OK, I have my new system set up but something is not working correctly. I am assuming I wired something incorrectly or I have a short.
I installed the following components:
4-6V Costco (Interstate) GC-2 batteries-wired in 2 groups. (Pos-Neg/Pos-Neg then Pos-Pos and Neg-Neg with the charger leads and the inverter leads sharing the Pos-Pos and Neg-Neg terminals. I also wired a 12V water pump directly off these terminals.
2,300W Powerbright Inverter
Powermax Boondocker 75 AMP charger.
OK, all of these components are brand new. I have them charging off a Champion 2,000 Watt generator. I purchased the charger from bestconverter.com and spoke with the owner/tech who stated this charger would be more than sufficient for my application.
Now, I fully charged the batteries to 12.9 volts on day 1. We went to bed around midnight and around 7AM the inverter shut down. I went and checked and my voltage reading was 10.5. I recharged to full capacity the next day (12 hrs basically) and the same thing the next night.
Last night I disconnected everything but a small 12V fan. at around 1AM the voltage reading was 11.3 and this morning at 8AM the batteries were completely dead again at 10.5. The first two nights we had a small ref running on the system as well.
The system feeds an old camper which I have added a 16x20 addition. The entire load consists of the camper which houses the refrigerator, a few 12V lights , a 12V portable fan and a few outlets that only charge cell phones. The coffee pot and microwave only run when the generator is on. In the addition we have 1 tv,one dvd player, two AC fans and a couple battery chargers for the power tools.
Even if I had multiple items running at once this system should last longer than this, or am I way off in my calculations? The readout on the inverter reads 45 watts when hooked up with very little load.
So could a short be causing excess drain?
What about a faulty ground?
I thought maybe the old distribution panel could be draining it off. Possible?
I am going to buy a Kill-a-watt meter to help troubleshoot but it wont be here for at least a week.
When I complete the house there will be new service panel feeding the house and the system in the camper will be abandoned and use for storage, but until then I have to use it.
you should check each cell of the batteries. when yoi have batteries hooked in.parrellel if one cell is bad the two banks will constantly fight each other to ballance the load which cases them to discharge.this is why in our big trucls we replace all four batteries at the same time. short of getting into the.amp hours used and available it sound like you have a bad battery
That was one of my initial thoughts. I checked each cell and the read the correct voltage. Basically each cell at 6.15 volts then together at 12.3 volts. Then when the tow cells are connected I got 12.3. I will check them again when the inverter indicates a full charge.
sounds like you are testing each battery.
each of your 6v batts has three cells. 2.4 volts per cell. you cant just test voltage as you are just testing a surface charge, it doesnt matter untill you load it. you need to pull the caps and test the specific gravity of each cell with a hydrometer.
i am not the.most well versed person around here on batteries i am just the person with the most time on my hands
I am eagerly awaiting your solution.
I have two Trojan 12v AGM 31s...200 AH total.
I start at 95%..after waiting 20 or so hours from the last charge and i get down to 50% real quick. Only running a computer 4 hours and charging a LED spotlight 1 hour a day, pus not more than 3 hours of 120v 60 watts of lights.
In 15 hours on the inverter I am 50%. I realize the batteries will not fully charge for 10 or so cycles..I am on 7 now, so hope that helps. My AH calculations vs what i am getting are off by a factor of 3. Can it be my house box and wiring suck that much?
The best advice is to go to either Survival monkey.com, or backwoods home .com and ask there.(in the off grid, solar sections)..i am on both forums, and some of those guys have forgotten more than most can learn...That being said, i am setting up a larger system....10 235 watt canadian solar panels, an Outback VFX 2436 power center, and am considering iron-nickle battery bank..This is for a 20x30 cabin!!! .....What my first take is , that the power going out is more than the system can handle.....The inverter itself is a constant draw,,,see what the watt draw is just on the converter(NOT inverting, just in idle mode) See if there are any parasitic loads, drawing power when not in use (indicator lights, clocks, etc.)...if the reefer is plugged in 24/7, unless you have a sunfrost or one of the solar special reefers, that , by itself can be to much...Solar pwer, off grid, is a science....every watt you use must be minimized, and "normal" life, as far as power , does not exist. If you aren't using either CFL's or led's for lights, your done right there....every appliance should be "energy star" at least....And from what i have read, a pump is a MAJOR draw....Not to say there isn't a problem with wiring, short, or ???? but remember, most people on off grid solar will tell you"you need to adapt to your system, it WON'T adapt to you". It is a lifestyle change....Good luck, visit those sites...and plan on spending about $3000.00-1000.00 for a system that will do what your asking....rsbhunter
Here is the best forum I have found for off-grid battery discussions:
http://www.wind-sun.com/ForumVB/forum.php (http://www.wind-sun.com/ForumVB/forum.php)
Go to the Solar Beginners Corner section and post your questions there to get very in-depth and (in my opinion) accurate answers.
Given the list of devices you have listed, my first guess is that you are expecting too much from your 4 batteries.
But only the correct use of your kill-a-watt meter, and some simple math will tell you for certain.
