How do I program V-Hi and V-Lo for specific use

[stuman]

Introduction: I have a Midnite Classic 150 in my RV with 720 watts of panels and a bank of 8 Crown 6 volt 232 amp hour batteries setup for 12 volts.  What I wish to accomplish looks like it can be done with the OpportunityHi setup, but I don't know what it takes to set the V-Hi and V-Lo values.

Purpose: What I want to accomplish is to use either the 12 volt out from Aux-1 directly to control an external relay or use the contacts for the internal relay to remote "On" a big inverter with a small A/C unit on it.  I wish to activate the inverter when battery voltage is above V-Hi with a 120 second delay (in case voltage rises quickly from V-Lo) and to turn off at V-Lo to allow me to set my 515 watt A/C to be on when power is available and off before draining batteries beyond a predetermined set point. 

Voltages: I'm figuring 11.9 for the V-Lo number, as the A/C drags voltage down .3 volts while running.  This will allow the batteries to rest at 12.2 volts.  I figure setting V-Hi somwhere like 13 or 13.2 to have the AC come on with enough battery reserve to run for a bit.  I will be unable to tend it during the day, which is why I want to automate it.

Question: Can V-Hi and V-Lo be set with the control panel or do I need to interface to the controller with a computer/software to do this?  If so, which software?  It is a newer unit, purchased in summer of 2014.

[kitestrings]

I believe you have to choose either Vhi or Vlo, I don't think you can do both with the same aux output.

It sounds like you are looking at "opportunity diversion".  You may wan to consider using the Waste Not Hi (Use it or Lose it) function for diversion.  In this mode the voltage setting is relative to your charging stages, so you divert when excess power is available but maintain the three level charging.  We been doing this with water heating for a few years.  Works really well.AC

Other folks may have experience with using an AC unit - I've not attempted this - but, you may find that a resistive load is easier to divert to.  Particularly with aux2, you then can burn as much or as little energy as need/available, where as the AC will have to be on or -off, and will have some higher level of starting surge each time it cycles on.

Good luck, ~ks

[stuman]

According to the documentation, the Opportunity Hi mode with turn on when the V-Hi is reached and off when V-Lo is reached.  This is exactly what I want to do.  Turn on when the batteries reach V-Hi with a 2 minute delay just because and turn off when they reach V-Lo.  This is without regard for the charge stage, as I will set the V-Hi and V-Lo to allow for that, and I will be providing supplemental charge to the batteries in evenings when the vehicle is in motion.

Anyway, what I'm asking is how to get access to set those values.  I enter the serial number in the app and nothing is ungreyed.

[boB]

Not sure why the Local App is not un-graying out those settings ?  If it is the correct serial number, it should
just work.  Now you can set those on the MNGP as well.

You can temporarily (or permanently) bypass the serial number/password for that Classic by installing
the jumper labelled "LOK" behind the main terminal block on the Classic.  There are 4 jumpers there.
I think this one is the second from the left jumper.

boB

[stuman]

I see what I'm doing wrong.  I'll do it right tonight.

[kitestrings]

stumn,

I had that grayed out issue on one unit.  Don't recall the remedy...other than fiddling around a bit.

I'm not sure what you're thinking for a Vhi set-point, but 11.9, even with the .3 recoil to 12.2V, on the Vlo seems like a pretty deep cut to me.  At nominal voltage your down to 50% DOD.  Unless the AC is all you're needing it for I would think you might want to be higher.

With waste-not, you can get as much or as little diversion relative to your charging points (by adjusting the off-set) with voltage shift and width, and still maintain the 3-stage charging capabilities.

~ks

[stuman]

Got it figured out.  I'm comfortable with the programming now.  All I need is for the relay to hold up to 100% duty cycle.  If it doesn't, I'll have to upgrade it.

Current setup.  Aux1 Diversion.  Low voltage 12.0.  High voltage 13.x.  My load torques the voltage down 0.3 while running, so it should bounce back up to 12.3 when it cuts off.  I have 8 232 AH six volt batteries wired series / parallel for 12 volts, so with that big of a bank, I don't expect rapid voltage swings.  I will give it a good test run tomorrow before turning it loose by itself.  I will be leaving it alone from before the sun comes up, so the AC will be running with no charge input for a couple of hours in the morning.  Once battery drops, it will cut off until I get back over 13.  That should work just fine for a while.

Thanks to everyone here.

[new2PV]

You can control any device via wifi and cell phone and a 8 channel relay system for under $100, so you can really control anything remotely.

http://www.ebay.com/itm/8-Channel-WIFI-Network-IO-RELAY-BOARD-Controller-For-ANDROID-IPHONE-WINDOWS-MAC-/281647022788?pt=LH_DefaultDomain_2&hash=item41937882c4

http://www.ebay.com/itm/8-Channel-DC-12V-8CH-Relay-Module-with-Optocoupler-H-L-Level-Triger-for-Arduino-/251412513589?pt=LH_DefaultDomain_0&hash=item3a895a8335

But you would need a internet connected router connected in your setup.

[stuman]

Since my setup is in an RV, maintaining internet connectivity is not an option.  I have successfully automated the A/C so that my RV doesn't cook when I'm at the office, and won't kill the batteries if it clouds up.  Best day so far is 3.7kwh from 720 watts of panels. 

I may rewire the panels in parallel to see if I can get the controller to run a bit cooler though.  It has overheated more than once, and I now have the cover off of it so that the passing air flow from the A/C helps cool it.  The external fan seems to have quit...but disconnecting and reconnecting both panels and batteries runs it briefly during power on self test, so the fan is ok.  Is there something in the programming I need to check, or is the board temperature sensor malfunctioning?

[boB]

Stu (man) what is the input voltage running at now, approximately when it is in MPPT mode ?

750 watts should be running plenty cool enough since that would put the battery current at around 62 amps
or less.  OK....   Maybe what I should ask is what are you considering as over-heating or hot ?
FET TEMP would be the temperature to look at.

Does the Classic actually say Hi-Temp or something ?  It would have to get pretty hot, like, maybe in the 80+
degree C range...  Maybe 85+ ?  can't remember off hand but it's way up there.

I assume you got the Aux output working OK ?

boB

[stuman]

This deserves a reply.

Actually my unit was defective.  Midnite replaced it under warranty.

I have since quit using it in the RV as the RV is now parked permanently...until I repurpose the platform.  The controller will be used to parallel multiple panels on my home system, which also has a Midnite Classic 150.