dwells
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Post by dwells on Sept 6, 2014 15:31:18 GMT -8
If you have solar to charge controller and charge controller to battery, will it in any way affect using 12 volt items connected to the converter? This is with no shore power so no charging of battery from the converter. Is it safe to assume that it won't interfere because the converter is affectively bypassed? Actually now that I think of it here's a sub-question: if you're connected to shore power should you have the charge controller from the panels disconnected at the battery? Obviously I don't know all of the ins and outs of how a converter functions, just a basic understanding of it. By the time I'm actually hooking all of this back up I will have done much more research (this is part of that research).
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howard
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Post by howard on Dec 10, 2014 19:46:11 GMT -8
My question, exactly. Hope some old pro will answer. H.
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Post by vikx on Dec 10, 2014 21:41:02 GMT -8
Solar technical questions would probably best be answered on a board geared toward RV solar power. While some of us do use solar panels, there are many different configurations. Smaller vintage trailers often use a less sophisticated system without a converter.
Most higher end systems have checks and balances to keep all working as it should. (diodes, solar friendly components, etc.)
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Post by bigbill on Dec 11, 2014 0:33:56 GMT -8
Solar technical questions would probably best be answered on a board geared toward RV solar power. While some of us do use solar panels, there are many different configurations. Smaller vintage trailers often use a less sophisticated system without a converter. Most higher end systems have checks and balances to keep all working as it should. (diodes, solar friendly components, etc.) Don't we have a fairly large post on here somewhere that got into some of the solar power stuff? |
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Post by vikx on Dec 11, 2014 10:33:00 GMT -8
Yes there are a couple of solar discussions but they don't delve into the technical aspects above.
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howard
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Post by howard on Dec 16, 2014 16:55:48 GMT -8
Hi Dwells,
Go to handybobssolar. Lots of good stuff there. He says that nothing blows up, if you hook solar, and a converter, up at the same time. My guess is, that both chargers will do what they are designed to do to the battery, whether it's efficient, or not. If anyone thinks otherwise, please let D and me know.
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cowcharge
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Post by cowcharge on Apr 29, 2015 14:09:47 GMT -8
I know this is an old thread, but yeah, you can have your CONverter and solar panels hooked up at the same time.
I used the abovementioned HandyBob's "The RV Battery Charging Puzzle" as my bible. Here's what he says about multiple chargers, lol (he gets a lot of questions more than once): "Also, please stop asking me about disconnecting one charging source when another is working. There are thousands of motor homes going down the road with two and three chargers all connected at the same time. They push against each other, but nothing blows up."
The really dangerous thing to do is to connect an INverter's output to your interior 110v wiring and then hook up shore power.
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gina
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Post by gina on May 6, 2015 6:06:38 GMT -8
Your solar controller should sense when the battery is full, and then should only allow a "maintenance" charge (trickle charge) to keep the battery topped off. Your converter is converting shore power (120 volt AC) to 12 volt DC to run your 12 volt appliances and lights. The converter SHOULD also have the ability to "sense" when the battery is full to prevent overcharging. Therefore both solar panel and converter will be able to contribute to keeping the battery up. I would check and make sure the panel has a diode, which acts as a safety valve to keep battery power from going back to the panel. A lot of good information is available from Solar Energy International (SEI) in Colorado, They also offer online courses.
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cowcharge
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Post by cowcharge on May 11, 2015 11:18:39 GMT -8
Wait... if the converter's not plugged in, how are you running anything off it?
I believe every modern solar charge controller and converter are designed to prevent current from going backwards. Many panels these days have blocking diodes as well. Your controller's manual, or even an online spec sheet, should tell you for sure. As should the solar panel's manual. And all three manuals should also have warnings if they don't play well together. If you don't have manuals, they're probably googlable. But I wouldn't worry too much, unless one or more of them are old technology, or malfunctioning.
Even if both solar and converter are running at once, if the solar controller's set to the proper voltages for wet batteries (assuming you're using wet batteries), which is 14.8v according to battery manufacturers like Trojan, then the converter is going to sense full charge and go to float mode first, because they're always set (too) low, usually around 14.4v for bulk charging, which doesn't last long before it drops to 13.6-ish for "normal" mode, and then to 13.2-ish for float mode. In fact, the converter may go to float as soon as the solar controller starts charging, since solar's pumping 14.8v into the battery right from the start. The converter will sense that, think the battery's charged, and go to float mode. The solar controller will keep charging until the batteries reach 14.8v, and if it's one of the better controllers like Morningstar, it will keep it there for quite a while, to stuff every last amp-hour it can into the battery. So the solar controller will be the last to go to float. Again, assuming it's set to a higher charge voltage than the converter. Whichever one is set lower will shut down first, and perhaps immediately upon the other's arrival.