Also, here is a nice FAQ that discusses deep cycle batteries:
http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery Charging (http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery%20Charging)
Good luck...
Randy
.and plan on spending about $3000.00-1000.00 for a system that will do what your asking....rsbhunter
I take it you meant $3,000 to $10,000.
Nahhh
I have spent $1,400 and my system is giving me all want. I have a little problem right now as I described, but that will get solved and likely will not cost anything.
I have adapted my use to my system...that is a forgone conclusion on a small system. if you want to build a big system to either live like you do on grid...or just to have a big system, you will not have to adapt but, as with most things in life can make up for it by spending money.
You machine hogs need to quit feeding info about how complex a system has to be to do the job.
I know that my cheepie inverter draws quite alot of power when it is idle. The cooling fans on inexpensive inverters draw alot of juice. I'm not familiar with the brand you are using, but might be something to consider.
Machine hogs??? The system i'm putting together is a complete off grid system.....i'm 5 miles from the nearest power pole, and at 10,000ft. I don't have the luxury of connecting to the grid.......and i only want to build this system once.....It's not bad to start off small, and build as you can afford...i talk with guy's every week that have done that...but after alot of research, and talking to people who have, and are ACTUALLY living off grid, to the person, they will tell you that if they could have, they would rather have more than needed, than less.....And bring your battery bank down below 50% charge a couple times, and you'll have the privilage of buying new ones.....If off grid is your only option for power, then do your research....if it's just a getaway cabin, then no big deal......but when it's your life, then buy once, cry once.....rsbhunter
You said in another post you had a 3.5 KW genet and were going to get another...4 to 6 K, I believe you said. That plus the solar.
I would not worry too much about having enough juice to run the washer/dryer and the pizza oven.
I do have a total off grid place (not a mental one, but one that exists). Works a lot different for me...hard to see where all that power is going to go with yours, especially since you know about having to adjust your power use off grid...which you graciously gave advice about.
If you really want to make the batteries last, many say do not go below 70%. Better yoet, they will last forever if you don't use them at all.
BTW..no need to get al freaky about DOD greater than 50%. Once in a while will not do anything you are able to keep track of and other things have as much or more impact on life than that.
here is a interesting fact.
50% DOD 1150 cycles.
70% DOD 760 cycles
For me at 2x a week that is 11.5 years vs 7.5 years...assuming I went to 70% DOD all the time. Nothing to get your shorts in a knot over. In 7.5 years I have to buy $400 worth of batteries. You have to do it 4 years later and I live longer not worrying about discharging to..... OMG 80%..
To me off grid means living a bit more frugally, physically and mentally. Different stokes for different folks. That is basically all I am saying. Let's not leave it with the unanswered impression that your way is the only way or the best way.
I know that my cheepie inverter draws quite alot of power when it is idle. The cooling fans on inexpensive inverters draw alot of juice.
Good point...I just read my specs...looks live about 2 AMPS...a lot more than I thought.
In 10 hours the inverter runs draws more for itself than I normally use in a day.
As far as batteries, i'm looking into iron-nickel...said to have a life of approx 25 years, or longer...when they stop keeping a charge at a recommended level, you change the acid in them, and your good to go another ??? years....Like stated, all you need is money (and i'm good at saving ).......i don't tout large systems.....i do suggest figuring on Murphys law, and try to have a 25% overage cushion...so my 10 panels might be alot more than i need, unless i get 3-4 days of snow, clouds, etc, and only a couple of hours per day of sun....Worst case scenario i understand, but, life happens. And there are alot of inverters out there available that are alot better suited for off grid living, instead of the walmart plug my stereo in types, but if thats what you can afford, then til you can upgrade, it's fine....All i'm saying is size your system for your needs, and be realistic about all considerations, now AND in the future.....(and to the generator situation, this one is a gas,small emergency type generator, my real solar charging, backup will be a diesel or propane ) As far as not worrying about 70%-80% of discharge, i would suggest some time is spent doing research on what the honest to goodness people that know these things suggest....websites for Trojan, Rolls-Surrett, and Deka all have guidelines for battery care....True, i can take a 30 watt panel, two golfcart batteries, and a coleman "1000" watt inverter, and light a light bulb......for a while...
You seem to be confusing system size with component quality quality and also making assumptions about the quality of what other people operate...."Walmart pug in my stereo types".
I don't disagree with what you say about sizing correctly. And, with not being too optimistic about power needs and supply. That is pretty basic stuff that most of us with these systems have figured out and done. I, for instance was going to go with four batteries but given my experience with low watt lighting and finding oil lamps satisfactory, did three. I have no pumps, but will have a small fridge. Cost is not a concern as it only adds a fraction of the cost of the build. Just do not need the other one. would not do any harm , but then why not five or six?
Have you actually done any of this or lived off the grid?
Yeah, others do know about all the resources available for info about this..from battery manufacture and others (some on here). And use it too.
Actually, golf cart batteries work quite well.
Have you tried charging the batteries up to full and then leaving them totally disconnected from everything? That can assist in determining if a battery is just plain bad.
