Help Please - enjoying Alaska but need advise

[menalice]

Hi All - We are in Alaska on our motorhome and would really like to know that we are doing all we can to get the most out of our PV system (3 each 215 watt panels - Midnight Classic Charge Controller w/ whizbangjr - 3 each 150ah Trojan 12v deep cycle batteries - 2000watt pure sinewave inverter).  All of the components are new and (probably where the problem lies) did the install myself.  I am getting plenty of power and we are trying to be conservative but - even when we have a "Float" condition is the evening, at dawn I  find we are reading 12.2v and this concerns me.  I have checked for phantom loads, I even put a switch in the power leg of the slide because we found that they have a constant drain.  Are there settings in the MidNite Classic 150 that should be set to "shut the system down" during the evening hours?  Anything of help would be appreciated.  It's not to say that we are not enjoying AK, but we would like to be more at ease about not depleting the batteries and causing permanent damage.  Thanks in advance!

[Westbranch]

you have a problem IMHO with the absorb portion of the charge regimen.  You can reach Float based on Voltage and not really done a full charge.

What are the settings for each phase of your charge  and what are the min and max for  Absorb?

you can turn the backlight on the MNGP off , but that is only ~ 3 Watts I believe.

ADD: did you do a commissioning charge?  Have you done an Equalizing charge? Do you have a Hydrometer?

[menalice]

Thanks for the response - I did fully charge the 3 batteries prior to install.  (BTW -all new Trojan T-1275).  I would appreciate assistance in selecting the appropriate charge times for: Daily Charge (I assume = absorb) and for Float and Equalize.  Trojan states that the "Daily Charge is 14.8v, the Float is 13.2v and that the Equalize is 15.5v.  These are the setting I used but the time for absorb and equalize and the frequency of equalize are in question.  I have done manual equalize but I am not sure that it was completed.  I have an electric de-sulfate\charger and will be on shore power for three or four days next week - if that helps.  Also, I think I remember a setting for location (lat and lon) - would that put the charge controller into a sleep mode and would that help or am I just thinking that it's searching for power - then back to resting?  I broke my hydrometer - but can purchase another tomorrow.

Ah, the settings:
EQ is set at 15.5
Absorb is set at 14.8
Float is set at 13.2

Absorb is set at 1 hours
EQ. is set at 6 hours

I agree that the backlight is nominal.

Thanks again -

[tecnodave]

Menalice,

Do you have a Multi power source refrigerator?  Some Dometic and others that can use 120 v.a.c or 12 volts d.c. or burn Propane gas are fooled by solar charge controllers . They detect engine running with a logic board in the frig and when engine run is detected the fridge switches to 12 volt power or if frig "sees" 120 volts AC it switches and uses that. On DC they use 25 amps. Some can be locked on gas. Check if your frig is running on gas only.

Enjoy Alaska, I did 25 years there before I saw the lower 48, born in the Matanauska Valley

td

[zoneblue]

Hi All - We are in Alaska on our motorhome and would really like to know that we are doing all we can to get the most out of our PV system (3 each 215 watt panels - Midnight Classic Charge Controller w/ whizbangjr - 3 each 150ah Trojan 12v deep cycle batteries - 2000watt pure sinewave inverter).

What was the design load and production figures? How much are you using in practice?

All of the components are new and (probably where the problem lies) did the install myself.  I am getting plenty of power and we are trying to be conservative but - even when we have a "Float" condition is the evening, at dawn I  find we are reading 12.2v and this concerns me.  I have checked for phantom loads, I even put a switch in the power leg of the slide because we found that they have a constant drain.

Your absorb is set to one hour? Thats probably too low. Do you have end amps turned on, and WbJr selected?
12.2V does sound low for dawn rest. 12.4V would be sort of where you want to be. But that does depend an awful lot. On the classic the absorb time setting (assuming you have a firmware 1370 or better) is the max time. SO regardless of EA, your absorb is maxing out at one hour. If you have 12.2 rest (temp depending) thats about 50% SOC. A bit low for daily cycles.

