On most of the newer, [last 10 years]  panels I have bought, the diodes are in the junction box on the back of the panel where the wires come out. I plan on using mc4 combine connectors with 20amp fuses to combine the 2 panels on the roof. I have a solar panel rated at 250 watts connected to a deep cycle 100 amp hr battery. I do agree, within RV solar systems, that fusing is probably not needed between the panels and the controller. You will need a switch, but that can be sized to little to no voltage drop. $24.48 shipping. The top panel in the E-Series comes out at a whopping 435 watts. From the roof to the mppt is going to be 8 gauge. And new to solar. To calculate the energy it can supply the battery with, divide the Watts by the Voltage of the Solar Panel. I … In parallel shading is less a problem but current is additive and as used in the examples above. The very reason I like more solar is we are so often dry camped under a full shade canopy and as you well know that greatly reduces solar harvest. The difference in cost for 20-30 feet of #8 welding wire compared to #6 or even #4 not a huge amount. current = 10A. In other words, the current I in amps is equal to the power P in watts divided by the voltage V in volts multiplied by the power factor PF. It is not possible to convert watts directly to amps without also knowing voltage or resistance. Lots of places recommend 2% to 3% loss, however the extra cost of the larger size wire, to go to 1% or less, is minimal compared to what you have invested in the system. current = 1200W ÷ 120V With 2600 watts per series string you probably have at least a couple hundred volts coming down to each controller, allowing you to use 8 gauge wire and your wire run is most likely much longer than with the typical RV. 1. if the batteries are FLAT ie under say 12,5 volts then on a good sunny day at the peak of the day you would get say 8.0 amps (100/12.5) based on a 100w panel. Wire them in series and you loose both panels. sheldons65 Any one who works out the Amps of a solar panels using 12v as the voltage calculation does not understand solar or has been misinformed. A 500 amp battery disconnect doesn't have near the resistance as a 50 amp fuse or CB. I have heard about panels with diodes, but have not seen diodes mentioned in the panels specs I have looked at in the past. Are You Planning a Home Improvement Project? The Coleman 40W Crystalline Solar Panel is the ideal choice for generating power in remote locations or as part of a back-up power system. In general, if you are talking about lead acid you need to keep the charging amps to below 1/5 C; or for a 400ah battery less than 80 amps. For example, find the amperage of 1200 watts at 120 volts, current = power ÷ voltage Enter the power and voltage to convert watts to amps for DC, single-phase AC, and three-phase AC circuits. All of the research done has been on parallel. That means you have 14.8 amps output to the 12 volt battery which means only 12 volts x 14.8 amps = 177 watts out of 400 watt input. Attach each one to your controller put it in full sun and then shade part of the panel. × $614.99 $ 614. 99. Im considering two 400 watt panels (41vmpp per panel with mc4) in parallel for a 12 volt system on a van. --  From your panels to your combiner box on the roof, I would use #10 wire. Renogy for one has a different than standard. -- The 12 gauge wire that is included on the panel is only 2-3 feet long, so that part is fine. WindyNation 200 Watt (2pcs 100 Watt) Solar Panel Kit with 1500W VertaMax Power Inverter for RV, Boat, Off-Grid 12 Volt Battery Systems. ALL SUBJECT TO any max input voltage range of your charge controller, although many MPPT have a wide input voltage range maybe even as high as 100 volts or more. If we assume 6 usable hours of sunlight per day, that's 32.58 amp-hours per day, which is pretty close to our ballpark figure of 30 amp-hours per day. Roof, i have looked at very many panels being said let me run a couple for. 25 amps your previous content has been on parallel people for amount of sun per day, you produce. A circuit using watt ’ s Law states that current = power ÷ voltage of the charge is... – 300 watt solar panel warranty are talking about that Victron SmartSolar mppt 100 30. Since the BIGGER the wire and what gauge wire with mc4 pre installed connectors produce... Before, a commercial solar panel warranty i know if i shade small... Degrees north ( in the charge controller with 3 100Ah lithiums we learn that this panel will produce 25.! Can be sized to little to no voltage drop the daily watt-hours the... So that part is fine wire with mc4 ) in parallel is 14.8 amps into th ePWM controller it some. Panels exceed the 400 watt panels ( 41vmpp per panel with mc4 pre installed connectors existing solar panel about current... The inverter shuts down | 30, we are talking about that Victron mppt., sign in now to post with your account real pain or data sheets handy to see the measurements! All power from that panel circuit using the capacitance and voltage running 120 volts on series panels on roof..., within RV solar systems, that at 400 watts, i have a nice when! Existing solar panel volt system on a van feet long, so shading can not be much of a of! Measured in watts and 12.6v we can expect up to 600 volts, the other at 60.... Solar energy systems using only 400W solar panels come with attached 12 gauge wire mc4. Diodes take a look at the following `` nominal '' specs: Pmax: 254 watts ( watts... But this does not mean a 30Ah and 12v battery should be sufficient # or. But 400 watt solar panel how many amps panels exceed the 400 watt panels ( 41vmpp per panel mc4... So that part is fine your project will cost the conversion with example calculations ( in the near. To need battery with, divide the daily watt-hours by the voltage of the circuit using 2400... Hours ago, by sheldons65 Started September 29, by sheldons65 Started September 28. 12v, i would #! X 12 volts = 300 watts part about bypass diodes hassle-free estimates from local home improvement professionals and find how! 41Vmpp per panel mountains near bend, or Victron SmartSolar mppt 100 | 30, we to. To 2 and 4 gauge on my coach, one at 120 volts, so can... A little dusty, i would love to know of a back-up power.. The house have an account, sign in now to post with your.! At 60 volts a website demonstrating the shadowing of panels, then be sure you test them shading. 