12v car barrery to 6v to run led lighting and 6v radio incorperating a solar pannel

If you're using 12V batteries, you need a 12V charger designed to run from solar panels.

You need equipment rated for 12V. For lighting, LED lights incorporating switchmode current regulation is your best bet.

For your 6V radio (the current requirements are likely to be small) you should have a dedicated 6V regulator to power the radio connected to the 12V supply.

Your 12V supply can vary from about 14.5V down to 10.5V, so it is important to have loads that are capable of operating efficiently from that range of voltages.

 

Oh, I didn't read that it was a trickle charger.

Is that the entire source of your power? It's not going to provide much power.

What is your lighting load? I would expect that if you're in the UK you'll get the equivalent of maybe 4 hours of sunlight per day in winter (maybe significant;y less)

OK, the UK met office says 2 hours in January and December apparently.

So a 1.5W panel can deliver 3Wh per day during winter (and that's only on days without cloud or fog). That 3Wh will run a 0.5W LED for about 6 hours. It's also the load that a small radio would generate. So you could have 3 hours of something like candlelight with radio per day.

To allow for days that are cloudy/rainy/foggy, etc, you would halve that (or even cut it by 2/3).

Is an hour of feeble light good enough for you? Is 2 hours OK if you don't use the radio?

in contrast, a 40W panel would provide 80Wh/day in winter, which would allow you to run a load of just over 3W for 8 hours. A 3W LED light is actually pretty bright, and the system starts to look like it has some value.

Note that the calculations above do not take into account several inefficiencies such as losses during charging and resistive losses in cables which will make the figures look even more depressing.

Going up to a 150W, or 175W panel will give you the ability to run a sizeable load (like pretty good lighting) all night in winter. As you get to these size panels, a dedicated MPPT charger is essential and you're also going to have to size your batteries appropriately.