2: I think I understand the table. Is "cycle" just another term for a single day's discharge and recharge?
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There's no way you are going to get that accurate an assessment. In cold weather batteries last longer - but have a higher internal resistance. If you have a single string and an excellent charger, they will last longer than if you use a really basic charger to charge 3 strings. If you push them hard when they are cold but let them float when they are warm you'll see them last longer.
It's a charge and discharge, not necessarily one day. -
The major factor in battery life will be how you treat them. Are they overcharged undercharged is electrolyte topped off do they run dry. If the batteries are well maintained then the brand name or type of battery will make a lot of difference In how deep your cycles can be without hurting the batteries and the longevity of the batteries. A little research will pay off here because our needs very And so do our investment abilities.Leave a comment:
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I know a great place to get a $10 AGM battery. It's the Batteries Plus in NeverNever Land, to the left past Bikini Bottom.
I'd love to get back on track here.
I'm going to take this one step at a time. Two questions:200 AH is meaningless without a voltage. So I can only assume you are talking about 6 volt 200 AH golf cart batteries wired in series to make 12 volts. 12 volts x 200 AH = 2400 watt hours. For an off-grid battery system you size the battery to give you 5 days run time. In reality this only gives you 2.5 days as you never want to discharge the batteries more than 50%. Put another way you only discharge your batteries 20% each day.
Battery cycle life and Depth of Discharge is directly related. The deeper you discharge them, the fewer cycles you will get out of them. Here is a chart to display:
Discharge 20% each day and you get about 5 years, 50%just over a year, 100% just a couple of months. In your case using a 12 volt 200 AH is 2400 watt hours and you want to drain 600 watts x 7 hours = 4200 watt hours. Not going to work.
So your air conditioner uses 600 watts and you want to run it 7 hours per day. 600 watts x 7 hours = 4200 watt hours. That means you need a minimum of 4200 watt hours x 5 days = 21,000 watt hours or 21 Kwh. To find the battery AH capacity is easy Amp Hours = Watt Hours / Battery Voltage. So you get:
1750 AH @ 12 volts
875 AH @ 24 volts
438 AH @ 48 volts
To determine cost a good 5 year battery will cost you $220/Kwh and weighs roughly 55 pounds per Kwh. So for a 21 Kwh battery will cost around 21 x $220 = $4620 and weigh in around 21 x 55 pounds = 1155 pounds.
1: So our goal is to get the batteries to last 5 years, right? In order to get them to last 5 years, we'd have to run them down by only 20% of full capacity per day. Is this assuming that you ran them down 20% all 365 days a year?
2: I think I understand the table. Is "cycle" just another term for a single day's discharge and recharge?Leave a comment:
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Results from PV Watts for Lufkin, TX for a 1 kW DC system - a derate factor of 0.82
RESULTS
For Corvallis, OR - same system3.47 83 8 4.37 96 9 4.84 114 11 5.53 125 12 5.45 123 12 5.77 123 12 5.97 131 13 5.91 130 13 5.63 122 12 5.33 123 12 4.01 91 9 3.66 89 9 5.00 1,350 $ 131
RESULTS
2.22 53 4 3.39 73 5 3.32 79 5 5.32 121 8 5.23 121 8 5.67 124 9 6.60 148 10 6.20 140 10 6.01 134 9 3.34 78 5 1.97 44 3 1.63 37 3 4.24 1,151 $ 80 Leave a comment:
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Hey I am an old grey beard wearing glasses using a smartphone with neuropathy in my fingers. If I do it fast it has to do with American motorcycles antique muscle cars or eating.
AbeLeave a comment:
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Yes, I agree I would buy them too. The most I have been able to get at one time is 14. Usually I only get 1, 2, 3, or 4 of them at a time. But for getting started it is still much cheaper than ruening a new set of $300 batteries. My first set was $50 and included 10 $5 50A gelcells. And a broken arcosolar quad lam from the 1970s. They were cracked, look like rootbeer color, and still work fine. They went a long way encouraging me about the longevity of solar. The 300A bank I've used/tested for 6 years is made from four 75A gelcells and cost $40, $10 each. I would love to get 100 of them even if many of them were bad. If someone is looking for a turn key large setup I would recommend they talk to the Kimbell family in Miami Florida. But for anyone small-scale wanting to find out what solar can do I would recommend research and scrounging around. Much better than the $3 per watt for the on sale Harbor Freight set up. Many of my friends were discouraged with that 45W set up.
AbeLeave a comment:
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Hello? Abe? You got info on that $10 battery yet?
Oh well,,, it appears your modem was running on one of them...
Yawn!... I'm going to sleep, with a grin ...
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A requirement for a course I took 2 or 3 years ago was to design a company that made solar panels. We had to know what the equipment was to grow the crystals, where to buy the equipment, The advantages of avoiding contamination by manufacturing our own quartz wafers (made from fused silica), the whole process from raw materials to finished solar panels. Has the industry changed that much in the last couple years?And here I thought that they used silicon (in a high purity crystal) rather then quartz (~silica).
For your own sake refrain from making too many careless or incorrect statements, as it will damage any credibility you are trying to build up.
PS: EMP will generally not affect small scale wiring like the internal tabs and wires of PV panels. Now any that are connected to long wires at the time of the EMP may be a different story. I would say that they are more sensitive to RF (at high power) than to EMP. Do not put solar cells into your microwave. They will behave just as interestingly as CDs.
The RF energy from my radio equipment does disrupt the charge controllers. So far I have not noticed any permanent damage. With me the whole system is about the radios. It is useless to me if i cannot use the radio.
AbeLeave a comment:
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A few easy numbers; 10 amps at 120 volts is 100 amps at 12 volts, both are 1200 watts. If you used 1200 Watts from your batteries it takes more than 1200 watts to recharge them. There is also loss due to wiring, electronic inefficacy, and dust on the panels. Ad in about 20% loss from solar panel to AC output at the inverter if using MPPT charge controller. And up to 50% loss if using PMW charge controller. You will not get the full rating of your panels all the daylight hours. Where I live in Oregon it is 2.9 times my panel rating I get in one day. Where I live in Texas it is five times the panel rating I get in a day. Charts are easily found on internet to let you know how you rate in your area. I've found them more accurate than I first believed.
AbeLeave a comment:
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And here I thought that they used silicon (in a high purity crystal) rather then quartz (~silica).
For your own sake refrain from making too many careless or incorrect statements, as it will damage any credibility you are trying to build up.
PS: EMP will generally not affect small scale wiring like the internal tabs and wires of PV panels. Now any that are connected to long wires at the time of the EMP may be a different story. I would say that they are more sensitive to RF (at high power) than to EMP. Do not put solar cells into your microwave. They will behave just as interestingly as CDs.Leave a comment:
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