I did mine a few years ago... I actually changed the controller to a double charge controller so both batteries where charged. I found I only need to charge them manually a few times a year.
Do you have a link to this double charge controller by any chance , i just want a read up on it , i must have missed these on my hunt for bits !
Rich
Here's one
http://www.selectsolar.co.uk/prod/836/morningstar-sunsaver-duo-monitor
But its still a pwm controller. It can just split the amps to charge 2 batteries. If you had a Durite VSR linking your starter and leisure battery together then an excess watts from your panels in summer would go the charging your starter battery.
Funnily enough, I read a comment on the canal boat forums that there is a question if an MPPT controller is better than a PWM controller for solar panels smaller than 200 watts.
Bit I haven'ty found any other 'expert' confirming that.
I think that MPPT comes into its own when you have over voltage , I have been watching the watt meters very closely lately , due to my wrongly named "Epic fail " , I just got a bit c*cksure of myself thinking i had it cracked !
This week i have worked every day and am nowhere near the low voltage that caught me out last week , I have been pulling in more or less whats been going out give or take 1 amp , this is replaced the next day before i get in the van for work .
The next move for me is to replace the single 80 watt panel with 2 x 60 watt panels , why , well the 80 watt has been giving me about 15 volts in cloudy conditions , this over feed of 3 volt has been converted to an extra half amp with the MPPT doing its thing , I will run the 60 watt panels in series giving me at least 30 volt , thus being over voltage of at least 15 volt , on paper this should give me a 2.5 amp boost per hour , which should come very close to my amp usage per hour , its all very much pie in the sky to be honest , but i dont see anybody else doing it for me !
It wont be a waste either way as i have the extra MPPT sat doing nothing at the mo , i will couple that up with the surplus 80 watt panel and whack it on the shed , the solar geeks man cave !