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rjj04
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Post by rjj04 » August 17, 2015, 5:13 pm

One inverter??...
Yes, one inverter/charger. The issue for me is that the current system I have provides enough power to allow me to run 24/7 in battery mode during the dry, cooler, relatively cloudless months. If I add more solar, then all that power would be wasted during those months, making the system say 60% efficient. When my batteries get full and I see the MPPT controller skewing the panel voltage up to Voc range, it means I am wasting power... don't like that much. So, it is cheaper for me to supplement my needs during the hot and hot/rainy months by using PEA power. Grid-tie is much more efficient, and if you can get away with it (PEA doesn't lock your meter), then that is the way to go... from a purely financial point of view. Or grid-tie and the PIP4048 with a few batteries being used in UPS mode might make sense... but probably cheaper to get a generator... but a generator is not "uninterruptable"... so decisions decisions.

What might make me decide to get another parallel inverter...
I just got a well put in (45m drilling), and had a Hitachi jet pump installed (30m). It was supposed to be 300W which is what is says on the face plate and spec. When I connected it up to the inverter (running in line mode), I saw that it was actually sucking nearly 600W. That is a big problem for a 4KW inverter as a 600W pump's surge power is probably close to 6KW. Even at 300W it would be a push to get it to run conveniently with the rest of the appliances in the house. For instance, today, it is a sunny day. I had 2 inverter type A/C's running AND a conventional A/C unit running. When all three compressors are going at the same time (as is sure to happen from time to time) that is about 2400W. A 300W on demand pump would probably have a surge to 3KW. The inverter has a surge power rating of 8KW, and this scenario would be pushing on that boundary for sure. The PIP4048 has two modes to deal with overload, an "overload bypass" mode and a "overload shutdown" mode. I certainly don't want my inverter shutting down multiple times a day... then what is the point of it all? :) The "overload bypass" mode is where if the power consumption goes over 4KW, the unit will switch to line mode. This happens even if the 4KW threshold is exceeded for only an instant. This mode is useful for sure (and my inverter probably goes into bypass once or twice a day...it is seamless so you don't know unless you check the data or hear the relay trip), but I don't want it kicking over to line mode every 15 minutes. Now, finding out that the well pump is 600W (which I will complain to somebody about for sure), it is going to screw-up my plans for sure. Every time the pump turns on the inverter will kick over to line mode. That will happen even with ZERO other loads on the inverter. Once in this bypass mode, the inverter seems to stay there (there is no explanation of the algorithm used in the manual) for about ten minutes. This is one issue that might drive me to add another inverter/charger, and batteries in the future. If I do decide to add another inverter in parallel to deal with the above mentioned problem, I may not even add additional solar... as I said... the power is wasted during a good portion of the year. Not sure what to do at the moment. Another possible solution is to automate/synchronize the well pump usage with the inverter/charger. For instance, if automated, I could switch the inverter to line mode, switch on the 600W pump, then switch the inverter back to battery mode. So the inverter would not see the surge power. This requires a lot of time to design and build though.

Off-grid system...
~2600W solar, 3 strings of 3 panels each
strings: (2x275W + 1x280W) SunTech panels, 2x3,295W Schutten (not recommended!!)
A couple of years ago I started with a small grid-tie system. So I had 2x275W and 1x280W Suntech panels already. I suppose I lose some power because the 275/280W string's Vmp point is lower than the 295W panel string's Vmp point, but I don't think it is much of a loss.

-2 banks of 4x12Vx150Ah deep cycle batteries (total of 14.4KWhs @C20 "supposedly ;)
4x150Ah Globatt Inva batteries (1 had to be replaced after two months...so, I would not recommend these)
4x150Ah Globatt Volta batteries (these are more expensive than the Inva batteries but are more closer to the advertised 150Ah @ C20 rating. An experiment I did on the Inva batteries showed that they are closer 100Ah
batteries, and that is being generous)

I was asked not to mention where I got the Volta batteries and what price I paid... so I shall not do it publicly.
Inverter was ordered over AliExpress from MPPT solar themselves.
Except for the Volta batteries, most the rest of the items came from Amorn, which I have to say, have honoured their guarantee a couple of times already.



