First build
Classic 150, Mini PV, Outback 24v 3500 watt inverter
Mistake - mounting Classic in center top of Mini PV . Today I moved the Classic to far left so I can try to install Morningstar Tristar Mppt controller next to it . I am combining an old and new system together ( eventually ) . And as you can see I have not connected anything to the Outback yet. Cold short winter days limit electrical building fun time !
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Nice clean look.
Best get a box around those batteries post haste!
looking forward to seeing your build out as it progresses.
Yes - I am going to build a box around the batteries - almost did that first but not being the best carpenter I decided to wait till I got them laid out so I could measure up exactly how I wanted to build the box. Just me and the critters in there. Someone on the windsun site just told me to worry about the battery cables going through the unprotected knock out hole . Was going to put a pvc on there but wouldn't you know the store was all out of the 2" I needed and bins full of every other size !
Just to show how much I am trying to improve my wiring mess here is a photo of my existing old mess . You can see I really like the Midnite Mini PV boxes - hate to think what it would look like without it !
(//)
Quote from: ClassicCrazy on December 31, 2012, 10:20:34 AM
Someone on the windsun site just told me to worry about the battery cables going through the unprotected knock out hole .
Someone?!?! I'm vtMaps here and there. You are someone else (photovoltaic) at windsun.
--vtMaps
busted !
I see that antenna splitter,
What else are you running?
Hi C C - pv,
And, when you are planning your battery box, it is a good idea to leave a few inches between each battery as well as about the same amount around the perimeter. Insulation can be a good idea, as it helps all batteries to attain approximately the same temp, and therefore that of the BTS. Insulation can cause unwanted heat to be reatained, as well, so this is a trade-off.
CC may be a Hammie Radio type, from the looks of that switch and the Coax.
Looks nice. Have fun with the new hardware. Vic
Yes Ham radio always rules the day here and I apologize because I know I don't have enough antennas up so I am sharing the dual band vertical when I need to - but most of the time it is going to APRS for weather station. Blue coax is going to 80 meter dipole though I have it hooked up to FM radio right now.
I was going to insulate the battery box - right now the batteries are cold zero degrees out and dropping. I thought about putting an electric blanket or something else in there and using one of the Classic aux relay's to warm up the batteries when there is extra power available. I guess I could cut some big vents in there in the summer to make sure it gets proper cooling.
Hi C C,
Great on the antennas. We all always want more!
If you BTSes on all charge sources (can see the Classic's blue BTS in the first photo), and you do not need all of the rated battery capacity, then I would let them run cold. Batteries kept cool generally live longer lives. Looks good. Have Fun, Vic
I am checking into what kind of fuse to put at battery positive cable ( do most people just ignore this fuse ?)
Checking the net there are some very inexpensive 250 amp automotive type sound system fuses but I doubt those are acceptable. There are some $30 250 amp post type fuses rated for DC . Then I remembered I have a bunch of salvaged big fuses - but the biggest is 200 amp. Since the rated input of the Outback inverter is 175 amps I may take a chance that any surges wouldn't blow the fuse.
classiccrazy,
if it were me i'd use what i had and take the chances on possible surges. you can watch what you put on at any one time to avoid high surges. you at least have more than one of them and the worst case would be you'd have to get something rated for the full surge down the road. again just my opinion, but just not politically correct so to speak with most peoples thinking. go for it as it might work out well for you.
Yeah - I did screw one of those 200 amp fuses on today - they are very sturdy and I have another one to switch it out if I need to ( or just eliminate it ) . I won't cry if I blow one of them cause they were free and not $60 or more each .
It was hard to move that cable around today because last night was down to -16 F last night so it was kind of stiff !
