Drake,

--- You wrote:
I called her back just now, and the voltage readings on the Mate, MX 
and Trimetric all match.  Humm.

The batteries are 4, 4 1/2 year old, U.S. Battery L-16s wired in 24 
volt configuration.  It seems that I remember postings of Wrenches 
having problems with these batteries.  There is about 1 KW STC of PV 
on the roof.

--- end of quote ---

Is there any chance she initially read the array voltage on the MX60 
instead of the battery voltage? Both numbers are displayed 
simultaneously, of course.

This is a relatively small battery bank. Could it be getting tired, 
somewhat prematurely? Charge rate is right up there, ~C/8.
Tired battery + high charge rate = lots of H20?

Dick Ratico
Solarwind Electric
Bradford,VT

