I suppose its about time I reported back on our solar panel, LED lights and all that as its a few months since we had them. Our objective was to be able to survive a weekend without running the engine to charge the batteries. Previously we couldn't do this, mainly due to the fridge taking a lot of power, and the inverter too, if we used it to watch our 240v TV.
The first thing to say is that we certainly can now survive three or more days ( at this time of year) without needing a charge from the alternator. This is down to four improvements
1. The solar panel - a kyocera 95watt panel with an MPPT controller.
2. LED lights, which we use in preference to the fluorescent strip lights and use about 90% less power
3. A very efficient 12v TV (Meos) which takes only 30watts and gives a great picture.
4. Intelligent fridge management - i.e. having it on lowest setting when the engine is not running - this is still plenty cold enough, and turning it up to full whack when the engine is running as after a few minutes the alternator has amps to spare and we build up a reservoir of cold in the fridge.
When we were at the boat a week ago it went like this
(measurements taken from our Smartgauge)
1. On arrival batteries at 100%
2. Bedtime - batteries down to 82% - fridge takes a lot when first fired up and we watched a couple of hours of TV
3. Next morning 72% - no solar input overnight of course
4. Dusk that evening 82% -i.e the solar panel ran the fridge and put 10% charge back into the batteries
Over the next day or two we were cycling between 68% and 85% roughly speaking. This is powering the fridge plus a couple of hours TV plus lights and bits and bobs (water pump, phone chargers etc etc.)
So we seem to have cracked it, at least for the summer months. I should say though that it was a very sunny weekend. We left the boat with the batteries at 85% or so, and I'm sure they'll be back to a hundred by now.