# 500 watts PV will produce how many amps?

pyana1
Solar Expert Posts:

**39**✭✭
Good morning !

i'd love to purchase two of these panels --> http://sunelec.com/sonali-pv-module-250w-polycrystalline-etl-to-ul1703.html?search=250 <-- totaling 500 watts, but i dont know how many amps it'll produce. i have 4, 6 volt trojan batteries .

if possible i'd like to know that amps for a 12 and 24 setup please.

i'd love to purchase two of these panels --> http://sunelec.com/sonali-pv-module-250w-polycrystalline-etl-to-ul1703.html?search=250 <-- totaling 500 watts, but i dont know how many amps it'll produce. i have 4, 6 volt trojan batteries .

if possible i'd like to know that amps for a 12 and 24 setup please.

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## Comments

4,994✭✭✭✭These are just a small part of a solar energy system, shipping alone might cost as much as a single panel! There are 2 basic types of Charge controllers which you will need to insure proper charging of your batteries. These are designed for use with MPPT types of charge controllers which will convert the wattage into usable energy for charging the batteries. A midnite 'Kid' will cost you about $300, with it you can expect (500watts x .75 panel in normal temps) ÷ 24volts = @15.5 amps at 24 volts per hour of good sunlight) or 2x that at 12 volts. Most areas in the US receive 3.5-4 hours of good sun per day on average, less in winter, more in summer.

766✭✭✭✭If you have to ask that question, I really hope you are not putting this together your self.

Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

39✭✭lol, oil pan 4, hopefully i'll find some help, by HIS grace....

thank you very much, Photowhit ! can you please tell me where'd you get .75 you multiplied 500 from?

and which morningstar tristar mppt charge controller would you recommend (TS-MPPT-30 the 30 amp version) or (TS-MPPT-45 or the 45 amp version)

4,994✭✭✭✭Normal Operating Cell Temperature - NOCT value. Solar panels are tested by 'flashing' them with a uniform amount of light. In NOCT the wattage will be less, Normally about 75-77% though I think I've seen it dropping a bit over time. Many Panel manufacturers now publish this value on their spec sheet.

I like Morningstar as a company, but have no experience with the charge controllers you've asked about.

3,009✭✭✭✭With a good MPPT controller, (such as the Morningstar models you mentioned in a later post), depending on the temperatures your panels will be exposed to (the lower the temperature, the higher the power output will be) you could expect a max of around 30 amps to charge a 12 volt battery bank, or 15 amps to charge a 24 volt bank. ROUGHLY speaking. And in case you're not sure - - 30 amps at 12 volts is just as good as 15 amps at 24 volts. POWER in Watts, is amps multiplied by voltage. I would strongly suggest going with 24 volts as there is less power loss in the wiring AND more important - - - you have four 6 volt batteries, which will live a better life wired in a single string of 4, rather than two parallel strings of two. It's not always easy to ensure equal loading and equal charging with parallel strings of batteries, and this is important for good battery life. Also, if you go with a 24 volt system, the TS-MPPT-30 will easily handle the job, but if you go with 12 volts, you could at times, push this controller to it's max. Don't paint yourself into the 12 volt corner like I did.

By the way, I've had 5 Morningstar products over the years, both inverters and controllers, and except for one controller I destroyed because of over-voltage from the hydro turbine, they all have performed perfectly well. Good, solid designs that require no cooling fans, are all but silent and unlike some controllers I've experience with, RFI is not a problem.

251✭✭✭My PV's are rated at 430 watts. I have seen (briefly!) charge current of as much as 16.5 amps at nominal 24 volts.

More realistic values are 12-13 amps max after the panels warm up.

So your 500 watt panels should give you somewhere around 15 amps at 24 volts.

59✭✭I was running 490w in mono panels tracking last summer. On a clear cold morning it would hit 34.2a @ 12v.