[screaminchicken80]

Hey guys, I have a few questions I would like to get answered by someone that may have some experience with solar before I go jacking up hundreds of dollars in materials.

First, I have one HFT solar kit @45 total watts. Should I buy additional panels or sell these and get better ones?

Second, I have five Werker batteries @ 12v AGM sealed. Can one panel set charge all five batteries or do I need 4 additional panels?

I am hooking these up in parrallel with the intention of 12 v. Run into a Tripplite invertor. I already talked to an engineer at TrippLite and he stated 5 batteries will work with the unit @ 12v.

So, if one HFT panel set will work, how do I hook it up to charge all five batteries?

Thanks in advance!

 

[makobytes]

Connect your batteries in parallel with each other, then when you are charging 1 batter, you will be charging them all at the same time. The voltage will remain the same. Google a wiring schematic for 12 volt panels in parallel, then follow directions. Very simple. As far as keeping the batteries charged, that will depend on what you plan to use the power for. You must always use less than your system can produce, to protect your batteries from damage.

 

[charliemeyer007]

Your batteries should have a chart showing optimum charging amperage to avoid things like sulfating. I have the HF kit, 45 watts on a really good day is about 3.5 amps. 200 or 300 watts worth of panels would be better for charging the entire bank at once.

 

[Sprig]

... I already talked to an engineer at TrippLite...

I would contact the engineer at TrippLite that you already have connections with to answer your additional questions.

 

[sarco2000]

45 watts is not a lot. But without knowing anything else about the battery bank AH capacity, it's impossible to say.

It all depends on what AH the battery bank is. See if you can find the AH rating (@ the 20 hour rate), then let us know and we can figure it out.

There are much better deals than the HF panels.

 

[WillBkool]

What Sarco2000 said.

I would sell those HF panels and get what you can out of them. You can get a 100 watt Renogy panel for cheaper than that HF kit. I can guarantee that 45 watts of solar will not charge those batteries. Also, you should never have that many batteries in parallel. If you are going to use them like that, make sure to check out this link. Try and use method 3 if possible. With that many batteries in parallel, there is a possibility of uneven charging/discharging of the batteries. But like Sarco said, we need to know the amp hours of the batteries to figure out how much wattage you will need.

 

[screaminchicken80]

Thankfully I figured out 45 watts of power for $130 is not that good of a deal...before I went back and purchased more.

I've been looking panels up on Ebay and will probably go that route since I can get some name brand panels for $.80/watt.

The batteries are used, but have been checked (not with a hydrometer, cause they are sealed). They came out of a university server room and were replaced for preventative maintenance. I'm getting pictures tonight and will put them on here.

 

[screaminchicken80]

 

[WillBkool]

Those are 100 amp hour, pretty nice for free. I was able to obtain some AGM from an old pbx phone system that was replaced by a VOIP system, but I was luckily able to get six and set them up in a 24 volt system. It's too bad that you didn't get six of them.

To charge six of those in parallel, which is 600 amp hours at 12 volts, you need a minimum of 565 watts of solar panels. That is a 5% charge rate and you really could use double that. If that is too much for your budget, you could use less batteries, but it would be a shame to waste them.

 

[sarco2000]

Will is right, and you will need a good MPPT charge controller to charge that battery bank - these are not inexpensive...

But you already have the most expensive part of a solar setup - the batteries.

But 600AH is a fairly large battery bank.

For a bank that size, I would try to charge them at least 60 amps. Charging at less than 60 amps (for a 600AH battery bank) would probably lead to sulfating the batteries, which is not good for them. So we're talking about an Outback FM80 or a Midnite Solar Classic charge controller which can handle the amps.

To provide 60 amps of charging current you will need 60A * 12V (system voltage) = 720 watts / .77 (derating factor of panels & controller) = ~935 watts of panels. More if you use a PWM charge controller. But at this scale you would be better off with an MPPT charge controller.

But anyway, figure on 1KW of solar panels.

 

[screaminchicken80]

Those are 100 amp hour, pretty nice for free. I was able to obtain some AGM from an old pbx phone system that was replaced by a VOIP system, but I was luckily able to get six and set them up in a 24 volt system. It's too bad that you didn't get six of them.

To charge six of those in parallel, which is 600 amp hours at 12 volts, you need a minimum of 565 watts of solar panels. That is a 5% charge rate and you really could use double that. If that is too much for your budget, you could use less batteries, but it would be a shame to waste them.

I can get one more to make six or get three more to make 8 total, but I told my father in law I would save him 3. I will have to go through the other pallets of batteries, because that customer brought in around 5-6000 of these batteries (most all small backup AGMs).

Ok so now I know I need a charge controller, good panels (i.e. Sharp?), and what else besides more wire and roof mount kit?

 

[screaminchicken80]

Will is right, and you will need a good MPPT charge controller to charge that battery bank - these are not inexpensive...