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Post by JR » August 17, 2015, 6:16 pm

Thanks for your update. Interesting. We are planning on three inverters with a 3 phase system, off grid. PEA graciously offered to pull a single phase cable 1 km to our house for 750.000. I don¨t think so. We look at NC EB deep cycle batteries.

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Post by rjj04 » August 17, 2015, 7:38 pm

750,000 THB??? Or am I misreading that? That's around $25,000 USD... what a bunch of BS. You could build a small house for that much. Is that with Al wire or Cu? If that 1km run is within your property line you could just buy some concrete poles and string a wire up yourself!

As I mentioned before, the quality of the components inside this inverter is highly suspect. Since you will have no PEA line, and will be truly off-grid, I'd definitely have a good generator. The inverter has a gen-set output. I don't have a generator so can't tell you whether it works with the PIP or not. With three phase, I'm not sure how you would wire in a generator? Three phase generator? Three generators in parallel? But then how would the generators create sine waves 120 out of phase... assuming you have some 3 phase loads somewhere? Hmmm. I suppose that you can wire up the outputs such that you can switch/route any phase to any sub-panel, just in case one of the inverters goes bad (certainly at some point). Anyway, I suspect you have figured these things out already. Still, for 750,000 THB you could buy a hell of an off-grid system and not have to pay the PEA a penny in the future. What do they take us "foreigners" for... complete fools ;) Good luck!

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Post by rjj04 » August 17, 2015, 7:47 pm

http://siamcbm.com/product.asp#how

JR, can you share with us where you found these batteries for purchase? It looks like this is a Thai company, Globatt come from Bangladesh I believe.

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Post by maaka » August 18, 2015, 6:30 am

just bought an old suitcase big enough to carry my new solar panels, which I could have purchased in Udon, but is easier for me to just lugg it over, throw it in the back of the tuk tuk / bus, and once in village throw it all together...even taking the screws..hahaha. ....dib dib dib.
this is my second parts trip ( NZ / Thai ) and all but the battery is on site....sounds like Amon will have one of those..where are they located??

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Post by rjj04 » August 18, 2015, 7:21 am

First floor, inside Big-C at the Ring-road/Sakon Nakhon junction.

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Post by glalt » August 18, 2015, 9:42 am

At the house, I am using 4 65 AH AGM sealed batteries. They are in the house so I went for the sealed batteries. They are 2 years old with no problems so far. At the totally off grid farm I am using 2 125 AH flooded batteries. I bought them from a local FB battery store. They were 5,300 baht each 2 years ago. Again, no problems so far except having to add water. The AGM sealed batteries are about twice as expensive as the flooded type. How long they will last is another unknown. I try to never discharge them below 50 percent. Everything I have is 12 volt so the batteries are connected in parallel.

Looking at deep cycle batteries, I check the weight thinking that the heaviest batteries are the best because the plates are probably thicker.

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Post by kubotatim » August 18, 2015, 4:10 pm

rjj04 wrote:First floor, inside Big-C at the Ring-road/Sakon Nakhon junction.
They are actually on the ground floor, as you go in turn right and walk as far as you can and they are there. 1st floor is the Big C store.

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Post by rjj04 » August 18, 2015, 4:54 pm

Not sure where you are from but in the USA the 1st floor and ground floor are synonymous. We are the top dogs in the world now, so... :razz:

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Post by JR » August 18, 2015, 5:40 pm

rjj04 wrote:http://siamcbm.com/product.asp#how

JR, can you share with us where you found these batteries for purchase? It looks like this is a Thai company, Globatt come from Bangladesh I believe.

That website is not updated due to they are looking for a new webdesigner. But the owner is Khun Wuthichai Naothaworn and his email: [email protected]. He also had another with the same before the at and after @siamcbm.com. Rung Seng is the company I have contact with.
He attends an exhibition now at Thong Thani but will be in office from Aug 23.

