MPT controllers are proven devices for boat solar power and as Dawg says can improve the actual deliverly of power to the batteries during full panel output (i.e. full sunlight) on the order of about 10-20% as they will allow use of power that is normally just wasted as heat by normal regulation.
I will disagree with Dawg about being useful primarily with AGM's as they can help any decently large battery bank...wet or dry depending on how many amps your panels are capable of putting out at full power.
Example: A panel rated at 200watts and 17.5V puts out 11.43 amps unregulated. Regulating this down WITHOUT LOSS...to a normal 14.5 volts bulk charging voltage will produce 13.79 amps.
That is the MAXIMUM current you can see with 200 watts of panels.
Since wet cells can take 15% of their rated amp hours in bulk charging amps...all that is required is 92 amp hours of battery rating...slightly less than a group31 size.
So...an MPPT controller can provide a benefit to ALL sailboat owners with solar panels that have unregulated outputs in excess of standard charging voltage of 14.5V.
Tomaz...I am not making claims for 99% conversion efficiency! Just way better than throwing usable power away as heat!!
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