You do better to build a custom solution but it will cost some $$$
+1,
Have to agree that you either pony up for a purpose built commercial product or go all in using custom parts. Which can be mimic’d by following what other companies like Hikvision are using.
The biggest difference is how they send data and that isn’t via wifi / Ethernet.
That’s using cellular and that still has latency and drop outs depending upon how far the tower is! I’ll offer my personal experience as to some things to consider if you decide to go the custom route.
Camera: Find the lowest current draw hardware you can find which balances low light video performance. If you find a camera that consumes less than 0.15 amps you have something to build upon.
12 VDC / POE: As noted up above depending upon which power option is to be used one may offer that low current ability but more often than not it’s going to be POE with higher voltage.
Battery: Normally the battery configuration dictates what method will be used in the past. Given the market offers all kinds of DC boost / buck converters you’re not limited by battery config. Having said this the vast majority of off grid systems are Series / Paralleled to obtain 24 VDC while offering higher ampacity.
It’s pretty rare to see a 12 VDC system in the field that isn’t paralleled to achieve a longer runtime vs a 24 VDC system that is simply bucked down to maintain a constant 12.8 VDC.
Given the increase in availability of LiFePO batteries and cheap cost it makes very little sense in ever using standard SLA, AGM, Gell, etc. Having said this you must insure whatever battery you select is weather rated to the environment it’s intended to be used.
LiFePO batteries don’t like to be hot or cold. But some offer a wider working margin vs others.
Charge Controller / BCM: All lithium batteries use a BCM to manage its voltage insure the correct one is used and offers the safety cut off to protect the cells. The charge controller needs to be a MPPT vs PWM as it is more efficient and extracts more power from a solar panel. A good charge controller will monitor the temperature, temperature, current, and have high / low cut offs to protect the batteries. Every battery chemistry has a terminal voltage that you must not drop to as it will damage and shorten its service life!
Solar: The only solar panel to use is Mono vs Poly as they offer better low light (cloudy) energy production. Depending upon your region you’ll need to factor in seasonal solar generation or the lack there of. Meaning if you live in the north like me you’ll need to either Series / Parallel to achieve higher voltage or higher current to charge faster a depleted battery cell or to position the solar further away to achieve better solar generation etc.
PTP: Since this is solar you’ll need to install PTP bridge at the camera and the site to relay the video. If you don’t have a clear line of sight or there are lots of other RFI / EMI sources. You’re going to be losing hair everyday trying to compensate for connectivity or the lack of.
Good Luck!