What Size Solar Panel To Charge 200Ah Battery? + Calculator

You need about 300-400 watts of solar panels to fully charge a 12v 200ah lead-acid battery from 50% depth of discharge and 550-700 watts of solar panels to fully charge a 12v 200ah lithium (LiFePO4) battery from 100% depth of discharge in a day.

”What size solar panel do you need to charge a 200ah lead-acid or lithium battery? ” use the calculator given below to find out.

Solar panel size calculator for 200ah battery

Battery Capacity (Amp-hours)
Ah
Battery Voltage
V
Battery Type
Battery Depth of Discharge (DoD)
%
Charge Controller Type
Desired Charge Time (Peak sun hours)
hours

Note: If you already have a solar panel and want to know how long it will take to charge your battery, use this solar battery charge time calculator.

Calculator Assumptions: 

  • Lead-acid Battery Charge efficiency rate: 85%
  • AGM Battery Charge efficiency rate: 85%
  • Lithium (LiFePO4) Charge efficiency rate: 99%
  • PWM charge controller: 80% efficient
  • MPPT charge controller: 98% efficient
  • Solar Panels Efficiency during peak sun hours: 80% (meaning a 100 watt solar panel will produce 80 watts during peak sun hours, i’ll explain why…)
  • Charge controller is the only load connected with the battery

What Size Solar Panel To Charge 12v 200ah Battery?

To find out what size solar panel you’d need to charge a 200ah battery, enter the following info into the calculator (located at the top of this page)

  • Battery Capacity: in this case, it’ll be 200
  • Battery Volts: is this a 12, 24, or 48 volt battery?
  • Battery Type: Select the battery type, is this a lead-acid, AGM, or lithium-ion (LiFePO4) battery?
  • Battery Depth of discharge 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)
  • Charge Controller Type: Are you using a PWM or MPPT charge controller to charge the battery? 
  • Desired Charge time (in peak sun hours): How fast would you like to charge your battery or how many peak sun hours your location receives? (keep reading i’ll explain how you can calculate the number of peak sun hours)  

After entering the information, click “Calculate” button to find the required size for a 200ah battery. 

Example 

Suppose you have a 12v 200ah lithium battery with 100% depth of discharge and an MPPT charge controller. You want to recharge your battery in one day (during summer days) and your location receives 6 hours of peak sunlight 

What Size Solar Panel To Charge 12v 200ah Battery?

You’d need about 490 watts of solar panels to fully charge a 12v 200ah lithium (LiFePO4) battery from 100% depth of discharge in 6 peak sun hours using an MPPT charge controller.

What Are Solar Peak Sun Hours?

Before getting into peak sun hours, let’s first 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
How many peak sun hours in florida?

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

Maximum Charging Current For 200Ah Battery

200Ah lithium (LiFePO4) specs

The maximum charging current for a 200Ah lithium battery is usually 100A and the ideal charging current for a lead-acid or AGM battery is 50A.

Charging a current more than ideal or maximum will increase the internal temperature in the battery cells which as a result will decrease the battery lifespan in the long run

Related post: Maximum Charging Current & Voltage For 12v Battery

What Size Solar Panel To Charge 12v 200ah Lead-Acid Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM500 watts
5 peak sun hoursPWM400 watts
10 peak sun hoursPWM200 watts
15 peak sun hoursPWM130 watts
20 peak sun hoursPWM100 watts
25 peak sun hoursPWM80 watts
4 peak sun hoursMPPT420 watts
5 peak sun hoursMPPT330 watts
10 peak sun hoursMPPT165 watts
15 peak sun hoursMPPT110 watts
20 peak sun hoursMPPT80 watts
25 peak sun hoursMPPT65 watts

Summary

  • You need around 400 watts of solar panels to charge a 12V 200ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 330 watts of solar panels to charge a 12V 200ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with an MPPT charge controller

What Size Solar Panel To Charge 12v 200ah Lithium (LiFePO4) Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM870 watts
5 peak sun hoursPWM700 watts
10 peak sun hoursPWM350 watts
15 peak sun hoursPWM230 watts
20 peak sun hoursPWM175 watts
25 peak sun hoursPWM140 watts
4 peak sun hoursMPPT730 watts
5 peak sun hoursMPPT580 watts
10 peak sun hoursMPPT290 watts
15 peak sun hoursMPPT195 watts
20 peak sun hoursMPPT145 watts
25 peak sun hoursMPPT115 watts