Then you need a good meter that can measure DC amperes. Place that inline with the pos or negative battery output. The meter must be capable of handling the DC current of any device you attach to the system. Then try connecting one thing at a time.
My experience has been that old RV's can be a problem.
I have a similar problem on my brand new trailer- seemingly with a 100 amp charger/ convertor, even after 7 hrs of charging off a 6500watt onan generator
Seemingly I can't recharge the batts to full..........
My fridge on propane draws only 1.2 amps which is not much and my batts are only 160amp/hr
I only have lights and the fridge on the 12V - not even an invertor
This summer I'll be going to 4 off golf cart batteries too, and my problem will become worse at 440amp/hr at 12V
Using the RV generator is way overkill for just charging the batts- its sized for 2 AC and full house electricity
Is your fridge a propane one? or an electric one, as they can be power hogs, especially older models.
It looks to me that generator battery charging is not the best, and in my case I either have to add solar- or a second battery charger to run in paralell.
Just to be able to refill the batts after usage.
the RV lights I've since found out are 50w 12V halogens...........thats 4 amps each bulb !
So they will be history and swapped for some LED's, from DHgate ---------0.9watts for the same light output aprox $60usd for 30 LED lights
Its surprising where the current goes !
I had my batts returned to the supplier- the test routine from the manufacturer was charge for 48 hours before doing the test.............thats a hell of a lot of gasoline !
UK.... yes as you have found battery recharging with a generator is inefficient, especially when it comes down to the last 10 - 15% of charge. The final charge takes a fairly high voltage along with a fairly low amperage. Generators use almost as much gas for the final charge as if the batteries were highly discharged. A genset is better at the initial or bulk stage. Solar makes a fine finishing tool where a genset is relied upon for the bulk charging.
And the converter / chargers that come with many RV's suck as you've also discovered. Often their float is too high as well. Relying on a built in RV charger results in more battery sales, IMO.
Does only going to 90% hurt (much)..hardly seems worth it for that extra 10%.
What about a forced 10 amp charge for the last hour (10% in a 100AH battery). I bet that is not optimal, but how much does it hurt the battery, if at all?
Charge to only 90% frequently and the batteries will fail early. Charging to only 90% of capacity as normal practice, will allow sulfation of the battery using the 10% of battery chemistry not reactivated by the incomplete charging cycle. So, yes charging to 100% is worth it, IMO. Not by generator but by solar; also IMO.
Quote... forced 10 amp charge for the last hour...
How much will it hurt the battery? First, it'll use more water so that equals more maintenance. It will probably get too hot with a forced high amp charge when nearly full; that is not good for the battery. Quality PV charge controllers and inverter/chargers will monitor the temperature and reduce the charge if the battery gets too hot. This is to improve battery last. This can be even worse with a sealed battery as the high current and temperatures may cause fluid level to fall, and being sealed water can not be added. Of course anyone can do what they want to, and the odd thing to me is that many folks running off grid really do abuse their batteries either intentionally or from ignorance.
C/8 to C/10 is the usual maximum charge rate recommended for a battery, but that is only during the first stage, the bulk charge. ( where C=battery rated capacity).
Thanks for the reasoned analysis.
Solar is poor option as my side of the mountain is cloudy a lot. I think when I do the tight calculations, it will not be a good deal.
So, I think my next best is a couple more batteries. This way the slow charge is slowly charging more batteries...say 1 amp for 5 batteries vs 1 amp for three. will take as long, but be more efficient. And with that can run genet one in 4 days not 2. I know, now you are going to tell me I need to bring up to charge every day. I'll have to live with not doing that.
I have asked Trojan for their take on this.
More batteries may mean another charger to be able to get the most practical "push" into them. Or is the present charger much larger than needed for the present battery(s). . (sorry if you mentioned those details... I have trouble remembering what everyone's equipment base is.)
Even cloudy daytime skies produce power, albeit in smaller doses. Just the thing for topping up a battery after being given a generator powered bulk charge. But the modules need to be able to produce a high enough voltage with the combination of clouds and summer temperatures.... something that may not be possible without a panel series and an MPPT charger. I have to admit to having many times more sunny days than cloudy days so in the main we don't have much to worry about unless it is darkly cloudy for three days in a row.
Download the Trojan User's Guide? They specifically state "Batteries should be fully charged after each use." Also show charge profile graphs for different battery types.
So going back to the original post
He should have enough battery power - same as my planned bank -440amp/hr at 12V- giving a 220amp/hr working capacity
But I'm guessing the fridge and lights are consuming more than he can return daily from the generator, the same as me
My light consumption came as a surprise, I never would have considered they would have used such high current lights
and they are in banks of 6- thats a huge load for a small battery system.
To me 440amp/hr of batteries should be well sufficient for a small RV-cabin system- the load however needs to be considered.
Reading up on my charger convertor the 100amps is total power, if I have the lights on, radio- that takes away from the charge power- as its 100amps total power - not just charging.
ie if your running the fridge and lights etc while charging you have to discount that from the power to your batts
I think I'll be ading 440ish watts of solar and a dedicated battery charger for solar and another for generator power.
