walmart & sams club batteries

[ChrisOlson]

So the hot water heater is wired to the sub panel of the inverter and the mx 60 only turns it on.  If It is that simple I love it.  This what you mean?

Yep.  It's that simple.  The water heater is wired right into panel in the house.  The MX60 simply turns it on with a relay using its AUX port - the relay is the switch that flips on the power to the water heater.  The MX60 was discontinued in favor of the FlexMax, and I don't have a manual for it anymore.  I imagine one could be found on the internet to read up on what mode could be used to drive that relay.  From memory it seems the AUX port puts out 12 volt power in diversion mode, which would operate a little automotive ice cube relay, using it as a pilot relay to turn on a larger contactor.  And it also seems it put out PWM on the AUX port which would work with a SSR.  The SSR is a lot easier because it provides more infinite control of battery charging voltage.

Do you have a manual for that MX60?  If you got one look in there under the AUX programming and it should tell you what modes it can operate in, and what the voltages are on its output.

Being you got dual inverters and can stack them for 240 volt, this is really the best way for water heating.  The losses in the inverters are so minor compared to the greater efficiency of 240 volt AC water heating that looking at DC dump schemes is fruitless.  With that 3.4 kW solar array you got, you should be able to pretty much eliminate your water heating bill, and at the same time run critical loads in your house like 'fridge, freezer, well pump and some lighting 24 hours a day, 365 days a year.

Just mentioning this because that setup you got is top-of-the-line stuff.  Dual inverters stacked for 7 kW 120/240 split phase power with a 3.4 kW solar array providing the juice is a real respectable collection of equipment.
--
Chris

[gww]

Chris
I paid $1500 for the inverters, mounting and subpanels, 1-mx60, the 10 port hub,  numerous breakers and mate.  No battery temp.  The guy I bought it from said it came from a doctor who had ten of them going at once and was switching them cause they had a hard time starting his geothurmal furnace.  They look good.  I hope they work.  Do I want 8 or 16 batteries now?

I believe I copied the controller manul off the internet.  I know I did the inverter and mate manuals.

I don't know if I payed proper value or not but if they work I'll be happy.

I can't believe how patiant you have been.  I believe you have really helped me and I thank you
gww

Ps I want 240 volt 2000watt heater elements?  two of them?

[gww]

I am going to have to talk to my furnace guy.  I have gas hot water heat also.  I dont think It draws much water but just cirulates the same water over and over but maby uses some.  While I'm plumbing maby I will take its intake off my current hot water heater.  I have a 50 gal. water heater but only two people living in the house since the kids got married.  again thanks
gww

[ChrisOlson]

Do you have an electric water heater now?  Or is it gas?  If you have just one DWH I'd leave the top element at 4,500 watts and put a 2,000 watt element in the bottom.  Power the top element with grid power with the stat set at 125 and the bottom with the RE system with the stat set at 165 (or as high as it will go).

If you have a gas heater and are going to install an electric as a pre-heater, then replace both elements with 2,000 watt and power the pre-heater from the RE system.  2,000 watts is a good match to your solar array - that's ~58% of it's installed capacity, and on any good day you'll get around 80% of it's installed capacity for output (~2,700 watts).  On a perfect day you should get rated output from it.  On a overcast day the array should put out about 30% (~1,000 watts).

So on a poor day you'll get the batteries charged but no water heating.  On a decent day you'll get battery charging plus intermittent water heating.  On a good day you'll get good water heating.  On a perfect day you'll get all the hot water you can use.

You cannot run dual Outbacks on 8 225ah 6V batteries.  It will take minimum 16 to even get close to rated power from them - and then only for a very short time with no incoming RE power.  You got over 7 kW of inverter capacity.  That takes a serious battery bank if you want to use those inverters.  Putting only 8 batteries on them would be like trying to run a semi truck off a lawnmower gas tank.
--
Chris

[gww]

Chris
My water heater is propane and 16 batteries it is.
Thanks
gww

[gww]

Chris
If I bought more solar or built a bigger turbine I could hook it strait to the batteries and as long as I add enough batteries to not charge them too fast and as long as I had enough constant load on the inverter I could get by with one mx60.  I know going strait to the batteries would bypass any mppt that anouther charge controller would provide.  Does mppt matter if the solar matches the voltage closer to the battery, say 17 volt for a 12 volt battery.  I want to get what I have now going but it is nice if I know future posibilities.  I kind of hijacked some one elses post and I know I may never run out of questions and this could go on for ever so when you decide to quit responding I will still be thanking you cause you did get me where I needed to be. I did get rid of many misconceptions of how things work and feel confedent with being able to proceed.
Thanks
gww

Thanks to all the rest that gave imput.

[ChrisOlson]

If I bought more solar or built a bigger turbine I could hook it strait to the batteries and as long as I add enough batteries to not charge them too fast and as long as I had enough constant load on the inverter I could get by with one mx60.

Yes, that can be done.  The MPPT will give you a slight advantage in being able use smaller wire from the solar array and will operate the panels at peak efficiency no matter what battery voltage is.  But add-on panels can be direct hooked with no problem at all.

