MNGP Volts vs Battery Charge

[ChrisOlson]

1) I have an older trimetric 2020... how does yours work?  On mine, I set 'end amps' parameters that, when met, cause the trimetric to reset to 100%.   If my charger and my trimetric both use the same parameters, then both should be fooled when the parameters are met at less than 100% SOC.  Why does your trimetric get it right when your charger gets it wrong?

Ralph Hiesey said the menus are different in the TM2025 so I don't know if it's the same in the 2020, but menu item P12 in mine is set to OFF.  That is for the auto reset.  The only way mine can get to 100% SOC is to do an actual "countdown" and replace every single amp-hour that was removed during discharge.

The TM2025 also has a different algorithm for CEF.  It uses "weighted" values that assume higher than your CEF setting during bulk charging and less than your CEF setting when the battery is above gassing voltage.  So it's a little more accurate than the TM1, TM2 and TM2020 on PSOC cycling.  Ralph has a newer model yet now - the TM2030.  It uses the same algorithms as the 2025 but it is designed to communicate with and control his new SC-2030 solar charger.

2) How did you maintain your batteries while you were gone?  Were they cycled, or were they on some 'float' type maintenance?

Well, the solar panels were supposed to maintain the batteries but they ended up getting buried under 3 feet of snow.  I had the south facing array tilted up to almost vertical and even it got plastered and the snow built up so the bottom half of the panels were covered.  The system stayed running and powered the 'fridge and freezer fine.  But the batteries got down to 28% SOC, and they were below 40% for at least 10 days.  I looked in the TriMetric's history menu and H2.1 (length of current cycle) was at 459 hours.  H2.2 (length of previous cycle) was 61.8 hours.  H2.3 (two cycles ago length) was 48 point something hours).  So everything worked fine for the first three weeks or so and then a major blizzard buried those panels and the system ran on straight battery power for three weeks with no charging at all.

[vtmaps]

Well, the solar panels were supposed to maintain the batteries but
<snip>
The system stayed running and powered the 'fridge and freezer fine. 

So you shut down the wind turbines.  How did you heat the house? (I thought you only had wood heat).

--vtMaps (getting more and more off topic)

[ChrisOlson]

So you shut down the wind turbines.  How did you heat the house? (I thought you only had wood heat).

I've never felt that leaving wind turbines running unmonitored is a good idea.  Originally we were going to have some house sitters.  When that didn't work out we shut the water off, drained the sink traps, water heaters and lines and left the house cold.  The only things we had running was the 'fridge and freezer and a box fan running on low that blew air from the basement to the upstairs.

Our weather station keeps daily history of the inside temp in the house as well as weather conditions.  With the box fan going (only about 50 watts) the history stored in the weather station says it got below freezing in the house for only two days - and most of the time at 32-35 degrees.  The inverter's power consumption at idle (no output but inverting) is about 40 watts.  So the inverter actually used about as much energy doing basically nothing as the box fan did.