I have a 2013 Springdale 232 that came from the factory with a 10 watt solar panel that is wired into the converter. Obviously this is too small and I am in the process of designing my new 260 watt system. My question is do I need to disconnect the small panel in order for the new system to work properly. I am worried about some type of false reading because of the solar panel connected to the converter.
Should I Remove Small Solar Panel?
- Thread starter FB Coach
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Great Horned Owl
Well-known member
I assume that you will be connecting the new panel to the converter via a solar panel controller. Having an additional (smaller) panel in parallel on the input to the controller will just add a little extra capacity.
Joel
Joel
If it were me, I'd connect that 10W panel directly to the chassis battery and attach the 260W array directly to the coach batteries (separate controllers of course). I assume that you realize that you need at least 8G wire for that size solar array all the way to the controller and from the controller to the batteries (not the converter).
What size battery bank do you have? It's best to match the solar array to the batteries........ 1ah of battery capacity for every watt of solar panels. A 260W array should make a nice set-up that you can permanently mount and forget. On sunny days, it should afford you the ability to use the microwave once in awhile, some TV and the electric coffee pot. If you use LED lights, you can forget about running around shutting off lights.
To answer your question more directly, it will not hurt anything to wire the 10W panel in with the larger panel. The bigger question is... Why bother?
What size battery bank do you have? It's best to match the solar array to the batteries........ 1ah of battery capacity for every watt of solar panels. A 260W array should make a nice set-up that you can permanently mount and forget. On sunny days, it should afford you the ability to use the microwave once in awhile, some TV and the electric coffee pot. If you use LED lights, you can forget about running around shutting off lights.
To answer your question more directly, it will not hurt anything to wire the 10W panel in with the larger panel. The bigger question is... Why bother?
Wavery- Question for you, the new panels come with the MC4 wires already attached to them. I was going to use about 10' of that cable before connecting to a combiner box and then run #8 wire. Is this a issue. I don't know how you can have #8 wire coming directly from the panel junction box. I know the problem is drop in voltage across the smaller wire, but will that short of run have that much effect?
I assume that you are doing a permanent installation as I did. I just cut off the MC4 connectors, soldered the wires together and used heat shrink.FB Coach said:
If you want to use the MC4 connectors, you can get these "Y"s to connect the panels together, then run your new wires down to the controller.
http://www.amazon.com/Solar-Panel-Mc4-Parallel-Connection/dp/B008JHYVP6/ref=sr_1_3?ie=UTF8&qid=1368634729&sr=8-3&keywords=MC4+Y
Do a search for MC4 connectors on Amazon and you will find everything that you need.
Voltage drop when pushing amps through wire from the solar panel to the battery is more critical than when pulling amps through wire from the battery to a motor or light. #8 wire is recommended for even short runs for arrays over 200W.
What controller are you using?
Yes a permanently mounted system. The panels say that if I cut the MC4 connectors off it will void any possible warranty. I was going to use the MC4 cables for the entire run, but they are only #10 and I'm worried it might be too small. My latest plan is for about a 6' run of #10 MC4 cable to a combiner box and then #8 wire for about 30' to the controller.
Controller to Batts is only 4' and will be #8 Wire.
What do you think of this plan?
The controller is a Morningstar SunSaver 20Amp 12 Volt.
Also running it throught two 15 amp DC Brakers.
Controller to Batts is only 4' and will be #8 Wire.
What do you think of this plan?
The controller is a Morningstar SunSaver 20Amp 12 Volt.
Also running it throught two 15 amp DC Brakers.
It sounds good. I'm just wondering why you wouldn't use the "Y" cables instead of a splitter box. The splitter box just seems like a source of trouble (more possibility for loose connectors, corrosion etc) over the long haul. The "Y" cables would also give you the option of cutting off 1 leg of the "Y" and soldering your 8G wire to that (preserving your solar panel warranty).FB Coach said:
Not sure of the reason for DC breakers either...... A simple 30A inline fuse at the battery should be sufficient.
http://www.amazon.com/In-line-ACT-Water-resistant-Fuse-Holder/dp/B0002KR88A/ref=sr_1_1?ie=UTF8&qid=1368638846&sr=8-1&keywords=atc+fuse+holder
The more connections and gizmos in the system, the more chances of problems. Proven principle = "KISS"
BTW, if you are using 2- 230W panels, check the voltage output on the panels. If they are 30+V (which they probably are), be sure to wire the panels in parallel and use the 24V to 12V settings on the controller. If they are 18V panels, wire them in series.
