Philips SBC HC8545 headphones

I've been using a pair of wireless headphones for some years now and the batteries are pretty much near the end of their life span, so what's the problem?


The problem are the batteries. Philips wants you to use their recharcheable batteries. What happens if you use other batteries? You get a perfomance drop; shorter battery life and an extremely reduced charge rate when placed in the base.
What makes their batteries special? Nothing much really, the only difference is that the batteries have an area near the negative terminal that is not insulated like the rest of the battery.
This terminal simply bypasses the reversed diode (zener? I didn't check) reducing the voltage drop on one of the batteries and I'm pretty sure that on the PCB there is another diode/zener for the other battery (why not just hot glue it like the other one? I didn't bother checking).
Here you can see the "special" terminal that conects to the battery case (anode) to bypass the diode.


This is how the battery interfaces with the contact terminal. Oh, look! A warning label!


And here you can see the complicated solucion to this problem, a pair of wires to permanently bypass the extra circuitry. Of course, this could also be a protection measument if you decide to use non-rechargeable batteries, but as I never place the headphones in the base when I'm using normal batteries because... well they're not rechargeable!
Hope someone finds this usefull! Happy hacking!

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