C C,
Looks good, and the price was right. Have not looked up the data for those fuses, but probably should be OK.
cpm - Well, there are limits. That is why that conditional -- generally -- was thrown in. Do nothing here to warm the banks, and the last time that I looked, one was 9 degrees C ant the other was 10. They will probably be about 2 degrees C cooler tomorrow AM. There is the issue of correct Temp Comp, and do wonder about stratification, as mobility of the electrolyte must suffer at low temps, I know that mine does! Dunno. YMWV. HNY, Vic
Quote from: cpm on January 01, 2013, 11:14:02 AM
Zero F wasn't one of those some values, more like mid 60s to mid 70s.
But I could be wrong, but my rule of thumb is that batteries like what we
like, temp wise. Where we do the best work, is where they do the best work.
Batteries are just fine down to @-15f (@-25c) but they loose 1/2 of their capacity. My batteries live outside in Missouri and have been fine down to the annual -10-15 max low, but I don't use them much in winter being the summer battery hog. If your in a substained -15 or so you want to watch how far you draw down the battery, since it has less capacity it looses capacity quicker and SG and then you can run into issues.
Yesterday I hooked up the Trimetric meter and last night put the first load on the batteries - it was a bit warmer out - in the lower 20's. I did notice the battery voltage drop quite bit under about 1000 watt load from the inverter - which I attribute to them being so cold. I think the thing to do with the batteries is to build the insulated box and try to warm them up a bit with extra power so that they will perform better in the winter. And of course it would be good to run the big loads on sunny days so that the batteries are supplying so much of the power. Quote from: Photowhit on January 03, 2013, 06:42:02 AM
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Batteries are just fine down to @-15f (@-25c) but they loose 1/2 of their capacity. My batteries live outside in Missouri and have been fine down to the annual -10-15 max low, but I don't use them much in winter being the summer battery hog. If your in a substained -15 or so you want to watch how far you draw down the battery, since it has less capacity it looses capacity quicker and SG and then you can run into issues.
Just the insulating will help keep them warm, the charging warms them and the insulation will help them stay warmer. I don't draw much in the winter so don't worry too much.
Heating uses a good bit of energy, but if you must, hunt the internet for an article about using a AC heat strip, I can't recall it all, but basically they will work with thermostat on DC if you reduce their length in relation to the voltage. Still this is heating with solar, and we all should avoid if possible.
Maybe survive this winter and build a berm shelter for the batteries for next winter.
Just like Photowit says,
The process of charging will result in surplus heat,
The batteries themselves have a *lot* of thermal mass
So, just get them into an insulated box, and you should
be just fine.
no need for additional heat, really.
Just to affirm what the others are saying, unless you are in an arctic situation of deep cold for months you probably are fine installing them in an insulated & ventilated box.
Vents are essential to let the outgassing escape so it does not create an explosion hazard or rot the metals in the box like terminals, cable, etc.
Just from here.
Tom
Check - insulated box will be the next project - getting some amps going into them was the first project - ha ha .
I put my first set of batteries in an insulated box. They stayed warm enough all winter that I could keep distilled water in the battery box without freezing. They got quite warm in that box if I tried to equalize them in the summer though. When I replaced them, I decided to ditch the box. It has been ten below zero here for a week with highs in the twenties. Voltage is a little lower in the mornings, but since we're only 125Ahr out of a 800Ahr bank overnight, I don't need the extra capacity and I'm hoping to gain longevity by letting them run cold.
It is definitely a double edged sword. If you insulate them well they are happy in the winter but unhappy in the summer. While cold just reduces there available capacity at the moment, heat will do permanent damage. I tend to insulate mine and then uncover them in the summer. Mine live in the shop that is heated to 45F during the winter, but can get into the 80's in the summer. I probably worry to much about keeping them warm but they stay 60-70F this time of year just from there own heat.
PS pay no attention to the cables they are temporary as the new Trojans have the terminals turned 90 degrees and I had not made new cables as of that picture.
Ryan
Quote from: Photowhit on January 03, 2013, 06:42:02 AM
Quote from: cpm on January 01, 2013, 11:14:02 AM
Zero F wasn't one of those some values, more like mid 60s to mid 70s.