The solar really for the top up, as during the day we have low consumption, nights are really the power hog - watching dvd's with my daughter, but thats also when we run the generator
One thing I was considering, not sure it would work- but rather than have another charger in the system covert mains to the same voltage as the solar panels and just have one large charge controller...anyone tried that ?
Quotebut rather than have another charger in the system covert mains to the same voltage as the solar panels and just have one large charge controller...anyone tried that ?
Attempting to make different sources function properly with the different sources running through one controller is going to cause problems apparently. The same question has been asked on the Outback forum and the user members had reasons as to why it was a bad idea. The info is lost somewhere in the depths of my RAM (Really Awful Memory). Probably something to do with the fact that the voltage from the PV modules can and will vary all over the place as the lighting changes. EG; I've seen out system (Vmp, 28.5 x 3 = 85.5 total) module output vary between 50 or 60 something to over 90 volts, with cold weather momentary peaks as high as 141 volts.
A few thoughts about the original post. I am working through the same thing..kind of. Lots of different possibilities...not all relate dot one another, but any one can be the culprit.
All my thoughts are for genet charging only...no solar for me.
1. I did not get what your total AH was, but running a fridge..even a small one..can drain a lot in 12 hours. Many run 60-80 percent of the time and even 300 watts is 2.5 amps an hour.
2. My batteries go to 80% real quick and then to 100% real slow. This is normal with today' smart chargers meant to save the battery. So you may only be getting part of what you think you are putting in. For me, the total time I will have to run the charger (genet not nsolar) is way long..like 6 hours to get it all done from 40% discharge. I need to figure a way around that. The main problem here is that chargers drop to low amps..say 1-2 per hour when you get to 90-95 %..so it takes a long time for the last little bit. Some say forget the last bit and others say that will hurt batteries. How much it hurts is just a guess. If it drops you from 1000 cycles to 800...for me worth it. i have a call in to Trojan. Charger people..Iota... say its an art form not a science. My solution if not really critical to charge to 100% is to add a coupe of batteries and be more efficient in pumping in amps as genset runs.
3 Reading the batteries with voltmeter will show higher voltage than you have for 12-15 hours after a charge. An hour after will be 0.2 higher or more...so you may be overestimating your charge...see #2 above..
4. I have been told new batteries will not take full charge until 10-15 cycles. I am at about 10 now.
5. My inverter draws 2 amps just to run...in the specs, not measured
A charge controller with a monitor that display PV output amps, battery voltage, and load draw amps, is really instructive. It has been an education watching that throughout the day, as conditions change.
Thanks to everyone so far for the help. I'll add some more detail here. This is now our full time home and due to our location must be off grid. I love it, but don't want the wife to lose patience.
I have 440ah total in the four batteries. I am going to add two more this weekend to give me 660ah. The batteries are new enough that I am hoping they will play nice together.
All components are brand new. The PowerMax Boondocker 75 amp charger coupled with my 2000watt Champion inverter generator is sufficient according to the engineer at bestconverter.com.
I have been through 5 cycles now and something interesting happened this morning. When I checked the voltage on the inverter it read 13.21 volts, previously it had not read any higher than 12.92 (both while on the charger). I have checked voltage with a Fluke multimeter a few times at different voltages and it appears the reading from the inverter is right on.
I bought a hydrometer and I plan on letting the batteries rest today and check the readings this evening.
We are using a small fridge that says 1.5 amps on the sticker. I tried using a timer but the wife wasn't happy when her milk was not quite cold enough.
Our dc lights in the camper may be a bigger draw as indicated. The are all incandescent bulbs and get HOT, so I think there may be quite a bit of draw there.
Ultimately what I would like to do until I can add solar is run my generator in the morning for an hour or so while we make coffee and breakfast and the wife and kids get ready for school. Then use the batteries all day until dinner time. Use the generator for a few hours in the evening while watching a movie and doing some computer work, then use the batteries overnight to power a couple fans. If I can do this I will be happy. My genset only needs about 1 gallon per 8 hrs use. So compered to my old house and lifestyle even and $4/gallon and 8 hrs per day x 30 days a month I am saving a bundle($120 vs $300-$400)!
One more thing. I used 2/0 cable for all my connections up to the inverter. I have never heard this, but is it possible to use to BIG of a cable?
Reading this morning off charger was 13.04 with no load.
Quote from: MNJon on July 24, 2012, 12:21:09 PM
One more thing. I used 2/0 cable for all my connections up to the inverter. I have never heard this, but is it possible to use to BIG of a cable?
No
The bigger the cable the less voltage drop loss. 2GA should be great but $$$ and it may be overkill given the distances involved. It is what you would use in a deep well with a long run. Here are some cable size calculators for DC wiring. I believe that a 5% loss is considered acceptable. Did you mention how long your cable runs were?
http://www.freesunpower.com/wire_calc.php
http://www.freesunpower.com/wire_calc.php
http://www.youtube.com/watch?v=pGL0NgfNGhU
Quote from: MNJon on July 24, 2012, 12:08:42 PM
We are using a small fridge that says 1.5 amps on the sticker. I tried using a timer but the wife wasn't happy when her milk was not quite cold enough.