I think you'll be happy with 16 of those 225ah 6V's on dual inverters.  That's still on the light side for those inverters because if you loaded both inverters to full load they would have all sixteen of them totally dead inside two hours.  But with light to moderate loads it will work fine and be a good compromise between cost and investment in batteries and being able to actually use the inverters to run loads.
--
Chris

[gww]

Chris
Yes I'm excited to have direction.  I keep thinking about charge controllers.  Pretty big expence.  I mentioned earlier that I had the morningstar on a twelve volt charging station for rarely used batteries.  I just built a ghurd controller with a dumpload so I could free up the morningstar to use with turbines on the 48 volt system.  I have one cc extra now.  It is a versitile one though.  I keep thinking the turbine stalls so compleetly on the 12 volt that I really get nothing out of it.  I was going to widen the gap but now I may try it on a 24 volt system.  The only thing Is I at least thought of a good enough use for twelve volts and can't think of a use for such a small 24 volt system.  I was going to add a leason permanate magnet motor to the charging station also.  I also wonder how would a 3500 watt or a 5500 watt generator would act rectified and hooked to a 48 volt battery bank. 154 volts dc at 23 amps.  would the bank clamp this type of voltage?  I have these generators and was thinking of expermenting with wood gassification or and small batch methene( cow crap).  morningstar may come in handy there.  Maby I'm just crazy but I got the bug.  The turbine is the quickest exsperment but I can't think of any way to use small amounts of 24volt power.
anyway thanks for your help.  I have one direction to go that I believe will work.
gww

[sunbelt57]

#1 variable :offgrid or ongrid?  a real biggie here!
#2 what is your average loads in kwatts per day?
#3 what is your peak load during the day?
#4 what loads can be scheduled?
#5 what is your average charging capability ?
#6 what is your peak charging capability?
#7 what are you using to recharge with, if solar how many hours per day?  how many days of sunshine per week? etc

and there are more ...

the more of these that you can accurately answer, the more information you can plug into established equations, which will then give you a group of answers, like

1.what size bank you will need
2. what will that banks first cost be
3. what will the cost per kw/hr be as related to the battery
4. what will i get in useful kw/hrs per day out of the batteries
5. what will i have to provide to the battery bank each day, and where
will it be coming from.
6. how long should i expect them to last?

and more questions will come up and you will have the information to answer them fairly accurately.

otherwise it is a crap shoot!  and just as gambling you can step up to the table and loose your lunch money.

bob g

I'm doing this off-grid,
Here's some appliances I expect to be using:
   Frost-free refrigerator: 170 kwh
   Frost-free freezer: 188 kwh
   Lighting for 4-5 rooms: 50 kwh
   3-4 water pumps for solar system - 1A/12vdc each using 48vdc->12vdc converter
   other misc appliances (coffee maker, computer, etc)
   I'm gonna say about 500 kwh total?

I'm using (30) flexible solar panels: UNI-PVL 128
I was figuring on buying (32) of the 6v GC2 batteries from Sams Club:
   Minutes at 75 AMPS: 107
   20 AMP Hour Capacity: 208
   4 parallel banks of 8 series

I'm attaching a pdf of the results from the classic sizing tool at Midnite Solar
The avg days of sunshine for my location is around 200/year (WY)
There's plenty of wind but a lot of it is very windy so I'm not sure about using wind.
I also have a 1000 kW gas powered generator which I could use in emergencies (I'd have to be there to crank it up).

[sunbelt57]

#1 variable :offgrid or ongrid?  a real biggie here!
#2 what is your average loads in kwatts per day?
#3 what is your peak load during the day?
#4 what loads can be scheduled?
#5 what is your average charging capability ?
#6 what is your peak charging capability?
#7 what are you using to recharge with, if solar how many hours per day?  how many days of sunshine per week? etc

and there are more ...

the more of these that you can accurately answer, the more information you can plug into established equations, which will then give you a group of answers, like

1.what size bank you will need
2. what will that banks first cost be
3. what will the cost per kw/hr be as related to the battery
4. what will i get in useful kw/hrs per day out of the batteries
5. what will i have to provide to the battery bank each day, and where
will it be coming from.
6. how long should i expect them to last?

and more questions will come up and you will have the information to answer them fairly accurately.

otherwise it is a crap shoot!  and just as gambling you can step up to the table and loose your lunch money.

bob g

I'm doing this off-grid,
Here's some appliances I expect to be using:
   Frost-free refrigerator: 170 kwh
   Frost-free freezer: 188 kwh
   Lighting for 4-5 rooms: 50 kwh
   3-4 water pumps for solar system - 1A/12vdc each using 48vdc->12vdc converter
   Large fans for ventilation and swamp coolers used only on hot summer days for 3 months of the year: TBD
   other misc appliances (coffee maker, computer, etc)
   I'm gonna say about 500 kwh total (not counting the fans)
I'm using (30) flexible solar panels: UNI-PVL 128
I was figuring on buying (32) of the 6v GC2 batteries from Sams Club:
   Minutes at 75 AMPS: 107
   20 AMP Hour Capacity: 208
   4 parallel banks of 8 series

I'm attaching a pdf of the results from the classic sizing tool at Midnite Solar
The avg days of sunshine for my location is around 200/year (WY)
There's plenty of wind but a lot of it is very windy so I'm not sure about using wind.
I also have a 1000 kW gas powered generator which I could use in emergencies (I'd have to be there to crank it up).

[sunbelt57]

Sorry for the double post.
I make a list on the Sam's website and the total comes to $2704 including membership renewal.