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New problem.
Ok. So I ordered and have installed 2 Renogy 100 watt monocrystalline panels with the 30 amp controller. Have a new Samlex 800/1600 watt inverter also. Everything worked great for 6 weeks. No problems and working the way I wanted it. Now I have 2 batteries each with a dead cell. What the hell is wrong with this setup? Way confused. Was using them Labor day weekend for 5 days with no issues. Now I turned the inverter on this Friday when I got to my cabin and it read 12.3 when it read 12.9 the last few weeks at the end of the day. Immediately dropped to 11.7 then just dropped right out. A few people told me I need to keep the inverter on and run some lights or a radio all the time to burn off some stored power so this doesn't happen. A little help.Comment
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Houston we have a problem - and it is deficit charge. Let's start clean instead of throwing things at the wall. NAPKIN-CALC time!
You have 12v / 245ah bank. Running stuff mostly from an inverter, so lets stick to watthours and do napkin calc to at least get in the ballpark.
245ah * 12v = 2940wh capacity. BUT, we're going to cut that in half for no more than 50% DOD:
2940 / 2 = 1470 wh you can play with.
You'll want to get more accurate with all the random loads you are placing upon it. Since we're in the spirit of just picking up things, get one of these for measurement:
P3-International Kill-A-Watt meter. Model P4400 is fine.
Start measuring how many watts your devices use connected to ac power - or perhaps from the genny. Now multiply this by how many hours you use the device daily.
Tally all the watthours from all your devices and make sure it does not exceed 1470 total.
Generally, if you want it to last 10 hours or so, then pull no more than about 1/20th continuous from the TOTAL watthour rating from the first step. In other words, on a continual daily basis, you'll want to pull no more than about 150 watts continuous. Might be time to think about a small lcd backlit tv instead of that monster tube. The Kill-A-Watt will tell you what is the power hog.
Secondary problem even more serious:
What if you DO pull 1470 wh daily from it? How much solar are you going to need from a simple 12v panel setup? Not 200 watts! Breaking out the calc again...
200w / 18v (nominal 12v panel ocv) = 11.1A *best case*.
So, 245ah / 2 (50% DOD) = 122ah needed to return, but since charging is not totally efficient, lets round that up to 130ah.
130ah / 11a = 11.81 hours, lets say 12 hours needed for recharge.
We don't know where you are located geographically, but consider a GOOD solar insolation area that has 4 hours of good sun:
12h / 4 = 3 DAYS to recharge that battery from a 50% DOD - no loads of course either during that time.
This is why your batteries are dying if you take them to 50% DOD, and with your inverters alarming, you are basically taking them *beyond* 100% dod!
Solution is to use the Kill-A-Watt to find out where you can conserve, or replace power hogs with something else. Ideally run no more than 150w continuous or Mr. Peukert will come out of the woods and drop your voltage a lot faster than you'd like.
Unfortunately, it sounds like your batteries are toast, OR you may be able to save them with an EQ charge.
I'd chalk this up as an expensive learning experience. Use the KAW meter to find out what your power budget is. Now choose a proper battery capacity. Now create a solar system that will actually charge that up daily (within the battery specs, like for FLA between C/8 to C/12 charge current). By "daily", this does not mean sunrise to sunset hours. You need to find out what your solar-insolation hours are based on your location, and use that to calculate to try and not "deficit-charge" your bank.Comment
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My location is Sweet Valley, Pennsylvania.
During the time I used the batteries with no problems the inverter was left on for a max of 5 days and it was only on so we could turn stuff on and off throughout the time we are there. Maybe 1 hour of tv maybe 2 hours a day. And all my lighting is led. Mostly running a 10 watt led strip light in the kitchen, a 4 watt led in the living roof. Bathroom 15 watt here and there and one or 2 15 watt led spot lights outside. This can not be too much.Comment
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Also, should I be grounded? Currently I have no ground.Comment
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I had new ones. Stamped on the side. Mfg Date July 2015. That was a comment about someone elses batteries. They have had their used ones with the same set up only a bigger inverter for 2 years now.Comment
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PNjunction----I picked up the Kill A Watt monitor you suggested. I checked the monitor after 3.25 hrs with the tv on and off a few times. I logged .15 kwh was bouncing from 1.0 to 1.57 amps and up to 145 watts. My normal tv usage with a light or 2 on was 1.2-1.50 amps and 110-130 watts. When I turned everything on It ranged from 1.7-2.2amps and 190-260 watts. I don't normally have everything on like that but just testing the monitor to see what actually was being used. After 15 hrs with the tv on about 6 hrs and lights on and off had accumulated .91 kwh.
Day 2 test 16hrs of run time with 11 hours of tv on. Total for day 2 1.3 kwh. Does this help?
This was all with the genny on because at the moment I am waiting on replacement batteries.
