I got a small panel with the idea of maintaining the caravan battery, set it in the window of the caravan, but it was useless, would have been better off simply disconnecting the battery. But a friend did the same with a tractor, and it did seem to work.
If I walk around my garden, there are lighting spikes my wife has bought, some seem to run for years, others have died after a month, and some spring back into life every summer.
The internet is full of kits
and we have no idea which do and don't work after a year of use.
this looks good, but how long would the power pack last without the solar panel, we don't know,
The problem is lithium batteries are rarely 12 volts, so all the time we are using them we are also powering an inverter, and lead acid batteries take power just to maintain the battery, so more worried about losses to what the camera uses.
So an 80 Ah fitted to wife's car, AGM type, over Colvid was switching the charger on once a day, nearly always same time, so assume the car was sending info back to Jaguar? But the power use was very low. Also, 80 Ah also reasonably new, on a Kia, this time a flooded battery, was needing 4 times what the Jag was using to keep battery maintained, and the little Honda Jazz with something like a 40 Ah was also using a lot compared with the Jag.
But the 35 Ah AGM on the mobility scooter used even less to the Jag. And the 20 Ah AGM in the jump start battery pack even less again. So we have to ask is it worth it? I can so easy recharge the jump start pack, and so easy to carry, likely better simply charge it up one a month, I looked for a Tapo 9 volt camera found this
but nothing to say how much power it uses. But there will be losses with the devices to get 9 and 5 volts from a 12 volt battery, well not even 12 volts really on charge can go to 14.8 volts depending on charge controller, and most droppers have an auto switch off at around 11.8 volts.
I was looking at using 2 x 80 Ah batteries which were on a car as emergency lighting, and I still need to look at cheap methods, I have a lead,
so two cig lighter sockets on croc clips so easy to connect to a battery. So two methods to use it, I have lights designed to be used when working on the car, small tungsten bulb, and a magnet to hold it on the bonnet, and also some USB adaptors for a car, and USB desk lights. As yet not measured how much each uses, ones first impression is the LED USB will be better, but there will be losses getting 12 volt to 5 volt so until I measure I will not know.
I, in real terms, could not care less if they run for 6 hours or 6 days, I have enough charged batteries around. But your step one is to measure how much they use. Easy for me, I have an array of meters to select, likely will use this one,
but that is up to you, until you measure, it is pure guess work.
