[Android Head-Units] kaween:
Yeah, wrong link. I only saw it days after posting and kind of forgot about it after that. But the correct 120 is on that page too, and it clearly states "ideally suited for vehicles" so I didn't think twice about it.

As for your "Last Concern". No, that's physically impossible. The Pico board has 3 sets of connectors.

1) Vin (Car charging Circuit)

2) Battery connector (where your "buffer battery" will be hooked up)

3) Output (Where you should connect at least one, But I advise to connect BOTH voltage lines of the S150). But the S150 has NO direct connection to the car's electrical system anymore : the Pico sits between it. Also, I advise ONLY the radio to be connected to the Pico to avoid overloading it. The Pico can deliver up to 6A without extra cooling : that's no problem for a S150, even not with a DVB-T and Wifi hooked on it (the S150 will draw typically 2.6A under such circumstances) but if you'd be using an extra amplifier together with the S150, the PICO could get into trouble if the amp is big enough).

The moment the Pico UPS Vin goes Below 13.2 V (it's actually more like 13.4, but my car pushes 13.7V when running), it stops (trickle) charging the battery. From that moment on, the PicoUPS will feed the load with the input that has the highest voltage (it compares Vin and Battery, and switches withtin 100ns).

So no matter what reason the VIN drops below the voltage of the Backup Battery, the load will receive its feed from the backup battery.

As a charged backup battery will show 12,6 at lowest, the pico ups will switch to the backup battery long before your main battery drops below 12V. It makes no difference WHY the voltage of the main battery (Vin) drops below the Buffer Battery Voltage. The Pico doesn't care : it simply compares both voltages and switches to the highest.

So unless your backup battery is dead, the S150 will NEVER cope with a voltage below 12,6V.

And the Pico will not let the backup battery go "inline" with anything that is not connected to its output. That's why you should put the Pico "BETWEEN" the car's power line and the radio, and certain not "over" it. It's not a cap. Only that way can it work correctly and switch voltage source between main and backup for the hooked load (your radio).

Its really a very nifty little PCB, and I can't build that part at that price myself. :good: I've had zero issues with it since I'm using it.

As said, I've hooked BOTH powerlines of the S150 to the Buffer. So now car radio does NOT switch off automatically when shutting of the engine, but I can run the radio without keys in the ignition and when I would forget about it, it will only drain the buffer battery, not the main battery as the Pico refuses to charge the buffer battery if the Vin is below 13.2~13.4V (which you will only measure when your main battery is charging - so when the engine is running)

As for your memory loss issue, as I said earlier, I have no rational explenation. The S150 -simply should not react like that if it is technically 100% in working order and the wiring is 100% correct- . As said, I tested my own S150 as low as 9.5V, it never lost memory and never failed to work. Only when dropping below that critical voltage, the S150 turned of and lost memory.