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Post by kubotatim » August 18, 2015, 6:30 pm

rjj04 wrote:Not sure where you are from but in the USA the 1st floor and ground floor are synonymous. We are the top dogs in the world now, so... :razz:
What????? ground floor is at ground level, 1st floor is one up or it is in the civilised world where I come from,

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Post by rjj04 » August 19, 2015, 12:08 am

glalt wrote:r. The AGM sealed batteries are about twice as expensive as the flooded type.
glalt - Your AGM batteries... does that mean on a Ah basis the AGM cost 4x more than flooded? My flooded batteries are kept inside the house, and I vent the Hydrogen through the wall by a pipe at the top of the room. I built a simple Arduino based Hydrogen sensor that beeps when the level gets too high. I guess one day if that fails and I cause a spark from something I might be in serious trouble :)

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Post by glalt » August 19, 2015, 9:43 am

The brand of AGM batteries is BSB. I bought them through the Internet from Bangkok and delivered to my house. A 65 AH AGM battery is about the same price as a 125 AH flooded cell battery, thus about twice as expensive.

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Post by rjj04 » August 19, 2015, 10:58 am

So, AGM are 2X more expensive than flooded, but apparently they get the same number of cycles at 80% DOD (depth of discharge) as flooded do at 50%.

A flooded deep-cycle might get 1200 cycles at 80% and 2000 at 50%, or 66% more cycles at 50% vs 80% DOD

So, an AGM battery gets about 66% more cycles for the same DoD (greater DoD means more energy can be used, and less batteries need to be purchased to do the same amount of work).

So, AGM cost 100% more but deliver 66% more useful Whs over their lifetimes. For the added benefit of not having to worry about Hydrogen explosions or spills of acid, AGM might be the way to go.

One issue that is a problem for solar with AGM is that if your MPPT charger is slow it can (and often does in my case) overshoot the voltage setting for bulk-charging. The bulk voltage default setting on the PIP4048 for flooded batteries is 58.4V, but on a cloudy day I sometimes see the voltage shoot up to +60V before the MPPT algo can bump the panel voltage up. AGM batteries are much more sensitive to overvoltage issues than flooded and thus might have problems with this.

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Post by glalt » August 19, 2015, 2:18 pm

You're much more of a techie than I am. My charger controller has settings for three different battery types, flooded, gel cell and AGM. The controller seems to adjust quickly to voltage changes. My batteries are connected in parallel as are the solar panels, so lower voltages may make it easier for the controller to react quickly. I won't know which type of batteries are better until one or the other set dies. At this point, it's doubtful that I will expand my systems but if I do I will buy flooded cell batteries and keep them outside simply because of the cheaper price. I think it is advantageous to have more battery capacity than you need because keeping them topped up will prolong the life considerably. Fewer batteries and deeper discharging is false economy. The experts tell us to never mix different types of batteries. It is recommended to keep identical sets and buy them together if possible. Apparently the age of the batteries also makes a difference.

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Post by maaka » August 20, 2015, 6:05 am

thanks guys for the directions...much appreciated.

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Post by glalt » August 20, 2015, 11:10 am

I found this site;

www.solarmateth.com

The price of TBL1600 Double Deep cycle 150A 12V 6,300 baht per unit, Delivery 350 baht per unit and delivered by The Transport Co., Ltd

The tubular batteries are supposed to have a much longer life. I'd give them a try if I needed batteries.

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Post by rick » August 20, 2015, 9:06 pm

Amorn at the Big C had quite a stack of batteries earlier this week, more than i have seen before. So worth a look. I think Globatt and one other brand.

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Post by glalt » April 5, 2016, 10:11 am

I thought I would resurrect this thread. Us solar power tinkerers are never really satisfied with our systems. In my case, I'd like to run the air con in my computer room. The question is if the tubular batteries are better than the flooded lead acid batteries. I have a 40 A charge controller and a 2,500 watt inverter that I bought for spares and the thought that I may eventually build a larger separate system than I already have. The original components after three years are still running fine so I have not needed the spares.

The air con is a 12,000 BTU inverter type. The 2,500 watt inverter should easily run that air con since there is no start surge.

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Post by frankdemchenko » April 5, 2016, 11:59 am

guys,
I would like some help to add solar to my house so I can run my swimming pool filter and take it off the house power. it is a salt water pool and it is required to run 8 hours a day. I know nothing about solar and the more help the better
thanks

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