Alot of the time we are only running a few lights at about 10-25 watts when the tv is not on.
How many hrs do these situations get me if the invertor shuts me down at 10.8 volts.
Also I bought some 9 watt 12 volt white eagle eye lights that I want to run dusk til dawn when I am not there. Will this do me good or bad? I was thinking maybe 3 or 4 out on my porch. Is this too much to leave on? Will it hurt my batteries?Comment
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SunnyBoy 3000 US, 18 BP Solar 175B panels.Comment
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There is a chart here (http://batteryuniversity.com/learn/a...tate_of_charge) that helps quantitate this.Comment
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That helps a LOT! Now, just get a better idea of what is normal - is 15 hours of tv normal, or maybe just 4 or so?
It is good you checked for worst-case too. Most tend to plan for worst-case, but it is up to you to figure out how many hours is normal, and maybe hedge upwards a little bit or do you want to plan for worst-case. Up to you.
It doesn't matter since now you have the tools not to go below 50% DOD when you size your batteries which is well above that drop-dead catastrophic low-voltage shutoff of 10.8v.How many hrs do these situations get me if the invertor shuts me down at 10.8 volts.
You've got the tools for the watts per hour. But there is a big difference between 4 hours and 15 hours of tv! and some lights. How many hours are you using normally, or are you planning on worst-case with everything on? Basically, you gotta' tell us how many hours you desire.
Well, lets see - 4 lights running 12 hours at 9 watts each is 432 watthours. That is going to to be part of your calculation for your new batteries once you get your tv/lighting hours straight. But if you keep on adding stuff, at some point we'll never get anywhere. TV / lights hours first...Also I bought some 9 watt 12 volt white eagle eye lights that I want to run dusk til dawn when I am not there. Will this do me good or bad? I was thinking maybe 3 or 4 out on my porch. Is this too much to leave on? Will it hurt my batteries?Comment
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Lets say 4 hours of tv is normal. For the sake of this arguement. I did the tests just for the numbers check. Alot of nights we only turn the tv on before bed and set the timer then watch the news in the am. We don't ever have everything on. I just turned it all on just to see what we were using.
Also the 12 volt lights for when I am not there. Is this a good idea? I could use 1, 2 or 3. I was told that I should leave something on all the time that it is better for the batteries to be used a little everyday then only charging/storage. This is coming from a couple guys I see on the weekend that have been working their own bugs out. lol
Lets say I have the 2 100 watt panels and the 2 6 volt 245 ah golf cart batteries in series with the 800 watt inverter. If I run 115 watts how many hours would be a safe run time? And if I ran just 30 watts of lighting?Comment
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Now that you have the tools, we can start here.Lets say I have the 2 100 watt panels and the 2 6 volt 245 ah golf cart batteries in series with the 800 watt inverter. If I run 115 watts how many hours would be a safe run time? And if I ran just 30 watts of lighting?
1) Your battery bank has a total of ((245a * 12v) / 2) = 1470 watthours usable before reaching 50% DOD.
2) 4 hours of tv at 130w = 520watthours. 1470wh usable - 520whTV = 950wh left in the bank to play with. So far so good.
3) DEFICIT TIME with only 200 w worth of panels.
Quite simply, your tv is pulling 130w AC. That means, say for a Samlex inverter, about 13A dc per hour.
A 200w 12v array is only capable of about 11A per hour, and if you had 4 good hours of solar insolation, thats about 44ah returned. But your TV is pulling 52ah in a 4 hour period. Not enough time considering that in reality, about 60 ah needs to be returned daily because charging isn't 100% efficient.
So right here is the problem - forget all the other stuff.
Armed with the Kill-A-Watt, try turning the backlighting down, or invoke the power saver mode and see if you can reduce that TV power load.
Quite simply, to run all the stuff you want to, you will need more panel power, or be much more conservative. And, since we don't know your geographical location, your solar insolation hours are hard to determine if you even have the luxury of 4 good hours!
They are actually introducing bugs, but the feel-good concept might be worth it.I was told that I should leave something on all the time that it is better for the batteries to be used a little everyday then only charging/storage. This is coming from a couple guys I see on the weekend that have been working their own bugs out.
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If you decide to limit your battery discharge to 50%, then you have 122.5 AH to work with. At 12v that is 1470 Wh. But there are some inefficiencies, say 10% to convert from DC to AC. So you now have 1323 Wh. Divide that by the load of 115 watts and you get 11.5 hours. If you decide to discharge your battery more than 50% then adjust the Wh accordingly, or if you have more or less load add or subtract to the 115 watts.
Wh from battery / Watts load = hours of runtime
AH * Volts = Watt HoursComment
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OK. So now what if I add another 2 batteries and 1 more 100 watt panel?Comment
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