I don't recall if you have said what type the refrigerator is it. The OP has a reference that the fridge is in the RV section. Is this the typical RV refrigerator or something else? RV fridges are meant to operate on propane or get the electrical power from the power grid; not batteries even if it has a 12 DC option. That is because the RV fridge uses a resistance heating coil to make the heat required to operate the unit.
I am guessing that this is an RV fridge running on 120 VAC from the inverter. In that mode the small ones, 2 to 3 cu ft will be rated at around 1.5 amps. That's 180 watts. And I'll be surprised if it does not run more than half the time, maybe up to 80% of the time, even more. 180 watts for 20 hours is 3600 watt/hours. That the AC watts, no accounting for inverter loss. That could be more like 4000 watt/hours with inverter inefficiencies. That is more than what we use in three normal days at our cabin. But then we burn propane for the refrigerator.
Four 6 volt 220 amp hour GC batteries wired for 12 VDC output have a total capacity of 440 amp-hours at 12 VDC which is equivalent to 5280 watt/hours. The fridge alone is enough to deplete the batteries in one day.
That's a guess so may be a total waste of time.
What exactly is the refrigerator?
MNJohn, if possible, look into adding solar as you can afford..As this is your primary home, this needs to be a long term solution..if you have the solar exposure, it will work all the time you have sunlight....I know it's expensive, but when you buy the componets, make sure you get what will handle the voltage that your system will run on, 12, 24, 48 volt. I have mine in 24 volt as the wiring can be smaller gauge, it has less electrical loss in wiring, and from what i have learned, it is more effiecient as your voltage goes up....But, other than that, it might be worth checking into a 120 volt "energy star" small reefer...some of them can really save some power....please look into some of the other forums that deal with off grid energy production.....they will give you a load of info...not that the people here aren't willing, but it really is a complex issue , if it is to be your primary power source...and contray to alot of comments, it is NOT cheap, if you want reliabilty and longevity off grid.....rsbhunter
Quote from: rsbhunter on July 24, 2012, 01:29:45 PM.... contrary to a lot of comments, it is NOT cheap, if you want reliability and longevity off grid.....rsbhunter
Yes. It is not cheap if there are more than a minimal number of lights and not much else. And cheap, or inexpensive, can be different for different people.
I still consider the approx $8 to 9K we spent to be a very good deal compared to the $55K to connect to the grid. There was also a 30% tax credit that helped with the cost of everything from the PV panels and the bolts that connect them to the pole mount, up to but not including the cabin electrical service panel. We were also fortunate in that our state, NM, exempts all components that make up the solar system from any sales taxes.
Cheap or not cheap is another subject..really depends on what you want and need. For a complete system to run a lot of stuff..like a "normal" house, $8K is not a lot IMO, but for me 3K would be a high end system and I need no more. Low cost does not mean cheap components or not enough power. There seems to be a lot of confusion about that.
But all that aside, you need to solve the existing problem first...that may affect you no matter what system you have. Now is the time to do it...the less things you have in the system the easier it is to ascertain what is the problem and the more flexibility in fixing it. I have a bit of the same thing and am doing that now. I think my system is OK, just that charging the last bit of amperage is a long process and runs the generator a long time for the last 10%. I will gate that sorted....think needs a few more batteries.
From your last post, it seems to me that you are relying a lot on your generator...if this is a full time house, that may get tiresome and solar sure looks like it is the way to go. I need to run my generator twice a week for 3-4 hours..or maybe once a week if I get a few more batteries which I think will solve my current problems with slow charge at the top off by making a longer generator run (but less often) a lot more efficient because it will be charging 5 batteries not 3.
But my power requirement are really different than yours...lights which are all low wattage (I can light my place up with 60 watts) and a small fridge, plus a bit of computer charging. So while solar would be really nice, it is hard to justify..although I do hate the genset noise...and I have a lot of clouds. I need to do a good sun analysis to see just what it would take to build solar in.
Here is what i am doing to isolate and ID my problem.
1. I talked to Trojan and the tech rep is going to get mack to me with the real deal on how much charging to 90% will hurt the life of the batteries. If it takes me from 1000 cycles to 900, that is OK and I think from my preliminary work that will go a long way to solving my problem.
2.I am going to fully charge the batteries..until the IOTA charge light indicate float for at least 4 hours. Will pull the batteries and charge them on the grid for this. Will wait 12 hours and check the voltage to see if it jibes with the 12.84 volts Trojan say I should have. From this, it looks like my batteries have been charged to about 85%, since my open circuit voltage after 12 hours has been 12.75. If so, that is my problem and the solution is available.
3. I also am going to run my inverter for 24 hours with nothing hooked in and not connected to the house box. Want to see how many amps that uses. If 50 amps as I suspect it is, that is yet another problem to deal with. That is 25 to 40 percent of my battery capacity just for the inverter. I do turn it off a lot, but still an issue. I need to see about lower amp users.
