36 volt solar panel

[jimindenver]

The Eco-W is good for up to 300w as long as the Voc is under the 50v limit.

 

[MikeRuth]

Watts... a watt is a watt is a watt.

Wattage is a power level and can be generated at different voltages and currents yet all equal the WATT.
Using Ohms law of P=I*E

So at 12 volts dead on yes 200 watts would be 200 / 12 = 16.66 Amps. Yet if the panel is putting out say close to it's rated voltage into the CC you could have...
18 volts, therefor 200 watts from 18 volts would be a current of......200/18=11.11 Amps. See where I'm going with this? that's a 5 amp difference and still 200 Watts.

Best case is to go with what the controller is rated for. In the case of the ECO since it is rated for 20amps then you would want to have panels that would supply no more than 20 amps to the CC.

Now some panels are better than others but you would be safe to add up the Short circuit current rating(Isc) in a series set and not exceed that.
Say three panels listed at 5.75 Amps and you have 17.25 amps max going into the CC.

If your running them in parallel then the amp rating would still be 5.75 but you would add up the voltage so as not to exceed the CC max Voltage.
3 panels at 18.9Volts would make 56.7 volts.

Lest we not forget there are losses in all of this and these numbers are for no loss. with losses were going to be under the max a bit.

 

[Oneleggedcowboy]

It's 275 watts max but I am hooking it to a 36 volt and 245 watt panel. The little magic man inside the box turns the extra volts into amps. Don't know how but I think it might involve Preparation H. LOL ROFLMAO

 

[BigT]

Every time I think I know what CC to buy, somebody throws a wrench into the works.   :s  What happens if I run more than 275 Watts into it?  Will it hurt the CC or simply be wasted Watts?  

Can you tell me if it will work with this panel?  http://www.mlsolar.com/lg-monox-295...mm-frame-solar-module-module-efficiency-18-0/

 

[Oneleggedcowboy]

I have no clue but the pros will weigh in here directly.

 

[blars]

A properly designed charge controller will not have problems with too many watts of panels, and will just put out it's maximum amps. However, too high a voltage can cause problems, and panels can put out over their rated VOC voltage under cold, high altitude, no load conditions.

 

[Oneleggedcowboy]

Ok I can't use the load to charge my house battery.

I will use switches. I like the fact that I will be able to see the charge in the house battery on the Eco Worthy. By the way tracking says it is the US now and in the hands of the USPS!!! Yee haw!

So what reading on the Eco Worthy would tell me the house battery is fully charged and I can switch it back to the solar battery bank? I know I can't go by volts so it must be Amps that will tell me?

 

[Oneleggedcowboy]

Yowser got my Eco Worthy controller and 10 awg in line fuses in the mail yesterday. Gonna hook it up in front of the barn laid out on the ground to see how the system works. I have a fusing question... I intend to put a 20 amp in line 10 awg fuse between the panel and the controller. Fuses provide resistance so I wonder if I need a fuse in my 8 awg wire going to the battery from the controller? I read to put it as close to the battery as possible but it will be a 8 awg wire going into a 10 awg wire fuse.

 

[Optimistic Paranoid]

Yowser got my Eco Worthy controller and 10 awg in line fuses in the mail yesterday. Gonna hook it up in front of the barn laid out on the ground to see how the system works. I have a fusing question...  I intend to put a 20 amp in line 10 awg fuse between the panel and the controller. Fuses provide resistance so I wonder if I need a fuse in my 8 awg wire going to the battery from the controller? I read to put it as close to the battery as possible but it will be a 8 awg wire going into a 10 awg wire fuse.

Every set of instructions I've ever seen say that you need a either a fuse or a circuit breaker in the hot wire between the controller and the battery.

Unfortunately, splicing a 10 gauge fuse holder into an 8 gauge wire is exactly the same as if you cut out a one foot piece out of a long 2" pipe and spliced a piece of 1" pipe into the gap.

Once you go to wires bigger than 10 gauge, you go to ANL fuses and fuse holders like THIS:  http://www.amazon.com/Scoshe-EWFH-S...90176&sr=8-1-spell&keywords=anl+fuase+holders

Regards
John

 

[highdesertranger]

they make maxi fuse holders with 8 gauge wire. http://www.amazon.com/Pico-0969PT-I...sbs_263_1?ie=UTF8&refRID=09KH28AS05TTSFQSEJSB . the problem is the smallest maxi fuse is 20amp. is that to much? highdesertranger

 

[Oneleggedcowboy]

Highvdesertranger you got the right idea. I just ordered some 8 awg in line fuses with 20 amp guses. That's the size I need for between the panel and controller and between the controller and battery. I already have a 150 wstt massive thing that goes between the battery and inverter. I know the inline fuses like I am going to use are not as good as breakers and others but it's what my money can do right now. I am really looking forward to getting this working and trying my trip west with my horse! I am a amputee so can't hike much but maybe with Chips I can see what the hikers see!!!!

 

[Oneleggedcowboy]

John thanks for your excellant advice and analogy. You were very correct and I have now adjusted the build to compensate to the best of my financial and actual ability! Thanks pardner!!#

 

[highdesertranger]

good deal cowboy. highdesertranger

 

[Oneleggedcowboy]

Hey I know yall think I didn't finish and fell off the world out of sight but.....

I HOOKED IT ALL UP TODAY AND IT WORKS!!!

Yes it's was partly cloudy, hazy here in coastal Carolina and I got 34.2 volts and 2.98 amps bulk charge for a little while and then the batteries were fully charged. I put them on a battery charger the other day to top them off. So are those good numbers?

I have two trojan golf cart batteries to run my 1500 inverter and a 12 volt marine battery to run the camper. Which only runs the 12 volt lights and overhead vent fan. The battery systems are separated with 20 watt in line fuses. Right now the 12 volt marine has no fuse. I will switch them 2moro and see see how that works!

245 watt panel mounted flat, wonder what a good amp and watt number is?

Can't wait to see what it does in the sun light!

 

[jimindenver]

That's great cowboy.

The max amps I see out of a 245w mono is 17a. !8.5a is the best I have seen out of a 250w poly. Those numbers are with the panel pointed directly at the sun so flat will be lower unless it's mid summer and high noon. Winter numbers will be lower than summer numbers because the sun is lower on a flat panel.

 

[Oneleggedcowboy]

Hey thanks! Wow that's a big difference. I don't know which I have.

 

[Oneleggedcowboy]

Hey the solar rig is working great. On my way to Qusrtzsite. Stuck in New Mexico in a dust storm right now. Got lights galore, led of course, water pump is good to go. Making drip coffe in the am and microwaving oatmeal!!   Have seen 13 amps as best so far but always seems partly cloudyso fsr. Thanks for all the advice and help!

 

[Canine]

Congratulations cowboy.Looks like you have it cyfered out.