InstructionsTo use this spreadsheet enter your data in the shaded cells. All calculations are done automatically.This Excel workbook was developed by Gale Scholten (N8GS) using data collected for many different sources. I've tried to cover a lot of ground with this project but as with all such projects it is possible that an error may have crept into the data. Please confirm the results obtained before spending your hard earned money.Much of the example data included in this spreadsheet was obtained by testing the various items on my 30 ft. 5th wheel. I hope this will provide you with a solid starting point as you calculate your power needs. Note that electrical name plates list the MAX power used NOT the average power. A wire sizing section is included to make it easier to pick the proper size wire to use. Pay close attention to the Wasted Watts and voltage drop columns. Wasted watts is power that the solar panel is generating but never gets to the batteries because it is wasted in heating the wires. Bigger wire = less resistance = less heat = less wasted power..Panels wired in series provide higher working voltage (like batteries in series) which will allow the use of smaller wire BUT it will require the use of a MPPT style charge controller. You will need to decide for yourself which way best meets your present and future system requirements. If 3 - 12 volt panels with a Max power point voltage of 17 volts are to be installed in series then the input voltage to the charge controller will be 51 volts. Also check to insure that the open circuit voltage of the panels will not exceed the charge controllers maximum input voltage. Be sure to measure the space you have available for your PV panels. Will they fit and will there be a problem with nearby items casting shadows onto the panels? Could the TV antenna or A/C unit be a problem?

RV Load CalcLoad Calculation WorksheetStep 1 Calculate your AC loads. If there are no AC loads, skip to Step 2.Description of AC Loads Run by an inverterWattsXHrs/Day=Ah/DayMicrowave1950X0.1=15.5TV and antenna amplifier32X2=5.1Satellite receiver15X2=2.4Computer35X1=2.8Blow Dryer900X=0.0Electric Skillet1200X=0.0Toaster950X0.1=7.5Fan25X=0.0X=0.0X=0.0X=0.0X=0.0X=0.0X=0.0X=0.0AC Ah/Day including inverter losses39.1AhInverter efficency ---->>85%Inverter DC input voltage; This is the DC system voltage.--->12.6V

Step 2 Calculate your DC loads.List all DC loads in the spaces below. WattsXHrs/Day=Ah/DayFurnace114X1=9.0Water pump60X0.1=0.5Lights w/ 921 bulb (18w/bulb) (dining table)36X=0.0Bath area Lights all LED16X0.5=0.63 LED Light fixtures24X1=1.92 LED reading lights16X2=2.5Inverter idle current11X6=5.2Bath Vent fan12X0.3=0.3AM/FM radio6X=0.0Refrigerator (what is your duty cycle?)7X12=6.7Water Heater7X0.6=0.3Fan8X=0.0HP photo printer30X0.2=0.5HF radio 75.6X=0.0X=0.0X=0.0X=0.0X=0.0Phantom loads (control circuits, LP detector , refrig) 7X24=13.3Total amp hours per day used by DC loads.DC Ah/Day40.9AhTotal amp hours per day used by all loads.Total Ah/Day80.1Ah

Notes: Watts = Volts times Amps

Battery SizingBattery Bank Sizing1. Total amp hours per day needed to recharge the battery bank. (See solar array sizing page)80.12. Maximum number of days with no recharge.23. This is the Ah used + the extra amps needed to compensate for conversion losses.160

5. If you are using a lead-acid battery, select the multiplier below which corresponds to the battery's average ambient temperature:1If you do not intend to discharge below 50% this is your minimum battery size =====>320Ah @ 50% DOD

This is your suggested battery size in amp-hours if using 80% of the capacity ==>200Ah @ 80% DOD

Battery Capacity Multiplier TableTemperature adjusted charging voltage80F/26.7C114.6070F/21.2C1.0414.7760F/15.6C1.1114.9350F/10.0C1.1915.1040F/4.4C1.315.2630F/-1.1C1.415.4320F/-6.7C1.5915.60

Note: Charging voltages above 15.4 volts may damage some electronic equipment. Trojan specs their batteries as having a recharge efficency of 89% An MPPT controller will typically have a conversion efficency of 90% to 96%

Solar array sizingSolar Panel Array Sizing1. Total amp hours per day from the Load Calc Worksheet80.1Ah2. Multiply line 1 by 1.25 to compensate for loss from battery charge/discharge.100.1Ah3. Average sun hours per day in your area of interest.6hr/day4. This is the average Ah rate required for daily recharge.16.68A5. Watt hours needed to recharge the battery bank.1261WhWatts/hr. needed to replace 1 days useage assuming 85% efficency240Watts of tilted panels

For recovery from a cloudy period double the panel wattage.Double the panel size if used flat in the winter

Size the wire between the solar panels and the charge controller to provide a voltage drop of less than 2%. Use the copper wire table to help with this calculation and don't forget that the wire needed is twice the distance from the solar panels to the charge controller.If long wire runs are necessary it may be advisable to install the panels in series to raise the voltage. Then use a MPPT type charge controller.