Summary

  • You need around 700 watts of solar panels to charge a 12V 200ah lithium battery from 100% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 580 watts of solar panels to charge a 12V 200ah lithium battery from 100% depth of discharge in 5 peak sun hours with an MPPT charge controller

What Size Solar Panel To Charge 24v 200ah Lead-Acid Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM990 watts
5 peak sun hoursPWM800 watts
6 peak sun hoursPWM660 watts
10 peak sun hoursPWM400 watts
15 peak sun hoursPWM270 watts
20 peak sun hoursPWM200 watts
4 peak sun hoursMPPT830 watts
5 peak sun hoursMPPT660 watts
6 peak sun hoursMPPT550 watts
10 peak sun hoursMPPT330 watts
15 peak sun hoursMPPT220 watts
20 peak sun hoursMPPT165 watts

Summary

  • You need around 800 watts of solar panels to charge a 24V 200ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 660 watts of solar panels to charge a 24V 200ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with an MPPT charge controller

What Size Solar Panel To Charge 24v 200ah Lithium (LiFePO4) Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM1750 watts
5 peak sun hoursPWM1400 watts
6 peak sun hoursPWM1160 watts
10 peak sun hoursPWM700 watts
15 peak sun hoursPWM465 watts
20 peak sun hoursPWM350 watts
4 peak sun hoursMPPT1450 watts
5 peak sun hoursMPPT1160 watts
6 peak sun hoursMPPT970 watts
10 peak sun hoursMPPT580 watts
15 peak sun hoursMPPT390 watts
20 peak sun hoursMPPT290 watts

Summary

  • You need around 1400 watts or 1.4kwh of solar panels to charge a 24V 200ah lithium battery from 100% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 1160 watts or 1.16kwh of solar panels to charge a 24V 200ah lithium battery from 100% depth of discharge in 5 peak sun hours with an MPPT charge controller

What Size Charge Controller To Charge 200ah Battery?

The job of the charge controller is to regulate the voltage coming from the solar panels to safely charge the battery and prevent the battery to be overcharged.

To select the right size charge controller according to your solar panel size. Follow these 2 steps

  1. Divide the solar panel rated wattage by battery volts (e.g by 12 for 12v battery and so on…)
  2. Now add an extra 25% to the result value to keep the system safe in case of any fluctuations.
  3. Now the value will be the size of charge controller you’d need with your particular solar panel size to charge the battery.

For Example

let’s suppose you have an 400-watt of solar panels and a 12v 200ah battery. the calculation will look like this.

400 / 12 = 33.3A
16.6 + 25% or 16.6 * 1.25 = 41.6A

you’d need a 40A MPPT charge controller with a 400-watt solar panel to charge a 12v 200ah battery.

PWM Vs MPPT

– PWM Charge Controller

will only decrease the voltage coming from the solar panels and will not increase the amps (current).

which as a result will cause power losses and which makes the PWM charge controllers 20-30% less efficient.

The formula to power is… ( Watts = amps * volts )

Note! a 12v solar panel will produce about 18 volts under direct sunlight conditions... and the amps will be lower.

– MPPT Charge Controller

An MPPT charge controller will not only decrease the voltage coming from the solar panel to charge the battery but will also increase the amps to cover up the losses.

which makes them 98-99% more efficient than a PWM charge controller.

Pro Tip: if your solar panel system is higher then 100 watts then i would suggest using an MPPT charge controller. 

Related Post: How Many Watts Can A Charge Controller Handle?

200ah Battery: FAQ’s

What does 200Ah battery mean?

12v 200ah battery means 2400 watt-hours of power. calculate the watts in a battery using this formula ( battery ah * battery volts )

how long does it take to charge a 200ah battery

200ah battery will take about 5-20 hours to get fully charged. the exact value will depend on the size of the solar panel

How many solar panels do I need to charge a 200Ah battery in 5 hours?

you need 330 watts of solar panels to fully charge a 12v 200ah lead-acid battery from 50% depth of discharge in 5 hours and 580 watts of solar panels to charge a 12v 200ah lithium battery from 100% depth of discharge in 5 hours with an MPPT charge controller.

Keep Reading…

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.

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