How Long To Charge 100Ah Battery With 200 watt Solar Panel?

Can a 200w solar panel charge a 100Ah battery? The short answer is YES, you can charge a 100ah battery with a 200-watt solar panel.

In Short, a 200 watt solar panel will take 4.2 peak sun hours to fully charge a 12v 100ah lead-acid battery from 50% depth of discharge or 7.5 peak sun hours to fully charge a 12v 100ah lithium (LiFePO4) battery from 100% depth of discharge using an MPPT charge controller

Need an Easy solution? use the calculator below to find out.

Or keep reading if you want to know how different voltage and types of battery will affect the charge time and what are solar peak sun hours.

Battery Charge Time Calculator

Solar Panel Size
Watts
Battery Capacity (Ah)
Ah
Battery Volts (V)
Volts
Battery Type
Battery Depth of Discharge (DoD)
%
Charge Controller Type

Note! Use this solar panel size calculator if you want to find out what size solar panel you need to charge your battery in desired peak sun hours.

Disclaimer!

1- The estimated charge time is not the total number of sunlight hours but the number of peak sun hours ( keep reading I’ll explain in a bit )

Calculator Assumptions

  1. Lead-acid, AGM, & Gel Battery charge efficiency: 85% 
  2. Lithium (LiFePO4) charge efficiency: 98%
  3. MPPT Charge Controller: 98% efficient
  4. PWM Charge Controller: 80% efficient
  5. Solar Panel Efficiency: 80% (which is the most common figure)

How to use the calculator

Enter the values into the calculator ( mentioned above) as described.

  1. Enter the total solar panel array size: in this case, it’ll be 200 ( for 200 watt solar panel )
  2. Enter Batter capacity in amp-hours: for this example, it’ll be 100
  3. Enter the battery voltage: is this a 12, 24, or 48v battery? ” Enter 12 for 12v battery ”
  4. Select Battery Type: Select “Lead-acid” if you’re using a flooded or sealed (AGM or gel) lead acid battery. Select “Lithium (LiFePO4)” if you’re using a lithium iron phosphate battery.
  5. Enter battery depth of discharge (DoD): DoD is the percentage of the battery that has been discharged relative to the total battery capacity. for half discharged battery you’d ENTER 50 if the battery is fully discharged ( which you can achieve on lithium battery ) “ENTER 100”. (Lead-acid batteries can be discharged 50%)
  6. Select the charge controller type: are you using a PWM or MPPT charge controller?

After entering the information, click “Calculate” button to find out how long it will take to charge a 100ah lithium battery.

Example: How Long To Charge 100Ah Battery With 200 watt Solar Panel?

Let’s say you have a 12v 100ah lead-acid battery, 200 watt solar panel, and a PWM charge controller

200-watt solar panel will take about 4.4 peak sun hours to fully charge a 12v 100ah lead-acid battery from 50% depth of discharge using a PWM charge controller.

if you’re a noob, i would suggest you watch this full video to get a complete understanding of electricity basics.

Manual Calculation

Follow these steps to calculate the 100ah battery charge time with 200 watt solar panel

Step 1:

convert the battery capacity from amp-hours (Ah) to watt-hours (Wh) by multiplying the battery capacity (Ah) by battery volts. let’s say you have a 12v 100ah battery

Battery capacity in watt-hours = 100 * 12 = 1200wh or 1.2 kwh 

Step 2:

Multiply the battery capacity watt-hours by the battery depth of discharge %. let’s suppose you have a lead-acid battery with a 50% depth of discharge limit (DoD).

Discharged battery capacity in watt-hours =  1200 * 50% = 600wh

Step 3:

Multiply the discharged battery capacity (Wh) by 1.15 for lead-acid and 1.02 for lithium battery ( Battery charge efficiency rate, lead-acid; 85% efficient, lithium-ion; 98% efficient ).

Energy required to charge the battery = 600 * 1.15 = 690 watt-hours

Step 4:

Multiply the solar panel wattage by 80% to into account system losses. let’s suppose you have a 200 watt solar panel

Average solar panel output = 200 * 80% = 160 watts

Step 5:

Multiply the average solar panel output by the charge controller efficiency rate ( PWM; 80%, MPPT; 98% ). Let’s say you have an MPPT charge controller

Solar panel output after charge controller = 160 * 98% = 156.8 watts

Step 6:

Divide the Energy required to charge the battery by the solar panel output value after the charge controller.

