Off-Grid Camping- Solar Power/Wind Power- Ac, Heat, Fridge, Lights, Etc
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1stDeuce
Explorer
DWH got it right. If you bail to lower voltage a half hour after the charge controller sees 14.4V, you're likely at 80%, and certainly not 100%. Charging to 100% at 13.8v would take several more hours, which you probably don't have on a solar system, unless you're not using it. From the manual for my Morningstar controller: "Depending on battery history, the battery remains in the absorption stage for 3 to 4 hours before transitioning to the float stage." That's how you get the battery to 100% with a solar charging system that gets drained every day, and that's why I recommended the Morningstar controller.
Those are the Renogy specs that I found too. The "four" Renogy stages are Bulk/Boost/Float and Equalize. Night is not one of them, since there's nothing for the controller to do. (Good thing it "recognizes" it though...
)
Note that Morningstar calls the "Boost" stage the absorption stage, which is really more correct. You're trying to get the electrolyte to absorb as much as you can, and the longer the better!
Dropping to lower "float" voltage relatively quickly is ok for a system that sees infrequent use, or if you have too much panel and the ability to get to 14.4V very early in the day, but if you're on it every day, and you don't have an abundance of panel wattage, then you're probably starting every day with 80% battery, which is hard on the battery. (Consider that a solar "day) starts when the sun goes down as far as I'm concerned. )
That "kit" isn't horrible, and I do see now that that charge controller has temperature compensation, but it's pretty easy to do better if you have even just a small amount of DIY ability. Read the HandyBob solar pages and use apply what you learn. He's not spewing BS, and he's not making any money, he's just a slightly crotchety older man who knows what he's talking about.
I suppose if you feel that you must buy a kit, that one isn't bad, just be aware that if it's taking you until later in the afternoon to get to 14.4v on the batteries, you may want to add a second panel so you get there faster and have more time to "float" charge the battery to 100%. If you're only using your setup one or two days at a time, and give it days to recover between uses, then the lack of time at "boost" or absorbtion is no big deal.
Those are the Renogy specs that I found too. The "four" Renogy stages are Bulk/Boost/Float and Equalize. Night is not one of them, since there's nothing for the controller to do. (Good thing it "recognizes" it though...
) Note that Morningstar calls the "Boost" stage the absorption stage, which is really more correct. You're trying to get the electrolyte to absorb as much as you can, and the longer the better!
Dropping to lower "float" voltage relatively quickly is ok for a system that sees infrequent use, or if you have too much panel and the ability to get to 14.4V very early in the day, but if you're on it every day, and you don't have an abundance of panel wattage, then you're probably starting every day with 80% battery, which is hard on the battery. (Consider that a solar "day) starts when the sun goes down as far as I'm concerned.
)That "kit" isn't horrible, and I do see now that that charge controller has temperature compensation, but it's pretty easy to do better if you have even just a small amount of DIY ability. Read the HandyBob solar pages and use apply what you learn. He's not spewing BS, and he's not making any money, he's just a slightly crotchety older man who knows what he's talking about.
I suppose if you feel that you must buy a kit, that one isn't bad, just be aware that if it's taking you until later in the afternoon to get to 14.4v on the batteries, you may want to add a second panel so you get there faster and have more time to "float" charge the battery to 100%. If you're only using your setup one or two days at a time, and give it days to recover between uses, then the lack of time at "boost" or absorbtion is no big deal.
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1stDeuce
Explorer
Except that it only sits in "boost" or absorption for half an hour. You just need a larger solar array for it to work well... Which is part of Handy Bob's annoyances... Everything commonly solar seems to drive the sale of MORE solar stuff to get the system to work well, when really you just need components that work well.
WhileInTheWild
Observer
Actually the specs say it stays at boost for 2 hours not just half an hour so that is at least a little better.
workerdrone
Part time fulltimer
Nice job on the rehab, it's absolutely incredible that you would be able to run any AC at all on a daily basis from 300w of panel, let alone hours' worth - do you know how many watts your Walmart unit pulls?
Rockhounder
Explorer
It pulls about 4.5 amps, but probably double that for a few seconds during compressor startup. If the batteries are not fully charged when you turn the AC compressor on, it trips the breaker on the 5000w/10000w invertor, but if there is about 7 amps showing on the solar panel charging at the time, it will kick over. Basically, anything over a sustained 6 amps or so on the charge controller lets it run continuous, when the sun starts to go down, and we go below 5 amps charge, then we are running off the residual battery power, until our low voltage warning hits at 11 volts. Because the power draw is high, when it does hit 11 volts, and we turn off the AC, the batteries almost instantly read 12.2v or so, which gradually creeps up over the next 10 minutes to about 12.6v.
