What Size Solar Panel To Charge 150ah Battery? + Calculator

You need about 200-300 watts of solar panels to fully charge a 12v 150ah lead-acid battery from 50% depth of discharge and 400-500 watts of solar panels to fully charge a 12v 150ah lithium (LiFePO4) battery from 100% depth of discharge in a day.

” What size solar panel do you need to charge a 150ah lead-acid or lithium battery? ” Enter the battery specs, the number of desired peak sun hours to charge your battery, and the charge controller type that you’re using (PWM or MPPT) into the calculator (given below) to find out.

Or check the charts at the bottom of this page to find out what size solar panel you’d need according to different charge time and battery types.

Solar Panel Size Calculator For Battery

Battery Capacity (Amp-hours)
Ah
Battery Voltage
V
Battery Type
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

How Much Solar Power Required To Charge 150ah Battery?

To find out what size solar panel you’d need to charge a 150ah battery, enter the following info into the calculator (located at the top of this page) 

  • Battery Capacity: in this case, it’ll be 150
  • Battery Volts: is this a 12, 24, 36, or 48 volts battery? Enter the number accordingly
  • 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 150ah battery. 

Example 

Suppose you have a 12v 150ah lead-acid battery with 50% depth of discharge and an MPPT charge controller. You want to recharge your battery in one day and your location receives 6 hours of peak sunlight

What Size Solar Panel To Charge 150ah Battery?

You’d need a 210 watt solar panel to fully charge a 12v 150ah lead-acid battery from 50% depth of discharge in 6 peak sun hours using an MPPT charge controller.

Read the below post to find out how fast you can charge your battery.

Related Post: Guide: Maximum Charging Current & Voltage For 12v Battery

How To Calculate 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: 

  1. 1000 watts per meter square (1kw/m2) of sunlight intensity hitting the solar panels directly
  2. 25oC temperature 
  3. No wind

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)

Average Solar Panel Output In Peak Sun Hour 

As we know that solar panels are rated their power under a controlled laboratory environment. But in the real world, there will be some power losses 

These power losses will occur due to various reasons, here are some examples

  • Manufacturer’s output tolerance (+-3%)
  • Dirt and grime on panels (+-5%)
  • DC cable loss (+-3%)
  • Temperature derating (+-10 – 20%)

On average. A solar panel will deliver about 80% of its rated output value in real-world conditions.

This percentage is based on my personal experience with 400 watt solar panels. I collected the 30 days of total output from the solar panels and divide it by that month’s peak sun hours. 

Yes, there’ll be sometimes when you’ll get 100% output from the solar panel but it’s rarely gonna happen and will last for a few minutes 

I have a detailed post about this topic and shared some tips to get the maximum output from your solar panels.

Related Post: Solar Panel Output Calculator – Average Solar Panel Output?

What Size Solar Panel To Charge 12v 150ah Lead-Acid Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM370 watts
5 peak sun hoursPWM300 watts
6 peak sun hoursPWM250 watts
10 peak sun hoursPWM150 watts
15 peak sun hoursPWM100 watts
20 peak sun hoursPWM75 watts
4 peak sun hoursMPPT310 watts
5 peak sun hoursMPPT250 watts
6 peak sun hoursMPPT210 watts
10 peak sun hoursMPPT125 watts
15 peak sun hoursMPPT80 watts
20 peak sun hoursMPPT60 watts

Summary

  • You need around 300 watts of solar panels to charge a 12V 150Ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 250 watts of solar panels to charge a 12V 150Ah 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 150ah Lithium (LiFePO4) Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM660 watts
5 peak sun hoursPWM520 watts
6 peak sun hoursPWM440 watts
10 peak sun hoursPWM260 watts
15 peak sun hoursPWM175 watts
20 peak sun hoursPWM130 watts
4 peak sun hoursMPPT550 watts
5 peak sun hoursMPPT440 watts
6 peak sun hoursMPPT365 watts
10 peak sun hoursMPPT220 watts
15 peak sun hoursMPPT145 watts
20 peak sun hoursMPPT110 watts

Summary

  • You need around 520 watts of solar panels to charge a 12V 150Ah lithium battery from 100% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 440 watts of solar panels to charge a 12V 150Ah lithium battery from 100% depth of discharge in 5 peak sun hours with an MPPT charge controller

What Size Solar Panel To Charge 24v 150ah Lead-Acid Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM750 watts
5 peak sun hoursPWM600 watts
6 peak sun hoursPWM500 watts
10 peak sun hoursPWM300 watts
15 peak sun hoursPWM200 watts
20 peak sun hoursPWM150 watts
4 peak sun hoursMPPT620 watts
5 peak sun hoursMPPT500 watts
6 peak sun hoursMPPT415 watts
10 peak sun hoursMPPT250 watts
15 peak sun hoursMPPT165 watts
20 peak sun hoursMPPT125 watts

Summary

  • You need around 600 watts of solar panels to charge a 24V 150Ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 500 watts of solar panels to charge a 24V 150Ah 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 150ah Lithium (LiFePO4) Battery?

Charge TimeCharge Controller TypeRequired Solar Panel
4 peak sun hoursPWM1310 watts
5 peak sun hoursPWM1050 watts
6 peak sun hoursPWM870 watts
10 peak sun hoursPWM520 watts
15 peak sun hoursPWM350 watts
20 peak sun hoursPWM260 watts
4 peak sun hoursMPPT1090 watts
5 peak sun hoursMPPT870 watts
6 peak sun hoursMPPT730 watts
10 peak sun hoursMPPT440 watts
15 peak sun hoursMPPT290 watts
20 peak sun hoursMPPT220 watts

Summary

  • You need around 1050 watts or 1.05 kWh of solar panels to charge a 24V 150Ah lithium battery from 100% depth of discharge in 5 peak sun hours with a PWM charge controller
  • You need around 870 watts of solar panels to charge a 24V 150Ah lithium battery from 100% depth of discharge in 5 peak sun hours with an MPPT charge controller

150Ah Battery: FAQs

How many watts is a 150Ah battery?

12v 150ah battery is equal to 1800 watt-hours. to calculate the battery watts use this formula ( battery Ah * battery volts )

How long does it take to charge a 150Ah battery?

150ah battery will take between 5-20 hours to charge, the exact number will depend on the size of the solar panel.

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.