Optimizing helmet power sources

[kiyotei[TK]]

I run a fan and a sound system in my helmet (radio shack mini amp). The fan batteries (I use two 9 volts) die in about an two hours. It gets really frustrating and I have to carry a lot of batteries with me. I also use a 9 volt for the amp. Enough is enough. My fans died while trooping PAX in Seattle this past weekend and I had serious heating issues. So I looked online and ended up going to Radio Shack and buying a large Remote Control Car battery. It puts out 9.6 volts rated at 1600 mAh (milli-amp hours). A typical 9 volt battery is about 120 mAh. The fan I use is the 12 volt 120 mAh fan most people buy at Radio Shack. So in theory running the fan and amp off of this new rechargable battery pack means I'll get about 12 hours of fan use (1600/120 == 13 hours). I know you can buy ultra life 9 volts with 1200 mAh but they cost $13 apiece and you will always have to have a spare set with ya cause you never know when they will die. The RC car battery pack and charger were not very expensive. After about 3 troops it will be paid for in battery savings. I'll post photos once I finish mounting it in my helmet. I had to add a diode in line between the battery pack and the amp to drop the voltage to about 9 volts because the amp is rated at 9 volts. I couldn't find any documentation on the amp so I didn't know what max allowed voltage for it is. Now that I have lots of power I may add my second fan back into the helmet. I cut slots in the back of my helmet some time ago for better venting and so I mount the fan over the vent holes to draw air in. I find that works better because my head really blocks the air flow its sucking out (exhaust vs fresh air.). Plus having the fan pointed in helps circulate air in the helmet.

[Daetrin[Admin]]

Fascinating! You'll have to post pix now, you realize?

[blinki]

Daetrin you beat me to it

[kiyotei[TK]]

Yes I know, I said I would post pics as soon as a I finish installing it all. The wiring done now I just have to rig a harness to hold the battery pack.