First timer going full-bore in Central America

[miahallen]

Great news...my shipment should be arriving on Wednesday and the build will commence immediately. Hopefully I'll have electricity within the next two weeks or so

[miahallen]

Well...more good news. Things are going as planned and I am erecting the solar panel array today. The battery bank & FP-1 are already installed. I should be wiring the house later this week & next week. My updates are difficult however because I have limited access to internet right now. I have been taking pictures throughout the process and will be posting a build log of the system when I get some time.

[russ]

Looking forward to seeing it!

[miahallen]

Here are a few images of the system in progress

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[paulcheung]

Don't put the generator where batteries are, You run the chance to start a fire.

[miahallen]

Thanks Paul...good call. I'll relocate it ASAP

[Will-UK]

Nice equipment.

[miahallen]

Before going any further, I'd like to say a big "Thank you!" to all of you who have helped me learn the basics and step through my product selection process. We have had the system up and running for about two weeks now and we have been very impressed with the power we have available. It has been pretty sunny lately, so having only 8 panels currently up collecting solar doesn't seem to be a major hindrance.

I wanted to ask again about charge rates and where I can learn more about it. At this point, I have decided to run 16 panels (4 strings of 4)...and I think on sunny days it might be pushing my batteries, thoughts? I looked for more sticky type info but didn't find any good reads on the subject, please advise. Thanks.

[paulcheung]

You have 420 amps battery bank at 48 volts. you have 16 panels at 230 watts each. your battery bank charge rate should be fall into C/8 to C/12 which 35amps to 52.5 amps. your panels are producing around 65 to 75 amps depend on the battery voltage and the sky condition also temperature. so if you have about 20 amps load in the house then you should be ok.

Have you get a DC amps clamp meter? you need to have one so you can check how many amps current flow in or out your battery bank.

[miahallen]

So, does that mean that if I'm out on a sunny day and I don't have anything drawing on the system (20A as you suggested)...that I would risk overcharging the batteries? I don't have a clamp meter, but maybe I'll pick one up. Doesn't the charge controller tell me how many amps are being sent into the batteries. Wouldn't the clamp meter just confirm that same figure (approx.)?

[paulcheung]

The charge controller tell you how much it produce, but you have load in the house which draw from the controller. I guess you can work out the difference. I am too lazy to do that plus it changes constantly.

I should have some load in the house all the time when the sun is shining. actually you should try to put all the heavy load on sunny time like washing machine. that is what I do. washing and cloth ironing during sun hours so it won't stress the battery too much.

20 amps over the 53 amps is a bit too much. but if is just a short time and you won't get the name plate amount power all the time, just try to monitor the battery temperature make sure it not too hot.

[miahallen]

OK, a long overdue update is in order here. I ended up putting the PV panels on the roof of my house. 4 strings of 4 into a combiner box in my bedroom and down to the FP-1 from there.

Four panels above my bedroom are facing E by SE at about a 25° angle down from horizontal...they catch great morning sun and remain viable until about 4:30pm (sunset is around 6pm right now).

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Then the 2nd string is on the roof above my kitchen. They are also angled at about 15° E by SE and get great sun until about 2:30pm at which time the roof peaks begin casting a shadow.

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Here you can see both of the strings mentioned above from the ground below.

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The other two strings are on the front porch roof at about a 20° angle W by NW, the morning shadows are completely clear just after 11am and they catch great light until sunset. You can see on the right, a trapdoor a cut next to the window for roof access & as an emergency exit

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Here you can see the view out my bedroom window of the 2nd string.

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This is the combiner box on my bedroom wall...my maximum current should be around 32A @ 120V, and the cable is 8GA and about 20 feet long to the FP-1 below. I'm considering replacing this with some good 4GA next month (cable is already on the way).

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Everything has been running really nicely, and I usually end up using 25-35% of my stored energy each night. So I'm hoping to get really decent lifespan out of these batteries. We've had about 3 multi-day rainstorms come through and so I've probably used my backup generator (running propane) about a half dozen times for about 6 hours each time...seems to be a great system and I'm really happy I did my homework here and bought the right gear the first time instead of cheaping out and not being satisfied with performance or lifespan.

[miahallen]

Just wanted to provide a brief update after 18 months of steady usage. The system has been fantastic overall. On sunny days (plenty of those in Belize thankfully), the system is usually charged and floating by midday, and I've seen up to about 16KWh collected in a day, but there was more available, just didn't tap into it all. On cloudy days however, I've seen as little as 1.8KWh collected in a day (stormy & overcast all day, and a shorter day int eh rainy season). If I get one or two of those days, I usually have to run the generator for several hours to get the battery voltage back up. We ended up getting a counter top electric 120V oven for baking, and it works very nicely. We've used it at night, but it pulls too hard and we decided in the interest of battery longevity, we would refrain from using it if its not sunny out. And that has been working out just fine.

One of the areas I see some room for improvement is that when my water pump kicks in, the LED lights dim briefly due to the voltage hit. I wanted to post about the idea of using a super capacitor to buffer the batter pack and hopefully increase their potential lifespan. In my younger years, I was a car-audio enthusiast, and I always ran large capacitors to get the most power into my amplifiers. Would this be a strategy worth considering? Something like this:

http://www.digikey.com/product-detail/en/eaton-bussmann/XLM-62R1137-R/283-4611-ND/5508996

[inetdog]

One of the areas I see some room for improvement is that when my water pump kicks in, the LED lights dim briefly due to the voltage hit. I wanted to post about the idea of using a super capacitor to buffer the batter pack and hopefully increase their potential lifespan. In my younger years, I was a car-audio enthusiast, and I always ran large capacitors to get the most power into my amplifiers.

The general and informed consensus is that since a super capacitor cannot deliver energy without the voltage dropping as it does so it is not a particularly practical device for this application. There is no way to access most of the energy stored in it if you have to maintain a minimum voltage. Capacitors are great for audio frequencies but not for DC surge currents lasting seconds.
As for your dimming, that is more likely the limitation of your inverter and/or the DC and AC wire size than a limitation of the battery.
Put a fast responding voltmeter on the battery terminals when the pump starts and compare that to what you see at the inverter end and at the inverter output if your lights are AC.