4. Finally, I will run my inverter connected to the house system for 24 hours just to see how much i lose there with just the wires and not lights, etc. If vetting is done right, should be next to nothing...but who knows.
5. I also need to cheek my genet to see if it is giving the inverter what it needs to charge at capacity. There is some thinking that non-sine wave generators cost a lot in efficiency...like a 20% loss in power front he charger. Not real sure how i will do that yet, but should be a way.
Anyone know a meter that can check the amps running through a line.. My multimeter is limited to 10 amps and that will not do. That would sure be useful. have not been able to locate a user friendly one that cost a reasonable about.
Meters (http://www.bogartengineering.com/)
I didn't think my cable size was an issue, but I am stumped. I thought the 2/0 was overkill, but at only an extra $ .30 per foot I thought it was a no brainer, especially if I was going to add capacity. My cable runs are short: 12 inches batt to batt and 36" batt to inverter. Right now I have them in a vented plastic deck box, but will be moving them inside to a vented closet before winter.
My fridge is a small residential fridge with freezer, and yes, it runs A LOT. I am going to replace it very soon. I looked at the energy star full size fridges and was apprehensive to buy one because I am afraid it will be too much of a load, but it sounds like it may actually be an improvement. Especially if I take alextrent's advice and put it on a timer. I would rather go this route than propane the more I think about it because if when I add solar the electric fridge should be fine.
I can connect to the grid, but at a cost of $23K for the privilege of paying a monthly bill I will pass (actually I have to pass as I don't have the $23K in cash, and if I did I would not give it to them!). In comparison I have paid:
Generator $499
Batteries $79 each x 4 (two ore coming this weekend)
Inverter $199
Charger $199
Cable and misc-$100
Plus a future $3K for 1KW solar setup for a total of approx $4,500 (not including tax credits). A relative steal!
MNJon...Solar can save money from grid tie, a break even, or even a small loss situation, even figured over years. You will find that most who are off grid are there because of expense of hooking up to grid..i know it would run way too much for myself, as i am 5 miles from the nearest pole.....If you're young, and you buy a system sized for your needs, you MIGHT save money...but don't plan on it. If this is your main living quarters, and you can honestly live with a minimum of elect. use, then you might get away with $1000.00 to $2000.00 system. When you start buying the componets that are the best suited to long term off grid use and high effieciency, they are costly.....Look into Morningstar, Outback, and the others that are in the buisness of serious solar and wind-hydro...Also, PLEASE try to get an issue of Home Power magazine (mostly solar info)...or a subscription...it is worth it's weight in gold for the infomation it has...My system is probably oversized quite a bit, but as this will be my only power source, and it is where i will stay when i retire, i need to have a 98% reliable system....I need to spend the money now, while i'm earning it.....rsbhunter
As a note, do a search on google for energy star appliances, there are charts that show the different "tiers" of energy star ratings, and the average yearly use in energy....rsbhunter
Personally I don't believe you can run any refrigerator on 4 GC batteries. No matter the type of fridge it draws too much power. A Kill-A-Watt meter would confirm that I am certain. I don't see a timer being of any use; it will simply force the fridge to run full time when the timer says "OK" and leave you with food that is warmer than it should be, IMO.
I believe your assessment of a std size energy star fridge being too large a load is correct. Too big for your system. You could look into converting a chest freezer to a fridge, but that only works if you can live with a chest type. I really don't like them. Or spend money for one of the Sundanzer's; but again they are chest types.
Mountaindon, you are 100% correct....Although i do have a friend in Az. that is running a reefer and freezer on solar and wind.....BUT....he has a much larger battery bank, more panels and is VERY aware of monitoring the status constantly.....I have been on the phone with him when he's said"gotta go, need to start the generator" cause of low batteries!!! He also turns off the power to the fridge at night (around 10:00 PM) and when it comes on in the am, "normally" it's daylight, and the panels are producing enough to cover the additional power needed to bring the fridge to normal temps...but he states that the inside temp never reaches even close to a to warm temp....So each situation is different....Off grid is not a plug and forget lifestyle....but , there is a feeling of "freedom" if you can make it work for you...rsbhunter
my semi truck has four 1200 amp interstate batteries and if i leave my mini fridge running when i come home the batteries are dead on the second day.
I think I am going to purchase four more batteries this weekend for a total of 8 batteries and 880ah, with the intention of adding solar next spring. Until then I will use the generator and the 75 amp charger to keep them topped off. I will probably just have top go with the most energy efficient fridge I can afford and use a timer and figure out a system/schedule to keep everything safe. Fortunately we are in northern MN so I can set my stuff on the deck in November and it will stay frozen til April! That should help with my refrigeration.
I still think the old rv panel may be causing my excessive discharge. I am going to research it and abandon the rv components ASAP.
Here is what i am doing to isolate and ID my problem.
Step one is complete..
Charged on the grid for 5 hours and got 12.84 volts on both batteries after a three hour wait...so they are charged to 100% as per specs. Took five hours. In 12 hours of sitting idle charge was down to 12.77 and 12.80 on the two batteries (12.62 is 90%) so this is very high 90's. Charged again for two hours and after three hours back to 12.80 and 12.84.
