When I was looking to add a solar panel I did my research....There are various controllers, all take the voltage from the panels and put it into the battery and also protect the battery bank from overcharging. Some do it very simply some with more finesse.
I opted for the Sunseeker MPPT (Maximum Power Point Tracking) It was not the cheapest but it puts more into the battery bank than the lesser PWM (Pulse Width Modulation) type - the Steca being very popular and the one the now defunct chandlers at Burton on Trent tried to sell me.
My understanding (basic) is that the MTTP works with the batteries to monitor them and try to get as much charge into them as possible compared to the PWM type that stop when they read the battery voltage as being a certain amount. I interpret it as the MTTP is like a clever battery charger. Anyhow it works and today when I visited to collect my phone I left behind the batteries were 100% on the Samrtgauge - that is 15% from last week. I also read on my research some owners with Smartgauges and PWM controllers were not getting the Smartgauge up to 100%
As noted before it is doing what we planned and this is over winter so I expect better as the sun gets higher and shines for longer. I like the frame that Ian on NB Freespirit has constructed - this seems like the real deal, might enquire on commissions for other boaters solar panels....
Anyhow the Sunseeker has a 30 day log of lots of info. I have taken just one piece of info - IMHO the most important - the amount of charge going in.... charted over the month of October
13 hours ago