Ghetto Blaster Reloaded

Status: Getting there


July 27, 2009

2 4000mAh 4-cell Li-poly batteries just showed up from Hong Kong. In trying to figure out a reasonable charge method, I came across this. Were there not at least a reasonable chance of explosion, it just wouldn't be ghetto enough.

And holy crap chargers/balancers are expensive! But really, what are the chances I could screw something up with ~120Wh of potentially explosive cells that I know nothing about?

The old ghetto blaster was a terrific success in providing obnoxious music wherever I wanted to go. Still, the battery doesn't last that long and it looks kinda like a bomb so I'm making a better one. Okay, so that last part isn't going to change. In fact, it will look even more like a bomb and will provide an extra bonus explosion hazard. This project attempts to dive into the world of lithium polymer batteries in search of a greater supply of terrible music that can be shoved through the eardrums of innocent and unsuspecting bystanders.

So why lithium polymer?

I intend to use the same TDA7377 car amplifier but this time with a preamp. At 12V, the amp does not have enough gain to clip most sources. I at least want to have the option of driving my power sources as far as they can go. Battery charging will be handled by a Dell charger for a reasonably high power 19V supply. Cell balancing, charge controlling, and a hopefully a spectrum analyzer will likely be handled by a dsPIC30F4011.

Back to more useless crap

Valid XHTML 1.0 Strict