But you already have the most expensive part of a solar setup - the batteries.

But 600AH is a fairly large battery bank.

For a bank that size, I would try to charge them at least 60 amps. Charging at less than 60 amps (for a 600AH battery bank) would probably lead to sulfating the batteries, which is not good for them. So we're talking about an Outback FM80 or a Midnite Solar Classic charge controller which can handle the amps.

To provide 60 amps of charging current you will need 60A * 12V (system voltage) = 720 watts / .77 (derating factor of panels & controller) = ~935 watts of panels. More if you use a PWM charge controller. But at this scale you would be better off with an MPPT charge controller.

But anyway, figure on 1KW of solar panels.

The Outback is a little more affordable I guess? Unless you may know of somewhere cheaper.

 

[screaminchicken80]

http://www.ebay.com/itm/281279514011?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I could drive up and pick these up...anyone have or know about the Sharp panels? Looking at about .72/watt with total wattage of 1250w.

 

[charliemeyer007]

I think those are ok. Less than a buck a watt too. With 5 having one go dark for storm damage reasons you still have 80% and more than enough for batteries.

 

[WillBkool]

If you don't have to pay shipping, then that is a good deal on those panels. You will definitely need an MPPT charge controller for those panels as they are for grid-tie and are too much voltage for a 12 volt system, but not enough voltage for a 24 volt system. Also, if you decide to go 24 volts, then you would need an even number of panels. A Midnite Solar Classic is probably the best, and it will allow you to expand your system later, although Outback, Xantrex, and Morningstar make good MPPT controllers as well.

If you can get another battery, then you could have 3 strings of 2 batteries for a 24 volt system. Make sure the batteries are all the same or else you'll have problems with charging/discharging.

 

[sarco2000]

If you can get another battery, then you could have 3 strings of 2 batteries for a 24 volt system. Make sure the batteries are all the same or else you'll have problems with charging/discharging.

Yes! It would make a 300AH bank, but your stored watt hours would be 7200WH (300A * 24V), same as a 600AH bank (600 * 12).

The reasons to use a 24 volt bank are:
You shouldn't have more than 3 strings or it affects charging/discharging
Charging current will be lower
Current to feed the inverter will be lower
Because of the lower currents, less expensive cable and equipment can be used.

Off the top of my head it seems like this setup could supply 1800WH per day, because 1800WH will discharge the battery 25%, (7200 * .25 = 1800). Not counting inverter inefficiencies. So figure 1600-1700 WH per day with a good inverter.

But it means you will need a new inverter.

 

[screaminchicken80]

If you don't have to pay shipping, then that is a good deal on those panels. You will definitely need an MPPT charge controller for those panels as they are for grid-tie and are too much voltage for a 12 volt system, but not enough voltage for a 24 volt system. Also, if you decide to go 24 volts, then you would need an even number of panels. A Midnite Solar Classic is probably the best, and it will allow you to expand your system later, although Outback, Xantrex, and Morningstar make good MPPT controllers as well.

If you can get another battery, then you could have 3 strings of 2 batteries for a 24 volt system. Make sure the batteries are all the same or else you'll have problems with charging/discharging.

I know 24 v. is probably the way to go, but I can't exactly just shelve this 12v. inverter; certainly don't want to loose money on selling it.

 

[WillBkool]

If you stay 12 volt, you are going to need some thick cables like Sarco2000 said above, but then you wouldn't need an additional panel or battery either. Like most people, it's better to study solar before you buy, but like you, I got a deal on my batteries that I couldn't refuse.

But the proper way to design a system is to first measure your loads, which can also tell you what size inverter to get. Then determine the size battery bank you will need. Then from that you can determine the amount of solar panel wattage that you will need. Don't worry, I did the Ready, Fire, Aim thing too, it's actually what most people do.:

 

[screaminchicken80]

http://www.amazon.com/Outback-FM-80-Flexmax-Charge-Controller/dp/B0091J7UHW/ref=sr_1_3?ie=UTF8&qid=1394564729&sr=8-3&keywords=mppt+charge+controller+outback

Should I go with the FM-60 or FM-80? This is the 80. I'm guessing the "FM-80" is for 80 amps?...doesn't really say in the product details. Also, if I add another (same style, brand, size) battery that would be 60amps?

With regards to the panels, I want to make clear you are telling me to buy either 4, 6, or 8 panels, but have the wattage come out to about 1000 watts?

Thanks

 

[WillBkool]

The wattage will depend on wheter you are using 5 batteries or 6. If using 5, then 1000 watts would be okay, if using 6, then you will need around 1200 watts. Even number of panels are needed if you want to run them in series.

The Outback charge controllers are nice, but I would go with the Midnite Classic 150 for just a little bit more if you can afford it. And it will do 80 amps plus. Midnite Classic

If you go to the link that I provided and look under details, you will find the manual. They sell Outback cc's as well, so you can look at those manuals too.