I estimate that I am at 90% (12.62 in about two hours of charging from 50% which is reasonable for me. That is what i will do rather than doing another 3hours for another 10% to 100%.
Trojan tech rep says OK for a month of twice weekly cycles like that and then equalize. I need to figure out how to get my Iota to do that..it is automatic after seven days on float, but mine will not be hooked [p continuously that long.
Next I am going to sort out the inverter draw and if my house wiring is robbing any (too much).
Step two of my test to see what ails my system.
Was either bad batteries or some big current draw.
Batteries are OK. Sixteen hours after charge reading right at 100%. Batteries OK,,,three Trojan AGM 31....300 AH
Next step is to find the current draw. Suspected my house wiring.
Wagan Proline 3000 inverter.
System feeds from inverter to house box.
For the test I disconnected it from the house box so if a problem there it would be isolated.
On the batteries and no load, from the meter on the unit:
A. Voltage reads true to what my multimeter say.
B. Amps are 25 to 30 onn inverter meter and not way for m to check this.
C. Watts out 250-350. Also on inverter meter and again not way to check.
So, this means under no load the inverter is pulling 30 amps. Specs say 2.
I also tested it under load with a known wattage device and the total watts (measured with Killawatt was real close to the inverter alone reading as above and the device, so this is not just a no load anomaly.
Got message into Wagan.
Running inverter no load on one battery and will measure in an hour to see if took battery down 30 amps fro the 100 full charge. If so, bad invert I guess.
My situation is so similar to yours. My inverter meter was reading the same voltage as my Fluke meter everytime I checked. But with no load the inverter still said 25 amps. I will have to do some more research on the inverter as well. I know some others have stated that some inverters can be a big draw.
On another note I purchased four more batteries but before hooking them up I tested all 8 batteries with a hydrometer. the new ones read 2.75 and the original (still new) ones did not even register. SO this explains most of the extremely fast drain. i dont know if I got a bad batch of batteries or what happened, but I will be exchanging them next week. I think I will only connect 6 however and use the other two elsewhere since 6 seems to be the max advised to use in a 12 volt application.
Keep us posted alextrent. I followed your advice closely when setting our system up so I am curious to see your findings.
I ran the inverter with no load for 4.5 hours total. Batteries came down from 98% to 80%.. The 80% was measured after 1 one hour rest from any inverter load. Just as a note, batteries went back up from 65% measured immediately on inverter shutdown. I figure the rested load is the correct one to measure.
So, in 4.5 hours my inverter used 4.0 amps per hour. Specs say not more than 2 amps for the inverter. The meter on the unit continues to say it is drawing 30 amps, so this is not accurate at all. Since I am doing this on a single battery, had that bee the case i would be dead in three hours.
I did this in stages 2 hours on...rest 1 hour...1 hour on....rest 1 hour and then the final 1.5 hours on (actually a bit less than 1.5 here). Measured after each stage (at one hour rest) and pretty much the same draw in each stage.... 4 amps.... a lot better than the inverter meter says but still way too much.
Wagan has not returned my inquiry yet. They may have a reason for meter reading and I am also eager to hear comments on the no load draw.
If I were running a big load, this would not be particularly irksome as the 4.0 amps of the inverter would be a small percent of the load, but my loads are small...on the order of 10 amps max, and more like 5 most of the time, so this is a big percentage.
I have another smaller inverter here (1500) watt, also a Wagan and will run this test this AM on that one. This one says less than 1 amp inverter draw.
Have to read my previous post to have this make any sense.
I put a smaller inverter (1500 watts) of the same make..(Wagan) on a fully charged and settled battery.
Ran it 8 hours and after shutting down and letting the battery rest 1 hour...used 8 amps or a bit less...so 1 per hour or less. Specs for this say less than 0.9 amps.
This is by calculation from starting and finishing voltages as read on a multimeter. The inverter has no meter. So this is subject to some error as 0.12 v on the meter is 10 amps, and a slight error in reading the voltage can be 4 or 5 amps. Nevertheless this is close...a bit better or worse, still in the ballpark.
So, at this moment, looks like my big inverter is off the mark. Been used pretty hard outside in the dirt and rain. Waiting to hear from Wagan...two emails from me and still waiting...two days fom the first. I have place i can but one and return it...think I will do that and test it new and if bad take back.
Made in China...at least I did not use it for food or animal feed.
Still no reply from Wagan and they did not answer the phone in customer service..got a message.
I talked to a guy here who tested his draw by the inverter in no load...supposed to be less than 1.5 and is 6amps by his meter. None of us here have separate amp meters so we have to rely on the inverter meter (next States visit I will buy one). He was very taken back...never occurred to him to measure since he has a big solar system which keep hum topped off most of the time..likely runs his genset 15 time a year.
Is this a generally big problem or just happens now and then...mine has been used hard so that may be it. My little one is right on the specs.
I am not thrilled with Wagan service but there is a place here with them in stock and a good return policy so I am going to buy a new one and see if that draws specs or higher and if higher we know it is the design.
MNJON..did you have a meter independent of the inverter to test your draw?
