage the batteries or charging circuitry.

Remember when mounting the batter that you still need to access the power switch on the bottom of the  helicopter body. I used a piece of duct tape to act as a hinge and a rubber band to hold the batter secure to the skids during testing.

If you have another small battery you can also attempt to mount it inside the tail supports. This is untested but provides an easy to mount location for testing.

Conclusions:

I have not found a good location to mount the extra battery, since I am still tested lower mass batteries. Currently I suggest remove the tail and mounting the battery such that it maintains the center of gravity. This will remove un-used mass and provide extra flying time to an already great toy.