Wire SizeWire Sizing chart59Input Voltage8Amps472watts50Length of wire in feet (both + and - conductors)

Ohm/1000'Wire Dia. (inches)Wire Size AWGWire ResistanceVoltage dropPercent Voltage DropWasted WattsOutput Voltage41.0200.0159262.0510016.40838.5%131.342.5925.6700.0201241.2835010.26821.1%82.148.7316.2000.0253220.810006.48012.3%51.852.5210.1280.0320200.506404.0517.4%32.454.956.3860.0403180.319302.5544.5%20.456.454.0180.0508160.200901.6072.8%12.957.392.5240.0641140.126201.0101.7%8.157.991.5890.0808120.079450.6361.1%5.158.360.9990.1019100.049950.4000.7%3.258.600.6280.128580.031400.2510.4%2.058.750.3950.162060.019750.1580.3%1.358.840.2480.204340.012400.0990.2%0.858.900.1970.229430.009850.0790.1%0.658.920.1560.257620.007800.0620.1%0.558.940.1240.289310.006200.0500.1%0.458.950.0980.324900.004900.0390.1%0.358.960.0780.3648000.003900.0310.1%0.258.970.0620.40960000.003090.0250.0%0.258.980.0490.460000000.002450.0200.0%0.258.98

Peukert FormulaPeukert Formula - Battery Run Time to Depletion

Peukert's Exponent1.192 Batt Bank Capacity Ah600Amp Hour Time Rating20 Total AmpDepth of DischargeAh used Hours15%90AhDischarge Rate in AmpsTime in hoursAvailable20%120Ah24.026.09626.350%300Ah36.016.09579.480%480Ah48.011.42548.260.0 8.75525.2120.0 3.83459.8180.0 2.36425.3 240.0 1.68402.5 300.0 1.29385.6Battery Life360.01.03372.3Enter a specific 420.00.86361.5discharge rate4.0hr20%DOD480.00.73352.33010.0hr50%DOD540.00.64344.516.0hr80%DOD600.00.56337.6 20.0hr100%DOD

NotesTrojan specs their battery recharge efficency at 89%.

Battery Capacity Multiplier TableAdjusted charging voltage80F/26.7C114.8070F/21.2C1.0414.9760F/15.6C1.1115.1450F/10.0C1.1915.3040F/4.4C1.315.4730F/-1.1C1.415.6420F/-6.7C1.5915.81Note: charging voltages above 15 volts may damage some electronic equipment.

Cost estimateSystem upgrade cost estimator (2011 prices)QtyItemEstimated Unit priceExtended costKyocera KD135GX$390.00$0.002Kyocera KD235$455.00$910.0050#12 2 conductor cord$1.20$60.0015#10 wire$0.80$12.00#8 wire$1.00$0.0045#6 wire$1.25$56.25#4 wire$1.90$0.004#2 wire$2.25$9.00#1 wire$0.001/0 welding cable$0.00102/0 welding cable$4.00$40.00Junction box on roof$15.00$0.001Outback FM60 charge controller$529.00$529.001RTS Remote temp sensor$29.00$29.00FM60 remote display$257.00$0.00sets of mounting hardware$42.00$0.0015 amp 125 volt Fuse block @ PV panels$15.00$0.0015 amp fuse$3.00$0.001300 amp Battery fuse block /w fuse$90.00$90.001Xantrex Linklite battery monitor w/ shunt$248.00$248.006#6 x 5/16 copper lugs0.85$5.1042/0 x 3/8" copper lugs$1.25$5.00102/0 x 5/6" copper lugs$1.25$12.502/0 split bolts$6.00$0.001IOTA 90amp w/IQ4$345.00$345.0022LED panels to replace 921 bulbs$18.00$396.004Trojan T1275 batteries 12V (150Ah each)$199.94$799.762MC4 extension cable - 6 feet$20.00$40.00350 amp Buss CB$29.00$87.00132 gal Blue Boy$279.00$279.001Macerator pump$259.00$259.00$0.00

Total$4,211.61

Resistor calc

Parallel resistor Calc.Wheatstone Bridge

R1350R1500R1600Supply Voltage12.6R210000R21000R21000R110000R310000R32700R210000R410000R310000Rx10010Result =338.1642512077R result =322.5806451613R result =318.772136954Voltage inbalance=0.0031

Temp compTemperature compensation chart by Mark Siminoff - siminoff@gmail.comWhat is the float voltage setting ?13.40VWhat is absorption voltage setting #?14.80VWhat's the temp' compensation coefficient?0.028V/C

CF13.4014.8003214.1015.5013414.0715.4723614.0415.4433714.0215.4243913.9915.3954113.9615.3664313.9315.3374513.9015.3084613.8815.2894813.8515.25105013.8215.22115213.7915.19125413.7615.16135513.7415.14145713.7115.11155913.6815.08166113.6515.05176313.6215.02186413.6015.00196613.5714.97206813.5414.94217013.5114.91227213.4814.88237313.4614.86247513.4314.83257713.4014.80267913.3714.77278113.3414.74288213.3214.72298413.2914.69308613.2614.66318813.2314.63329013.2014.60339113.1814.58349313.1514.55359513.1214.52369713.0914.49379913.0614.463810013.0414.443910213.0114.414010412.9814.384110612.9514.354210812.9214.324310912.9014.304411112.8714.274511312.8414.24