Solar panel size required = 690 / 156.8 = 4.4 hours 

How Long Will a 200 watt Solar Panel Take To Charge A 100Ah Battery? – Charts

Here are some charts about how many peak sun hours will a 200 watt solar panel will take to charge a 12v, 24, and 48v 100ah lead-acid or lithium battery.

12v 100Ah Battery Charge Time With 200 watt Solar Panel

Solar Panel Size 12v 100ah Battery Type Charge Controller Type Est. Charge Time
200 watt lead-acid PWM 5.1 peak sun hours
200 watt Lithium (LiFePO4) PWM 9.1 peak sun hours
200 watt lead-acid MPPT 4.2 peak sun hours
200 watt Lithium (LiFePO4) MPPT 7.5 peak sun hours

Summary

  • 12v 100ah lead-acid battery will take about 5.1 peak sun hours to get fully charged from 50% depth of discharge with 200-watt solar panel using a PWM charge controller
  • 12v 100ah lithium (LiFPO4) battery will take about 9.1 peak sun hours to get fully charged from 100% depth of discharge with 200 watt solar panel using a PWM charge controller

24v 100Ah Battery Charge Time With 200 watt Solar Panel

Solar Panel Size 24v 100ah Battery Type Charge Controller Type Est. Charge Time
200 watt lead-acid PWM 10 peak sun hours
200 watt Lithium (LiFePO4) PWM 18 peak sun hours
200 watt lead-acid MPPT 8.5 peak sun hours
200 watt Lithium (LiFePO4) MPPT 15 peak sun hours

Summary

  • 24v 100ah lead-acid battery will take about 8.5 peak sun hours to get fully charged from 50% depth of discharge with 200-watt solar panel using an MPPT charge controller
  • 24v 100ah lithium (LiFPO4) battery will take about 15 peak sun hours to get fully charged from 100% depth of discharge with 200 watt solar panel using an MPPT charge controller

48v 100Ah Battery Charge Time With 200 watt Solar Panel

Solar Panel Size 48v 100ah Battery Type Charge Controller Type Est. Charge Time
200 watt lead-acid PWM 21 peak sun hours
200 watt Lithium (LiFePO4) PWM 37 peak sun hours
200 watt lead-acid MPPT 17 peak sun hours
200 watt Lithium (LiFePO4) MPPT 30 peak sun hours

Summary

  • 48v 100ah lead-acid battery will take about 17 peak sun hours to get fully charged from 50% depth of discharge with 200-watt solar panel using an MPPTcharge controller
  • 48v 100ah lithium (LiFPO4) battery will take about 30 peak sun hours to get fully charged from 100% depth of discharge with 200 watt solar panel using an MPPT charge controller

What Are Solar Peak Sun Hours?

Before explaining peak sun hours and why to use them, first, let’s see how solar panels are rated.

“ Solar panels are designed to produce their rated wattage output under standard test conditions – STC ”

STC includes: 

  • 1000 watts per meter square (1kw/m2) of sunlight intensity hitting the solar panels directly
  • 25oC temperature 

So to calculate the sunlight intensity we use peak sun hour as a reference. 

  • 1 peak sun hour = Average of 1kw/meter2 of sunlight intensity for one hour.

This number will depend on the location to location. To calculate how many peak sun hours your city receives use this PVwatt solar calculator.

Step 1: Enter your full address of just a city name & Click GO

How to calculate peak sun hours

Step 2: Click on results

How to calculate peak sun hours

Now you’d be able to see the total amount of solar radiation your location receives per day (from month to month)

How many peak sun hours in florida?

Note! it would have to place my solar panels all day long under sunlight to get those total solar radiations per day. 

Read the below-mentioned post to find out how much power output you can expect from your solar panels during peak sun hours. and also some tips to increase the solar panel’s output.

Must Read: Solar Panel Output Calculator – Average Solar Panel Output?

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I'm an experienced Sales Consultant with a demonstrated history of working in the renewables and environment industry. Skilled in Photography, Customer Service, and Sales.