Are there settings in the MidNite Classic 150 that should be set to "shut the system down" during the evening hours?  Anything of help would be appreciated.  It's not to say that we are not enjoying AK, but we would like to be more at ease about not depleting the batteries and causing permanent damage.  Thanks in advance!

Assuming its a full classic the classic is likely drawing approx 5W, so overnite thats about 60Wh ... out of 2500kWh bank capacity, so not too bad. I believe turning off the arc fault protector does help a little, but to be honest i dont think this is your problem. Most likely a case of underestimating your overnite loads, and/or combined with not absorbing fully as wb said.

The recomended proceedure for setting absorb is as follows:

1. Choose a suuny day when you can be around to watch the system, and you have nothing too serious loads running.
2. Temporarily set abosrb to 8 hours.
3. Make a note of the time that absorb starts.
4. Note the WBjr current every half hour, or 15 mins maybe better
5. Also if you have a hydrometer check the SG on the same interval.
6. What you are looking for is either the charged SG specified for your battery (maybe 1.270-1.280), or the WBJr current to reduce to below the specified ending amps, usually somewhere in 1 or  2% of battery Ah. (eg  4.5A -9A) region.
7. When that occurs the battery is charged. Note the ending amps, and set that in the EA section making sure to tick use WbJr. Also note the time it took, add about 1hour and set the classic absorb setting to that. This is a fall back so that itll will terminate one way or antother, but as a general rule will stop earlier as your end amps are reached.

Thats the charge side. For the load situation you need to accurately assess you much you are using overnite. Theres lots of ways to do this. If you have a dc clamp meter, you can check varous parts of your system, but reading the WBJr current will also work. Note the reading a few times over the evenign, and just before going to bed. Tally that up in Amp hours, and see if matches the sort of drain you appear to be experiencing.

If you are running a fridge, that is likely the culprit, a fridge would be a tad tight on your system, but doable if all was optimally designed.

[zoneblue]

One last thing. How did you measure the rest voltage, do you have a decent multimeter? Some meters are shockingly inaccurate. The classic is usually pretty good, but its good to check anyway.

[Resthome]

Zoneblue has offered some good advise. For sure the 1 hour absorb is set too low. You are not getting those batteries fully charged. Need to know if you are using the WBJr for end amps and what the settings are.

[menalice]

Thanks again for the response - I changed the settings for the Absorb period to 8 hours until I have a sunny day and can monitor the charging. (cloudy today w/ some rain in Anchorage) 
We do not run the refrigerator on DC at night - sometimes, if we have plenty of sun we do use it on AC during the day and we use it on AC when we are running down the highway.
This was a "moving day" for us, relocating to a new area so I did not get the hydrometer but I will and will check the SG. Trojan says 1.277 +/- .007 @ 80.
It is the MidNite Classic 150 - however I have not done much with the whizbang jr settings - I know, why did you buy it if ~~~. 
Okay, so now I will attempt to set the whizband jr to control the "end  amps".  ah, 150ah per each x 3 = 450ah total.  So, is the desired "End Amps" something I should get from Trojan?
I will visit the Trojan website and look for that data.

I am thinking that increasing the Absorb time may solve most of my issues (indicating fully charged until the source of charge is removed).  I am currently on shore power and the on-board charger should have the batteries fully charged before we turn in tonight.  I will disconnect from the shore power and check the battery voltage before we turn in and again when we rise tomorrow. (hoping we have not damaged the batteries by not fully charging them for several days)

Because I suspected a problem we have used very little or no power at night and I have used the generator when allowed to help replenish the batteries.

[Westbranch]

To check the 'at rest voltage' you will need to have about 3 or more hours after the charging has finished...
Checking right after you turn off the charger (PV or SP)  will only show you where the charger has got your battery to... like 14.4V for example.

8 hours may be a bit long, watch the electrolyte level closely over the next few days, if you get excessive gassing cut it back to 4hr and re-watch, if no gassing may not be long enough so try 6 hrs. etc , etc.
You could also try an EQ on shore power if you have time

Let us know the pre and post charge hydrometer readings, they will tell a lot.

The WBjr should be set to ~ 1% of the nominal battery Ah capacity