The best thing I can say about this unit is that it has not failed after several years of use, nor has the MPPT charge controller it is mated with in my system failed either. That is reliability, so the rating of this unit got an extra star. However, I can't really recommend this digital meter based on how difficult it is to use. The interface is non-intuitive, and the instructions provided read like IRS tax filing instructions. I purchased this over 10 years ago and it doesn't look like the instruction manual has been changed or updated at all (I briefly reviewed it again, the pagination and information on the bottom of each page appear the same, though I didn't do a line by line comparison with my original manual and the online version at the Alt-e store). I also reached out to the manufacturer regarding any firmware updates and got no response at all. Even the function/display buttons on the unit don't work well; they are loose and stick very easily and when using the meter you end up going into data screens you don't want and then it is hard to get back to the screen you want. Even the backlighting on the tiny display is weak, and the LCD numbers are hard to read in ambient light. I definitely would not purchase this meter again. Sorry Morningstar, I had higher hopes for your products based on your reputation.

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