If you're still concerned though, it would be a simple thing to install a selector switch to prevent them both being connected at the same time, and allow you to choose which source is charging at any one time.
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mobiltec
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Post by mobiltec on May 19, 2015 18:49:43 GMT -8
You aren't. You are then running off the battery.
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gary350
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Post by gary350 on Oct 28, 2015 6:23:45 GMT -8
This is what I have built.
Lead acid car batteries are self regulating when being charged. If the battery is low it will suck in lots of amps from the solar panels. As the battery becomes charged the battery sucks in less and less amps. When the battery becomes fully charged it will show almost zero charging amps on the meter. BE SURE your battery gets a full charge worse thing you can do to a battery is never give it a full charge and run it completely dead.
Make sure the charge voltage is NOT LESS than 15 volts. I bought 9 solar panels from Harbor Freight. They were all returned to the store because the charge devise that comes with the 3 panel kits were bad. Panels were discounted about 10% so that saved me a few dollars.
Reason you want 15 volts or higher to charge the battery is the batteries will charge faster. The closer the battery gets to full charge the slower the battery will charge. Without going into a lot of technical detail this is a quick easy EXAMPLE. Assume solar panels are producing 18 VDC at 1 amp, a dead battery will pull in 1 amp but a battery that is 1/2 charged will only pull in about 1/2 amp so it charges about 2 times slower than before. When the battery becomes 90% charges it will charge at 1/10 amp and take 10 times longer to charge. When the battery is 99% charged it only pulls 1/100 amp and will take probably another 24 hours to completely charge. Amp meter will show almost zero amps but the battery is still charging. The reason I say charge your battery with 15 volts of higher a difference of 1 volts can double the time it takes for the battery to get a FULL CHARGE.
I have 2 amp meters and 1 volt meter in this circuit that is only for ME it was a learning process to see what is going on. I learned during the day with the Inverter turned OFF with the switch on the front of the inverter it still uses power from the battery. My inverter uses enough power from the battery to run a full charge battery dead in 8 days with no solar charge and no lights or anything connected to the inverter. My inverter wastes power. YOU need to test your inverter to see it is uses power with the switch OFF. I bought a NEW inverter last week I have not tested it yet so I don't know it is wastes battery power. The reason the ON/OFF switch is in this circuit is to disconnect the inverter so it does not drain the battery with it is being charge or not being used.
You don't need these amp meters or volt meters I just did that for ME but it is very helpful to know what you battery and solar panels are doing.
I had a ysed 650 watt car battery we only use it for lights a few hours after dark and it will last 7 days before it goes dead with no solar panels. I bought a new 750 watt battery it lasted 9 days with lights only with no solar panels. Now I have a 1000 amp battery it will last 2 weeks with no solar panels.
If you want to run a refrigerator it takes several times more power to start the motor than it does to run the motor. The little refrigerator I use to have runs on 1.4 amps but needs 6 amps to start.
6 amps X 120 volts = 720 watts. I need a DC to AC inverter larger than 720 watts to run my refrigerator. My frig starts on 720 watts and runs on 168 watts. The refrigerator pulls about 18 amps using this big over kill inverter to run it with. There is no way to get the refrigerator started on a 250 watt inverter.
I use the smallest inverter I can to fun lights it wastes less power. I have a 100 watt and 150 watt and 250 watt inverter. Most if the time I use the 150 inverter we have 2 lights in the camper 60 watts each. If I change the bulbs to 40 watt I can use the 100 watt inverter.
Never connect batteries in parallel they run themselves dead charging each other. Never buy deep cycle batteries if you need more power buy 1000 amp 6 volt batteries and connect 2 batteries in series to get 12 volts DC. You can also buy industrial 2000, 5000, 10,000, 20,000. amp batteries.
My solar panels are 135 watts. Only way I can get a full charge on a 1000 amp battery is let it charge all week at home then when we go camping the battery is ready to use. I can do the same thing with a home battery charger then I don't need the solar panels. We go camping where there are trees I can not get a whole hours worth of full sun so the solar panels are useless to take camping in places we like to camp. On a nice summer day when days are long if you camp where there are no trees and can get full sun all day but the sky has clouds a 15 hour day may only give you 5 hours of full sun. If your camping in the desert solar panels are helpful but if not keep your batteries on the charger at home.
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