I'm working on a school group project which involves setting up a remote controlled car with a BeagleBone, webcam, WiFi module and a powered usb hub.
To handle the mechanical side, we bought a cheap car from Walmart and hacked it. It came with a battery compartment that holds 5 AA batteries that the motors run off of (at about 2 amps each. I think one measured 2.5). With Alkaline batteries, that gives us 7.5 volts at full charge. With rechargeable batteries (what we hope to use in the end), that is 6 volts. That's fine for the motors, but the issue I'm running into is the BeagleBone and hub. I'm using 7805s to provide power to each the BeagleBone (which requires one amp) and the hub (which should be about a half amp). The 7805s require at least 7v to function. So, I bought a 4AA battery holder to step up that voltage. Now, if I were to hook up that voltage to the motors, it would be way to much.
- Could I safely run a wire from the middle of the battery pack to the motors?
- Would that end up killing one set of batteries before the other?
- If so, I've read that the less dead set will try to charge the other set. Would that matter if I'm using rechargeable batteries?
- Is there a way to step down about 4-5 amps without too much cost or wasted energy (via heat)?