Quote:
Originally Posted by mitiempo
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Thanks for posing the link. It was discussed on the forum some time back. I read everything MaineSail publishes and would suggest anyone interested in maintaining their
boat does the same. There is some great, practical,
advice.
Like many of MaineSail's articles, it takes a scientific approach to answering
boating questions
. The results showed an MPPT
regulator beat a none MPPT (sometimes called PWM)
regulator by 20.8%. However, it it should be noted that this was charging
lithium, not lead acid
batteries. The lower charging voltage of
lithium gives MPPT a greater performance boost (as MaineSail correctly notes). I seem to also remember the temperatures were quite low, but my memory may be wrong on this point.
There has been other published data. There was a comparison of MPPT (Victron 75/15) and non MPPT regulator (Sunsaver PWM) published in the Yachting magazine PBO in 2015. The results showed a 10.9% gain for MPPT.
My own tests were less formal, but after a couple of years with a very good quality PWM regulator (Plasmatronics) I changed to a MPPT controller (for another 5 years worth of getting nearly all our
power via
solar and MPPT). I noticed about a 7% improvement.
These differing results are to be expected. The exact improvement will depend on many factors. Perhaps the most important is temperature. In the warmer climate of the
Med it is not surprising I noticed less change.
I still think my ball park figure of 10% is not a bad starting point for those trying to decide if the costs and complexity of an MPPT regulator are justified. However, I should have qualified this number by pointing out this assumes a lead acid bank. I would once again stress that the actual average gain may be higher or lower than this and also stress that this is for a quality MPPT controller.
Cheap MPPT controllers can be poor.
As long as you don't believe the commonly quoted advertising line of a 30% gain or the opposing view, as suggested in this thread, that there is zero gain for "12v panels" then you are more informed than most.