Our solar system

[Mike J]

2 minutes ago, Tommy T. said:

My thought exactly.  Mike I'm wondering if your batteries are charging to 100% during the day?  And if not the pretty much constant overcast weather recently may be impacting it.  

Yes, it charges to 100%.  We are pulling from the grid at night, about 2 KWH or so, and the battery in the AM has never gone below 70 percent.  I think there is a setting that needs to allow it to pull down to 20-30 percent?

[Mike J]

31 minutes ago, BrettGC said:

I'm pretty sure it's a 15kWh battery rather than 5 like yours.  

The panels are 5KW, the battery is 200 amp/hr, 10.24 KWh.  No problem charging battery to 100% even in cloudy weather.   Cells produce quite a bit more power then they did 5 years ago.   That being said, I told the wife that we could always add cells if required.  Another battery is an option but they are really expensive 50K or so.

Edited July 15 by Mike J

[BrettGC]

Lithium batteries can be discharged a lot lower than previous technologies without impacting their performance or longivity.  There's a lot of conflicting and misunderstood information out there and often confusion between percentage, voltage remaining, depth of discharge, individual cells in a pack vs the entire battery pack, terminology and the exact chemical makeup of the individual cells.  

Best to contact your supplier, or even better the manufacturer for advice on that one. If it has been set at a limit, I'd say there's a good reason for it.  

[jimeve]

I have the Hybrid inverter 5 kw (Deye), Panels 3.3 kw and a lithium wall battery 48v 120 ah. Planing to add more panel on the second string facing West.

My batteries go low as 30% my installer insisted not to go lower to preserve the longevity 10 years or more. I need another battery but have to save up for that.

 

Edited July 15 by jimeve

[fillipino_wannabe]

Are you not going to apply for grid tie to sell the excess once the battery is fully charged? The battery will only store 10kwh and you'll produce 30-35kwhs on sunny days.

[earthdome]

19 hours ago, Tommy T. said:

That's another story. I have no knowledge about lithium batteries other than the ones in all our gadgets and computers. I would be cautious with them in a big use like home solar system.

The gadgets use lithium ion which are smaller and lighter. For home use size and weight are not important so a good choice is lithium iron phosphate (LFP) batteries.

[Mike J]

10 hours ago, fillipino_wannabe said:

Are you not going to apply for grid tie to sell the excess once the battery is fully charged? The battery will only store 10kwh and you'll produce 30-35kwhs on sunny days.

No plans at this time to sell back to the grid.  The little bit they would credit (about 5-6 peso per kwh) is probably not worth the cost of the hassle.  Also I think, not sure, that you need a different type of inverter which is more expensive.  This being the Philippines I would not be surprised if a certain amount of additional "off the books" fees required for approval.   We put in the system primarily to reduce our bill and provide power during brownouts.  The less I am involved with PH bureaucracy the happy I stay.

[Mike J]

5 minutes ago, earthdome said:

The gadgets use lithium ion which are smaller and lighter. For home use size and weight are not important so a good choice is lithium iron phosphate (LFP) batteries.

That is what ours is (LiFePO4).  That rascal weighs in at 86 kilo, good thing it is hanging on a concrete wall!  Good for 6000 cycles and still retain 80% capacity.  It should outlast me by a good long time.

[Mike J]

20 hours ago, Tommy T. said:

I had forgotten about rice cooker, air pot, shower water heaters, washing machine, which are big users.

Now that you mention it, I forgot those also.  We are using our induction range top also as we ran out of cooking gas a week or so ago.

[Mike J]

The vendor did a remote reboot of our system settings three days ago.  Since then we have pulled zero watts from the grid.  All of our power has come from panels and/or battery.