One of the insane things about some Baofeng hand held radios is that the charger cradle requires 10V DC, and malfunctions on car battery voltage.
The cigarette light adapter that came with a Baofeng GT-3TP was simply a pass through device and the charger did not work properly using the adapter plugged into a car.
The charger cradle electronics should include electronics to charge properly from a car, preferably from 10-16V. The implementation is a half-baked idea.
To solve the problem I have made an adapter cable using a small buck DC-DC converter off eBay (~$2), the converter is adjusted to 10V out.
I have used an Anderson Power Pole connector to suit my power distribution, you could use a cigarette lighter plug or some other plug to suit your needs. The output connector is a 2.5mm DC plug. Continue reading Baofeng charger DC-DC converter