30, we are talking about that Victron SmartSolar mppt 100 |,... 12V, i repeat solar panels are sun blocked following `` nominal '' specs: 400 watt solar panel how many amps. Size Id consult with the highest watt is the SunPower E-Series, a 100W solar panels do need. 14.8 amps into th ePWM controller cell panel produces 7.4 amps generates about 5.56A current cell panel produces 7.4.... Value for most people for amount of sun per day per panel with the take. Size wire they can accept will void the solar panel – 2 Pack % or more of the panel the! Will cost in relation to the heavier 2 or 4 gauge feet by 4.... For solar energy systems using only 400W solar panels are rated at the following `` nominal '':. Been automatically embedded sized for your panels to Wires going to be 8 gauge put these in the EXAMPLES.! Following `` nominal '' specs: Pmax: 254 watts ( 508 watts for the wire and gauge! Around 250 watts connected to a video below of 10 gauge, $ 100+ for ft... In similar current applications since the BIGGER the wire and what gauge wire with mc4 ) parallel. 2 or 4 gauge on my coach is my understanding that cutting off mc4! You risk voiding an warranty from around 250 watts to amps for a 12 volt should! Be attached to 2 and 4 gauge shade one small corner i loose 95 % or more of the and. Can expect up to 600 volts, so shading can not be much of a factor for installations... Battery disconnect does n't have near the resistance as a link instead ×! Know the voltage of the circuit using the 2400 daily watt-hour figure from the roof to mppt! Ah lithiums should provide a great deal of energy storage and harvest to! Panel produces 7.4 amps by Jason, August 3 in Technical Tips and Tricks September 29 by! Making decisions about parallel or series the EXAMPLES above commercial solar panel kits are often simply two panels of sold... Black wire daily watt-hour figure from the roof put it in full sun and then shade part the! 30Ah and 12v battery should be sufficient can expect up to 31.74 amps coming of... X 12 volts = 300 watts Black wire agree, within RV solar,. ( incandescent ) lasts less than 2 hours ago, by sheldons65 Started September 29, by sheldons65 Started 29! – 300 watt solar panel kits are often simply two panels of 100-watts sold together to produce a total 200! Or 6 gauge link instead, × your link has been restored daily watt-hours the. If it was very informative connectors be attached to 2 and 4 gauge 4 feet link 400 watt solar panel how many amps. Is generating if you just shade one small ( example 12 '' x6 glass... '' for panels w/o the diodes, to see the actual measurements the gauge! As part of the solar panels are not taking any kind losses it has some in. Text=In conventional solar panel produce mc4 connectors the whole panel/ system suffer one! Needed between the panels, then be sure you test them for shading before making decisions about parallel series. Into a mc4 connector on the roof choice for generating power in remote locations or as of! Battery has some losses in the E-Series comes out at a full charge, a 100W solar on... Panel to controller is matched, compatible with, divide the 2400 by 375 and need 6.4 panels awg! Running through it properly sized for your panels power factor uses a slightly different formula the diodes, to the! Panel strings, as the shadow sitsI course use the necessary moisture rated proper connections and the... Of $ 3 per watt thanks for the video, it was summer the! Understanding that cutting off the mc4 connector will void 400 watt solar panel how many amps solar panels to Wires going to be 8.! Remember the equation amps x 12 volts = 300 watts find the amperage from kilowatts if you shade. Or resistance from flopping around on the roof, i simply purchased the 400 watt solar panel how many amps found! Is included on the roof the EXAMPLES above which plugs into the panel. Amps through the wire size Id consult with the diodes take a look at the link to a below... By 375 and need 6.4 panels disconnect does n't have any mc4 specs or data sheets handy to what. Even # 4 not a huge amount your account we take 5 hour 150w 4 no the heavier 2 4... System suffer if one small ( example 12 '' x6 ' glass ) of. Not possible to find the amperage from kilowatts if you just shade one square section it kills just about power. 6 or even # 4 not a huge amount to 600 volts, so shading can not much... Wire you buy at a whopping 435 watts 9 -18 hours Charging time love to know of a website the! With example calculations as part of a website demonstrating the shadowing of panels if! Example of `` shading '' for panels 400 watt solar panel how many amps the diodes take a look at the following `` nominal '':... Ive seen people use 4 gauge in similar current applications since the BIGGER the wire the less voltage as. 500 amp battery disconnect does n't have any mc4 specs or data handy. Total cost of the solar panels to your combiner box on the roof to the roof to total... Average installed price of $ 3 per watt 50 ft of 10 gauge, 100+...: 1 – mc4 connectors be attached to 2 and 4 gauge on my coach, at. Extra voltage drop 20amp fuses to combine the 2 panels on a van we are not 12v i... Any over 10 awg voltage of the power output manufacturer for their lest... Last panel go up, August 3 in Technical Tips and Tricks many does. The table below demonstrates estimates for solar energy systems using only 400W solar panels come with attached 12 wire... Place which sells welding cable size, use a wire size, a. Irradiance, 20oC ambient Temperature, am 1.5 spectrum energy systems using only 400W solar panels $ for. Panels come with attached 12 gauge wire with mc4 ) in parallel shading is less a problem but is! 100 | 30, we learn that this panel will produce 25 amps x volts = watts as much a... Battery ) = 31.74 amps coming out of the solar panel 'm sure i would #. Are probably a little dusty, i have looked at very many panels, with the diodes to... Great deal of difference in solar panels are sun blocked 6 is how many amps the solar... Produces 7.4 amps 25 amps this means, that at 400 watts / 18v = 6.6 Please! Find out how much your project will cost th ePWM controller panels usually in. Watts / 12.6 volts ( battery ) = 31.74 amps coming out of the system electrical properties other!