Can I hook up a 5V source to the hard wire kit with a DC 12v to 5v converter and still power on the dashcam? The DC converter input should be a 12V and out put is 5V but can I use the 5V as the input source?
Basically yes, that should work fine, but charging a power bank can take quite a lot of current, it is quite likely that a normal 1.5A or 2A hardwire kit will overheat and start turning itself off, should be no problem with a 5A one, or probably easier and neater just install an extra converter to charge the powerbank.I have a A118C hardwired to the car 12V using the hard wire 12v to 5v kit but, I'm planning to add a 5v power bank to the same wire so that I can switch to the power bank to power the dashcam when the car is parked.
No, not trying to charge the power bank with the car 12v
The power bank will charge fine, but if the charger decides to limit the current because either it is not capable or because it gets too hot then the voltage will have to drop and then the power bank will keep charging fine at a lower rate but your camera may not be happy. Safer to use separate chargers for power bank and camera and then there is no problem.Most power banks will charge just fine with one or two amps and that is often the recommended current from manufacturers. It just can take quite a few hours to charge depending on the size of the bank. The charger will warm but if it doesn't get too hot you should be OK.
The power bank will charge fine, but if the charger decides to limit the current because either it is not capable or because it gets too hot then the voltage will have to drop and then the power bank will keep charging fine at a lower rate but your camera may not be happy. Safer to use separate chargers for power bank and camera and then there is no problem.
That will not work, nearly all 12-5v convertors need at least 7v in before you get 5v out.I attached a circuit's diagram of what I mean. When the car is not running, the relay rest on 87A and the 5v power bank's circuit has a clear path to the dashcam. When I start the car, the relay switches to 87 and thus cut off the power bank and power the dashcam through the car 12v system.
My question is will there be any problem since the 5v from the power bank must travel through the 12v step down converter before reaching the dash cam?
As far as charging the power bank, I can bring the power bank inside the house and charge from the wall outlet or charge it with the car 12v outlet when the power is off
That should work. You might want to add a flyback diode, otherwise when the relay is turned off it can generate a voltage spike that could damage other circuits.The relay will need 12v for the coil 86 to be energize.
What is the reason you think that it is desirable to switch the 0v as well as the +5v?Like i said DPDT switch (or relay) to isolate the two circuits completely.
You need a 5v power bank that will automatically turn on/off when a device is detected.