But I could be wrong, but my rule of thumb is that batteries like what we
like, temp wise. Where we do the best work, is where they do the best work.
Batteries are just fine down to @-15f (@-25c) but they loose 1/2 of their capacity. My batteries live outside in Missouri and have been fine down to the annual -10-15 max low, but I don't use them much in winter being the summer battery hog. If your in a substained -15 or so you want to watch how far you draw down the battery, since it has less capacity it looses capacity quicker and SG and then you can run into issues.
Well battery life is halved for every 10 degree C increase in temps above 25C, and believe doubled for every 10 C below 25 C. My reference had nothing to do with capacity or freezing, but really health. Beyond freezing the battery for its given SOC, I do wonder about other effects, as mentioned -- stratification/electrolyte mobility + the accuracy of the temp compensation during charge. There are limits beyond freeze or capacity concerns.
But am not worried down to about 32 F for the banks here, as they have more capacity than normally needed. Opinions, Vic
Ryan: looks to me like you have a series-parallel setup. The longtimers at Solarpanel talk all advocate avoiding parallel, entirely, based on the logic that the resistance in one leg will be different from another, leading to unbalanced workloads/charging.
What's your thoughts on that point of view?
Well I have always gone with the theory 1 string is optimum, 2 is just fine and 3 is acceptable. Unfortunately there is not always a perfect solution for a particular need in Amp Hours. 2 volt cells make sense and have some merit as if one or two fail you can still operate.
Ryan
Of course a proper battery balancer will make it OK to parallel almost as many strings as you need.
boB
Quote from: boB on January 06, 2013, 10:28:33 PM
Of course a proper battery balancer will make it OK to parallel almost as many strings as you need.
boB
Never heard of such a thing. 'Splain?
My issue here is that I've done the power consumption analysis/forecast for our future home and have deemed a daily use of just less than 1,200 watt/hours per day. Assuming a five-day sunless period, I'd need a battery bank of 1000 AH at 12v, 500 AH at 24v.
My current plan, then, would be to run a 24-volt pack (since the 12v, 1000 amp/hour pack would require a charge current greater than a single controller could produce). The only reasonable way to make 24v at 500 a/h, as I see it, is to slide six 2v-500 AH rolls-surrette batteries in line.
But it would be less expensive to series-parallel 2 x 4 trojan 6v 370 AH batteries, and that would also allow a greater reserve.
Quote from: TomW on January 06, 2013, 10:11:15 AM
Vents are essential to let the outgassing escape so it does not create an explosion hazard or rot the metals in the box like terminals, cable, etc.
Hi Tom, I've got a little nit to pick on that advice. The gasses are not corrosive. What is corrosive is the sulfuric acid mist that escapes from the cells while they are gassing. As the gas bubbles break the surface of the electrolyte they suspend tiny droplets of electrolyte in the air. Some of this mist escapes through the battery vent.
Some folks aim the vents on their battery caps away from the terminal lugs to help prevent corrosion. A better solution is to buy Water Miser vent caps. These are NOT the type of cap that has a catalyst to recombine H2 and O2. These caps have a column of plastic beads on which the mist condenses and drips back into the battery.
Most venders sell only one size, but if you order from the manufacturer you can order one of three sizes. The taller the size, the better they work.
--vtMaps
vtmaps;
Not to be argumentative but..
Just 2 comments;
OK "when / if the gasses recombine they create a corrosive environment". Venting helps prevent this.
I have had terrible luck with those watersavers being more messy than the stock caps and did not see any real water savings and did see a lot more wet cell tops. Used them on 2 different banks with same issues.
Just my experience.
Tom
New and improved - now with 15 minute insulated battery box.
Looks dang pretty compared to my scraps of styrofoam, insulating!
I must have too many cracks in the joints because I haven't really noticed too much difference in battery temp compared to outside air. But a can of Great Stuff spray foam will fix those leaks.
And about the time I get all that done it will be warming up outside and I will want to take it off for cooling !