OK, all you EE types out there...
Since I commute in freeway traffic every day, splitting lanes much of the time, I really need a horn that's louder than stock. Something to make it through 70 mph wind noise, tempered glass, and over a Lexus's sound system with enough volume to wrench the car driver's attention away from her text messaging.
I've always used the Stebel Nautiuls Compact air horn. This unit draws a maximum current of 18 amps. I replaced the horn fuse on the OEM 12V fuse block with a 15 amp fuse and the horn works, but it cuts off the bike. Doesn't blow the fuse. Obviously the bike's protective circuitry is doing its job, but having my bike quit on the freeway is no bueno.
So I need to know if the following idea would work:
I buy the smallest lithium motorcycle battery (small and light) and wire the horn to the battery using a relay, so the current doesn't go through the handlebar switch. Once I've done that, I have two choices:
a) I can simply hook up the battery to a tender each night when I plug in my Empulse for its daily charge.
b) I somehow hook the battery up to the Empulse's 12V supply, so the bike can continuously charge the battery while the bike is running.
The huge gap in my knowledge lies with option b): How can I do this without damaging either the battery or the Empulse's electronics? Would I need to sense the battery voltage and put some kind of gizmo in the circuit that would charge only when the voltage drops below a certain point and stop charging when it reaches a preset maximum? Would I need a diode to keep the battery from feeding current into the 12V Empulse electronics? Will the battery catch fire and burn up my Empulse?
Am I totally crazy? (Don't answer that: my wife already has long ago taken that option!)