You only need a 15A controller with that Morningstar. You can go to a max of 400W @ 24V.
I didn't know about the Y cables, I will use those and forget about the combiner box. Thanks for that tip.
The circuit breakers are so I can turn off the panels or batts if needed for some reason, and for protection. I tend to over due things.
My panels are 140W and 120W due to space restrictions. I'm still confused on parallel vrs series. Some articles I read say parallel and some say series.
The circuit breakers are so I can turn off the panels or batts if needed for some reason, and for protection. I tend to over due things.
My panels are 140W and 120W due to space restrictions. I'm still confused on parallel vrs series. Some articles I read say parallel and some say series.
Check the output voltage on the panels (it's on a label on the back of the panel). For some reason, I had it stuck in my head that you might be using 2x 230W panels, even though I knew better :FB Coach said:
...... Just too much going on here.....Chances are, those are 18V panels. If it were me..... I'd run them in series. The higher voltage cuts down on the amperage which takes less resistance. Sorry about my confusion on the size of your panels
...... if you run them in series, you can use 10G wire........ ;DIf you use the inline fuse, all you have to do is pull the fuse in the unlikely event that you want to stop the input into the batteries. Remember, the solar controller is a very sophisticated voltage regulator. When he batteries are fully charged, it turns itself off. The main reason for the fuse is to protect against a short somewhere in the wiring to the panels.
To properly charge batteries you need amps. Low amp chargers will only surface charge them and eventually ruin the battery.
Lead will collect at the bottom of the battery, and turn the fluid black. They will read 12v, but will not deliver amps.
To get amps out of a bettery you have to put amps into it, so that the plates will be rebuilt, i.e. lift the lead off the floor and put it back onto the plates.
A battery below 10 or 11 v, will draw 50 plus amps from a charger if the charger will deliver it.
A 120 watt solar cell at 12v is delivering ~10 amps and that assumes full sun light. At 18 v, 120 / 18 = 6.67 amps.
The minimum amps needed to properly charge a battery is 15.
Thus if you hook solar panels in series, it would appear tome that your not going to be able to properly charge the battery. ???
Lead will collect at the bottom of the battery, and turn the fluid black. They will read 12v, but will not deliver amps.
To get amps out of a bettery you have to put amps into it, so that the plates will be rebuilt, i.e. lift the lead off the floor and put it back onto the plates.
A battery below 10 or 11 v, will draw 50 plus amps from a charger if the charger will deliver it.
A 120 watt solar cell at 12v is delivering ~10 amps and that assumes full sun light. At 18 v, 120 / 18 = 6.67 amps.
The minimum amps needed to properly charge a battery is 15.
Thus if you hook solar panels in series, it would appear tome that your not going to be able to properly charge the battery. ???
His controller is designed to handle 36VRobertR said:
:http://www.morningstarcorp.com/en/sunsavermppt
Wavery said:
Thanks I changed my post after thinking about it.
I was going through batteries like they were water, until I figured this out.
I am unclear as to how less amps is going to get the job done? Thanks
The controller switches the voltage back to the desired volts/amps that is best suited for the state of charge of the battery.RobertR said:
Remember the formula is always V x A = W. The controller just changes the higher voltage to lower voltage which increases the amps..... the watts never change. The problem comes in if there is resistance in the wire. That resistance generates heat which consumes watts.
I see so if you have 10 amps going into the charger at 36v, you have 20 leaving it at 18v. That would be better.
I am going to have to check my controller and see if it handles 36v. Simple to switch the wires around on the roof.
Learn something new every day. Thanks.
I am going to have to check my controller and see if it handles 36v. Simple to switch the wires around on the roof.
Learn something new every day. Thanks.
I don't know what kind of controller that you have but mine has a place for 12V and another place for 24V.... 12V charges @ 18V from the panels. 24V charges at 36V from he panels.RobertR said:
The MPPT controller do more than the simple V/A conversion...... they have some kind of inverter action going on that will output about 10% higher amperage than a PWM controller. However, for the price difference between the 2 different type controllers, one can purchase another 100W of solar panel...... I just couldn't justify paying $225 for the SunSaver MPPT controller when I could buy a PWM controller for $20.
