Outback off grid system generator not turning off (settings)

Joetool

Hi everyone, this is a great forum! I spent a lot of time reading and studying and have some questions about an off grid cabin set up that not working correctly.
 The system is composed of an Outback VFX 3524 inverter, A MX 60 PV mppt charge controller, the battery bank listed below, A mate3S controller, outback hub, two temperature sensors one plugged into the MX 60 and one into the inverter monitoring battery temperature, Generac propane 5000 watt generator, Solar array unsure of wattage(approximately 10 to 15 year old panels not exactly safe to get on the roof and check them)

The battery bank was a 1200 amp hour battery bank with mixed Trojan (4) wet cells and AGM! The plates on three of the Trojans were exposed. We just got 12 new 400 amp hour AGM 6v that will be wired in three banks (I know it's a lot) but it also has a 120 to 240 transformer in the basement for the well pump.

 Basically this is an off grid set up that needs several things redone and tweaked. Most pressing issue right now is that the generator will not turn off once it auto starts.

There is no Internet on site and it's like a 3 Hour drive to get there so I'm trying to get some stuff figured out.

The system originally did not have the hub and so the Mate3S was only plugged into the inverter and the MPPT was pretty much running on its own with no synchronization.

Currently we have the generator set in time or mode not state of charge mode which means if it reaches X voltage it will turn on in 24 hours, if voltage keeps dropping and it hits Y voltage then it will turn on within two hours, and then if it hits Z voltage it will turn on within two minutes.
(these are AGM batteries and I'm not sure what the settings should be ideally).
 Once it turns on it will not turn off. Even when it's really sunny in the solar cells are dumping 20 or 30 A DC in.
The generator was turning off on its own in the past with the old battery bank but the settings were so screwed up that we want to start fresh (one of the settings was set to equalize every week at 30 V) 

Basically the generator was turning on and off somewhat correctly in the past but everything else was screwed up and now that everything else is closer to correct the generator turns on and won't turn off. The hub is seeing everything.

mike95490

First, give up on the idea of mixing different batteries.  AGM has different charge requirements than Flooded
2nd - parallel battery wiring  - read this site =  http://www.smartgauge.co.uk/batt_con.html
3rd   Battery EQ is tough on cells, only run an EQ cycle when specific gravity diverges from cell to cell. Weekly EQ has likely cooked your AGM cells

Failing batteries can take a lot of charging, you  may be at the point where the batteries are toast.

What is your generator turn off setting  ?

Joetool

Hi Mike thanks for the reply. I wasn't totally clear in my post; the first thing I did was pull all of the old batteries out and replace them with brand new AGM's that are all in the same date range. Also yesterday spent two hours on the phone with outback installer tech-support. I have been trying to go through the menus on the mate3S on site, and we actually got the online stuff up and running. Turns out the generator was only trying to charge at 2 A. That, and just the incredible amount of terrible work was causing all kinds of issues.
 There's a thing I did as soon as we put the new batteries in with turn off the equalization AGM's don't necessarily need it, and I think the previous 'professional' installer didn't actually know what he was doing.
 The batteries were definitely toast. I'm used to working with Victron stuff and the menu system on the outback stuff is somewhat overwhelming you can actually, it turns out, have settings that contradict each other pretty easily. I really appreciate the quick response

BB.

Just to clarify

2 Amps @ 24 vdc battery bus (48 watts)

2 Amps @ 120 vac (240 watts)

2 Amps @ 240 vac (480 watts)

Not that this is going to change any answers--Just want to show that details matter.

Also, in many system settings, sometimes the parameters are battery bus current (charger dc output) and sometimes they are charger input (120 vac charger block input current).

Charging AGM batteries. If your manual recommends 28.8 {at 77F) charging voltage setting, then from what I have read, EQ charging for AGM would be 28.8 vdc held for 6-12 hours or so once every 6 months.

AGM batteries generally do not need much in the way of EQ charging as cells stay relativity balanced, but mild EQ can help.

You don't want to have the AGM batteries get hot and or vent--That is to be avoided or battery life can be dramatically reduced.

Need to better understand your daily loads (WattHours per day), size of array, battery bank ah and voltage (1,200 ah @ 24 vdc?), location, etc.

Typical starting point is 10-13% rate of charge (10% x 1,200 ah = 120 Amps) for solar and 10-20% for genset charging.

Solar charging current may be higher for locations with poor winter sun with larger array.

-Bill

BB.

Also, regarding genset/charging termination.

For lead acid batteries, we have several ways to end charging

1. Hit absorb voltage set point 2-6 hours (2 hours for 75% state of charge to 6 hours for 50% or deeper charge)

2. Charging current to battery bank falls below 1% rate of charge (AGM should fall below 0.1% SoC).

#1 is typical for solar chargers. #2 can be done with controllers that measure battery charge/discharge current (Midnite and possibly Outback with optional hardware, I think).

And sometimes there can be "magic values" for some settings... For example entering 0 (zero) for absorb time may set zero minutes or it may have a canned routine (i.e., 2/4/6 hour absorb timer routine--Just an example, I don't know the programming details).

Some controllers can be programmed to not do a full absorb charge cycle until batteries below (example) 75% SoC.

Lots of detailed reading required.

Bill

JRHill

Joetool said:

two temperature sensors one plugged into the MX 60 and one into the inverter monitoring battery temperature

Just a side note: You can not use 2 temp sensors. The temp readings fed into either the inverter OR the charge controller will be shared among devices connected to the hub and Mate3s. I do not know the exact downside but my guess is that if the readings between the sensors is not exactly the same/linear, which one is used for adjusting the battery voltages during charging? It may be that neither is used? Who knows? I doubt the system averages them. But only one is to be used.

wellbuilt

 My out back system has the temp sender connected  to the inverter only .
  I allso don’t trust the auto generator start/ stop function , I like to start and stop charging manually . 

