Is it possible to charge the 12vdc (normal car battery) using a trickle charging in the cigarette lighter plug? I am thinking of using that and a solar panel to keep the 12vdc battery healthy because I have an always on dash cam. The purpose behind the always on dash cam is to try to catch potential thieves. My concern is that I don't know the wiring between the 12vdc battery and the cigarette lighter adapter. If there something that isolates the two circuits it won't work or it could even damage some sensitive electronics. If anyone could point me in the right direction for electrical wiring diagrams that would also help too.
The 12v lighter plug is not live unless the car is “on”. Doubt you’d want to leave the car on all the time.
Why not keep an external security camera pointed at your car? This would give better coverage of potential thieves. Otherwise, if you're thinking of solar power, could you just power your inside dash cam with the solar when it is sitting parked?
IF you end up doing what you propose, don't "cheap out". You need a solar panel and controller that produced at least as much wattage as the camera uses. And if the camera runs 24/7 (at night too) then the solar needs to have more power for when it's dark. As was mentioned, the 12 V socket is not "hot" when the car is off. Best to connect a quick connect "pigtail" to your battery and connect it that way. That could also be used for "real" battery charger should the need arise.
I suggest making the installation independent of the car, by using its own battery. If you can find a camera that suits which will run off of USB (5VDC), you might try using a solar USB charger such as this one from the big "A". Solar Charger 25000mAh, Hiluckey Outdoor Portable Power Bank with 4 Solar Panels, Fast Charge External Battery It would provide the battery, solar cells, and a charging circuit all in one package. If the pack ran down due to clouds etc. you could charge it from your USB port while driving the car. At 500 mA draw this unit should power without sun or recharging for about 2 days. If the camera unit you want to power must have 12 VDC you could add a DC to DC step up converter from the big "E" for 5 bucks. USB DC 5V to DC 12V Step up Module Converter 2.1x5.5mm Male Connector Check the current ratings of all components for suitability of course.