We noticed that when the deep cycle batteries got a few years old, the performance got worse, to where the AC would only run as long as we had 7 amps of solar charging at the same time. Replaced the batteries, and back to new. We also had to run a really fat extension cord to the AC unit directly to keep wire current loss to a minimum.
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Bluedog225
Observer
Subscribed. Thanks rockhounder!
IdaSHO
IDACAMPER
Someone needs to make a RV evaporative cooler. That would be easy to run compared to even a little A/C unit... I do like your style though, rockhounder.
I doubt many will want to add MORE humidity to the interior of their RV.
Most have enough trouble keeping humidity down to a reasonable level.
1stDeuce
Explorer
In places with humidity, you may be right, but in the arid SW, "reasonable" would be an increase, not a decrease...
I live in Farmington NM. On a HUMID day in the summer, we have 20% humidity. An evaporative cooler might bring 10% RH up to perhaps 20%, or if you didn't flow much air, perhaps 30%!! That would be soooo nice!!
BTW, I did a little search last night and there is a company making an RV humidifier. It's $600, but reviews say it works well out here in "wasteland".
doug720
Expedition Leader
Someone needs to make a RV evaporative cooler. That would be easy to run compared to even a little A/C unit... I do like your style though, rockhounder.
Like these - https://www.google.com/search?q=rv+evaporative+cooler&ie=utf-8&oe=utf-8
I had one for many years in one of our RV's. Worked great unless humidity was too high.
Rockhounder
Explorer
We have an old 16 foot Aljo travel trailer from the 70s that came with a roof mounted evaporative cooler unit. I think a lot of those older travel trailers of that vintage did come with that option. And even earlier, during the 40s and 50s, before compressor AC units became cheaper, most people used the ram air tube evaporative coolers mounted bv opening the window glass a little and sticking out of the window.
dwh
Tail-End Charlie
Yea, 2 hour timer on the absorb stage. That's not optimal, but not as bad as it sounds - there are only so many hours of good sun per day to begin with.
Being temperature compensated also makes up for that a bit, and it can be further corrected by programming in higher voltage set points. It does use 14.4v (sealed) and 14.6v (flooded) as the default absorb voltages, which will also get a bit more work done during that 2 hours than a charger defaulted to 14.2v absorb would, but can have the absorb voltage set as high as 15v.
Which is all well and good - but it appears that that's not the charge controller that comes with the Renogy folding panel kit. This is:
http://www.renogy-store.com/30-amp-charge-controller-p/ctrl-pwm30.htm
http://www.renogy-store.com/100W-Monocrystalline-Solar-Bundle-Kit-p/kit-bundle100d.htm
Being temperature compensated also makes up for that a bit, and it can be further corrected by programming in higher voltage set points. It does use 14.4v (sealed) and 14.6v (flooded) as the default absorb voltages, which will also get a bit more work done during that 2 hours than a charger defaulted to 14.2v absorb would, but can have the absorb voltage set as high as 15v.
Which is all well and good - but it appears that that's not the charge controller that comes with the Renogy folding panel kit.
This is:http://www.renogy-store.com/30-amp-charge-controller-p/ctrl-pwm30.htm
http://www.renogy-store.com/100W-Monocrystalline-Solar-Bundle-Kit-p/kit-bundle100d.htm
1stDeuce
Explorer
That's the one I've been talking about... Dang it, the link to the manual several posts up isn't the right controller. I see now. So the "kit" controoler does 1/2 hour (Not 2 hours) at 14.4 "boost" voltage, 13.6 "float" and has no temp compensation. That sucks for an everyday solar setup.
So as per my first response: Skip the kit, buy good parts.
So as per my first response: Skip the kit, buy good parts.
Yea, 2 hour timer on the absorb stage. That's not optimal, but not as bad as it sounds - there are only so many hours of good sun per day to begin with.
Being temperature compensated also makes up for that a bit, and it can be further corrected by programming in higher voltage set points. It does use 14.4v (sealed) and 14.6v (flooded) as the default absorb voltages, which will also get a bit more work done during that 2 hours than a charger defaulted to 14.2v absorb would, but can have the absorb voltage set as high as 15v.
Which is all well and good - but it appears that that's not the charge controller that comes with the Renogy folding panel kit.
http://www.renogy-store.com/30-amp-charge-controller-p/ctrl-pwm30.htm
http://www.renogy-store.com/100W-Monocrystalline-Solar-Bundle-Kit-p/kit-bundle100d.htm
The solar suitcase comes with "VS1024N" controller which you link to earlier (see http://www.renogy-store.com/Renogy-100W-12V-Mono-Portable-Solar-Suitcase-p/kit-stcs100d.htm). The suitcase setup is $269 whereas the original kit I linked to is $184. As usual buyer beware, but the kit is attractive because it's assumed that the kit will at least work, perhaps not as efficiently as a DIY solution..