I should have mentioned earlier that my current solar panel has a regulator fitted within the confines of the aluminium frame - it was one of the reasons for buying the panel and it is a big improvement on the previous panel which I inadvertently left unsecured on the boat cover (it fell off and smashed on the ground).  The new panel also has a diode fitted to prevent the batteries draining when the panel is in low light conditions.
With all of that said, when I have had the boat standing unused for a month or so, I hook up a standard charger to the batteries just to be sure the batteries are fully charged at least monthly.

Real cheap battery monitor.. get a $10 multi meter and replace the probes with cig lighter plug....
Or turn on your gps/ sounder  most have voltage read outs....
Either if note the voltage drop when firing u the engine and/ with engine running with everything turned on will pick up and faults in charging and/ or battery conditions... before they become an issue.

Thing I like about the Ctek is you can see the condition of the battery at any time, you don't have plug things in, turn on fish finders. When the boats sitting in the driveway with the cover on I just lift up the cover and can see which color light is flashing and know if I need to plug the charger in.

Then if the battery needs charging, I don't have to undo the battery box, I just plug the Ctek charger straight into the end of the comfort indicator.

Ctek also do one you can mount on the dash. I have a battery mounted on the front of my trailer for my electric winch, I used one of the cheap solar chargers but I found it just wasn't up to the job. As the battery got down from use the solar charger just didn't have the grunt to charge the battery back up again. Might be been alright to maintain a charge level but as far as charging a battery even a small amount they are just a waste of money.

have a 5 watt panel on my tractor battery, with a charge controller, and it struggles in the winter.
I assume the panel is mounted for best direct sunlight... the main issue with things like tractors, even electric fences as I have mentioned above.. dirty battery cases tops, espec when get damp causing leakage in excess of the amount of sunlight and what the panel is capable of.. espec at night

Battery tops must be kept clean at all times.

The battery is removed from the tractor and stored in the shed. Clean and dry,
the reality is that the 5 w panel isn't up to it even hough it's on the roof pointing north..
I am looking at a 160 w panel and more house batteries to run a fridge in the caravan, so the 40 w panel might take over tractor battery duties..

the modern day panels work with limited sunlight but trickle is exactly that,they will not keep up with demand off grid,MATTOO, when anchored just run on house,my house is 560? and is more than enough as per previous thread, and cabin lights with electric fridge which we turn off at 10.00pm ish and on 7.00am ish(waeco)and still enough left to start diesel if we forget to turn starter battery on. 

So I'm sure I owe this post an update.
Those panels didn't work.

The why, well, I put on far too many toys.
And as I set this rig up for staying away for more than three days I started to have huge energy shortfalls.
Nievely I thought my alternator would pick up the shortfall.
How wrong was I.
After a few subsequent series of energy failures. Several that I lost throttle control multiple times during anchoring, refuelling and then loss off power returning from a long days trolling and fortunately in large but forgiving and following sea and with numerous assessments between each experience I have put the effort into solving the problem.

I completely lost my GAMEFISHING season. Still I like to come home and won't put anybody on board.

So what I knew was that my smart craft and fly by wire was continually failing.
Smart craft being the tool for mercury.

I had two one year old batteries that both collapsed.
A start and deep cycle.

First port of investigation was the batteries. All good on purchase.
Then the alternator.
All good and in excellent condition.
I then spent months chasing my worst subject.
Electrics.

In this learning I discovered I had an energy shortfall.
I built an excell program to list all energy use and input.
I discovered I had a 2000 watt loss every 24 hours.
Hence day trips were just ok and longer periods were the problem.
Again too many toys right.

Energy loss of that magnitude effects the smart craft and fly by wire system with those items needing minimum operable current draws.

I'm going to miss out the finer details of all of this and try and keep it general.

So firstly I have an energy loss against what I could produce.
So as the start batteries are the most important to an isolated use of energy loss to computer, steering and throttle I've now put I n two start batteries on recommendation from mercury and others.
I've increased the house batteries to two and increased the amp hours.

I couldn't improve the alternator either by replacement or size.

I could improve the solar array.
So I now have a 150w unit with a victron 75/15 solar controller.

Now without adding another generating source of energy such as a generator I have moved forward.

So with energy use management and new energy storage systems I'm hoping for a better outcome.

So that's my abbreviated story to date.

I use a Projecta 120w folding solar blanket when doing extended camping trips, I connect it through a meter to a ctek dc/dc charger which regulates the voltage. The best i have had from a days charging is 48 amps total for a day, which is adequate to keep the 100AH deep cycle topped up, running  lights and a 80l engel fridge set to 1 degree ( cold beer is essential)

Oh, and many years ago, I was advised, spend money on efficiency, not capacity. Get efficient alliances and lights, instead of huge batteries and panels.

Titahi,
Onto it.

The supposed quality of the Victorian solar controller was a myth.

Even supposed marine solar specialists didn't see the fault in my system.

The Victorian was great with the app.
But actual use in my needs, failure.

What I learnt over some time was possibly a dc- dc convert or was a better answer.
So I purchased a redarc tool.
It linked immediately.
Haven't done a full trial yet.
But it suggests the best alternative yet.

I'm reservedly happy.
Will report on actual results.

Many of us in campervans have been running full solar systems for quite a while.  On mine and my wife's small van we run 260w of solar with 210ah (2x105ah deep cycle batteries) and that works a treat for us.  We never need to plug in.   The house batteries are connected via a VSR, but I don't think that really adds much power to our batteries in reality.