I dont have a seperate meter. I will be adding one though.
I have another question. My inverter will not shut down until 10.05 volts. Where can I find a device to shut it down at a higher voltage (80%).
I hate to state the obvious, but, it seems the answer seems to be to go DC for a small off grid system.
And, what's so bad about a propane refrigerator?? I remember natural gas refrigerators, which were common when I was a kid in the 50's. Auto defrost hadn't been developed yet, but the rest worked fine.
http://www.backwoodshome.com/articles2/yago102.html
DC refrigerator for off grid writeup
Well, it actually is not so obvious. Yes there are some advantages. Some with 120 system too.
For me the challenge is getting the 12v system stuff where i live. Hauling propane tanks is is also a problem. And with 120v i can just plug in all my existing stuff...tools, etc.
Other things as well. i am sure others will tell you what they are.
On a different note, having a system problem (like the inverter one I have) is not the end of the world and is ready solvable..already solved actually. If something doesn't work you don't just run away and blame the system when it is a part of it and a natural part of dealing with mechanical or electrical systems. I had a BMW and when i got a flat, my neighbor said (with all seriousness) "should have bought a caddie". Same thing here.
I am using my smaller inverter....1,500 watts. Can see the difference already. Was on about 15 hours over the weekend and the difference in the less than 1 amp idle draw with this and the over 4 with the big one is night and day on DOC. On my small battery system that is close to 15% of the total amp hours. Still no response from Wagan tech service.
Before we click on the "post" button we should all think about what we have typed. If your message contains remarks that could be construed as a "personal attack" then you should edit your message before making it public. Not to say that we can not disagree with a statement by another member. However, it is definitely possible to be polite, civil and tactful when disagreeing with the point of view of another member.
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I want to echo what Don says...
Before you post ask yourself if something you have typed might be construed as too personal or an attack - even if you didn't intend it that way. Forum postings don't have all the indicators such as voice inflection or physical body language that we use to express things we want to say.
Then, knowing that, it helps to have a bit of a thick skin and give the other guy a bit of slack. They might be having second thoughts as well.
Finally, you can always edit your post. Sooner is better but later is still better than saying something you might regret.
First, thanks all for the help. Also thanks Don and John for the call for civility.
Now, I have replaced the original four batteries with 6 6 volt gc's. Do I connect them as follows:
I have 6 6V 220 ah batteries that I am connecting to make a 12V 660 bank. Do I connect +/-,+/-,+/- then +/+ on sets 1 and 2 then -/-on sets 2 and 3, leaving the - on battery 1 and the + on battery 6 open for the charger and inverter leads?
3 sets of two batteries in series and then paralell them together if your doing a 12 volt system
series- voltages add together- amphrs stays the same
paralell - voltages stays the same- amphrs add together
so if you have the 6 batts 6v at 220amp/hour
you should get 12 V at 660amp/hr
I tried to draw it with letters, but failed miserably
In words then
You build three set of two six volt in series. Then connect the three end positives together and the three end negatives together at the other end
+ battery one, battery two-
+ battery three, battery four-
+battery five, battery six-
Can't figure out how to show it but all the + connected and to + side of charger or load
And all the - connected and to - side of charger or load.
HTH baby
Gotcha. I was missing two connections. I don't know why it eluded me, but you know sometimes you can't see the forest for the trees. I had missed the - connections on 5-6 and the + on 1-2. I thought it had to leave the terminals at the opposite ends open for the inverter/charger leads, just like when you look at a battery you have one open + and one open -. It read proper voltage.but as soon as there was a load it dropped to 10.11 volts within 30 seconds, then when I removed the load it shot back up to showing full charge.
FYI, I spent almost 30 years self employed in the auto electric field.
I have owned the first item for over 25 years. The supplier has a reputation for cheap. My meter was inexpensive, if you get the nuance
The cheaper one was adequate for quick checks.
I admit my inexperience with battery arrays like you use. On car's the conventional wisdom was to disassemble and check separately.
http://www.harborfreight.com/100-amp-6-volt-12-volt-battery-load-tester-90636.html
http://www.harborfreight.com/500-amp-carbon-pile-load-tester-91129.html
Using buss bars makes for a neater installation. Also makes it easy to remove a series string for any reason, without disturbing the others.
3/16" x 3/4" solid copper was used; size it for the needs of your own system
(https://i133.photobucket.com/albums/q75/djmillerbucket/jemez%20mountain%20property4/P1010479.jpg)
(https://i133.photobucket.com/albums/q75/djmillerbucket/jemez%20mountain%20property4/P1010478.jpg)
Very nice and neat layout Don! You might think of getting some rubber strips and gluing them on the top of the bus bars. Nothing fancy, just something to prevent
the dropping of a wrench from ruining your day.
Bruce
Since those photos were taken I've slipped foam pipe insulation sleeves over the buss bars. :) "Mr. Sparky" visited me one day and I said to myself "That's enough of that". The wrench has a little burn mark now. If I was setting it up again I'd space the bars a little further apart. At the time I had that scrap piece of plywood just laying about and so I used it.