    My charging stops after 2.5 hours of absorb if I forget . 

JRHill

BTW, I was looking for something else in the FM manual and noticed this:

An optional battery Remote Temperature Sensor (RTS) is recommended for accurate battery charging. o Only one RTS is needed for multiple OutBack inverter/chargers and charge controller units when the system includes an OutBack HUB and a system display. o When one RTS is used, it must be connected to the component plugged into PORT 1 of the HUB

That pretty much means that it must be connected to the inverter.

JRHill

wellbuilt said:

 My out back system has the temp sender connected  to the inverter only .
  I allso don’t trust the auto generator start/ stop function , I like to start and stop charging manually . 

    My charging stops after 2.5 hours of absorb if I forget . 

Understood but I have to say this from my experience over the years: When it comes to AGS, keep it simple. You probably don't need a bunch of AGS programming options enabled. The more that are enabled the harder it is to troubleshoot a problem. I try to keep it to just one which is the 2 minute voltage start (with lead batteries). In the summer I would enable the Exercise on a weekly basis. Now, with lithiums, I use the Must Run, daily, for 3.25 hrs at 6pm during the no sunlight season. So I'm around at supper to hear it start and connect. Later when we're sitting around trying to find something worth watching on TV I can see the Mate and know when the charge cycle is complete, let it go another 10 minutes, and press Gen > Off. If I fall asleep (wink) it will end anyway. The next morning I set it back to Auto.

The only physical problem had nothing to do with the genset, AGS after market module or OB equipment. It was the cheap 12vdc automotive relay I got on Amazon. I bought a quick replacement from NAPA. It was the same physical size but looked to be a better quality relay. It's worked flawlessly for years. It really has a simple job to do, anyway.

Just recently I found a problem that had plagued me for months. AGS was not working. The genset would start and warm up and when it was time to connect it shut down with an AGS Run Failed. Manual operation worked fine from the Mate. Then I happened across the problem. You can not have the Warm-up time and the Fault Time be the same value. Duh. It was winter and I increased the Warm-up duration but didn't pay attention to anything else. Like I said above, keep it simple. If you have problems or reliability issues its probably something really simple.

wellbuilt

I’m really technically challenged so I have not tried to set up the auto start and don’t use a Electric start generator.
 I use a 2800 watt Honda  it starts on the first pull even below zero . 

   Hey question why are you charging at night ? 

 I charge early morning  but last year I had no solar for 10 weeks . 

 I was thinking about charging at night but have not tried it yet , I’m still getting some  sun here 
  We have a snow storm coming Sunday into Monday so that could end my production for the next couple of months 

JRHill

wellbuilt said:

   Hey question why are you charging at night ? 

We've been off grid for going on 15 years. I've done many experiments over time and most are centered around the winter solstice when we get virtually no solar for the month before and after. Nothing irritated me more than running a generator with only ~500 watts output just to finish the Absorb cycle with lead batteries (at least 4 hours with the L16 Trojans). I even went so far as to buy a small inverter generator so that once the Bulk was done with a bigger gen I would flip over to the small inverter to finish the cycle. It really added to complexity and if something happened to me, the DW is well capable but would have little tolerance. Let alone SG, water, connections, etc. Did this for years. In the low light season I charged in the morning and hoped to Absorb from any solar available, cloud edge or otherwise. Then maybe another run at night.

Then I went for SimpliPHIs. Three at first then added a fourth out of a new love (DW is still primary). I have excess battery capacity. The $ hurt but that has passed. The goal was one generator warm-up and run per day. Yup, I can go for two days with no input. The PHIs could care less. I've never hit low battery cut out. So I didn't have to worry about absorb (6 minutes) or a short charge. So I changed to the time of day to when we used the most power: suppertime, lights on, Sat TV and the TV itself and Sat internet, wood burner fan and ceiling fan and whatever. So I run the generator during that evening time time to charge the PHIs full out and carry the highest loads of the day.: ~2.8+ kW total.

Bottom line it was the batteries. The PHIs are fine whether charged in the morning or evening. They don't care and don't have to be charged fully. But since the genset is already warmed and running another bit to run the highest loads of the day is the best time so those loads are covered and with a full 20aac going to recharging. I get the best possible "fuel mileage" possible.

Lastly: 1) The EU7000is. What a wonderful, efficient, reliable and quiet unit, and 2) the PHIs with virtually no maintenance other than an occasional visual. If something happened to me the DW would have not problems continuing on with little to no technical detail or charges needed season to season.

Sorry to be long winded but you asked (wink).

wellbuilt

O no, thanks for the time .
 It’s very interesting  , I use lead acid battery’s and charge in the am , but I’m sure with no solar input I could charge at nite. 

 I don’t do a full absorb charge every day , I’m at the cabin 3 day a week now . 

 I use about 15% of my battery per day . 

 So one day one I charge for a hour 
 on day 2 I charge for 11/2 hours
 day 3 I charge for 2 hours 
 on day4 I charge to full with 2 1/2 absorb total charging is about 4 hours then I leave for the week .
 I’m going to try charging at dinner and see how it gos . 

 I’m starting to get some sun now , is a week I should be doing better . 

JRHill

Each day there are a few more minutes of sun. Come May I retire the generator for the season, for the most part. WooHoo!

wellbuilt

 May sounds late , I’m done as soon as the snow stops come March I just about done with the generator 
 I start after thanks giving .