Use our solar panel size calculator to find out what size solar panel you need to charge your battery in desired time.
Simply enter the battery specifications, including Ah, volts, and battery type. Also the charge controller type and desired charge time in peak sun hours into our calculator to get your results.
Solar Panel Size Calculator
Note: If you already have a solar panel and want to know how long it will take to charge your battery, use our solar battery charge time calculator.
Calculator Assumptions
- Battery charge efficiency rate: Lead-acid - 85%, AGM - 85%, Lithium (LiFePO4) - 99%
- Charge controller efficiency: PWM - 80%; MPPT - 98% [1]
- Solar Panels Efficiency during peak sun hours: 80%, this means that a 100 watt solar panel will produce 80 watts during peak sun hours. Click here to read more.
- There are no devices drawing power from the battery during the charging process.
how to use our solar panel size calculator?
1. Enter battery Capacity in amp-hours (Ah): For a 100ah battery, enter 100. If the battery capacity is mentioned in watt-hours (Wh), divide Wh by the battery's voltage (v).
2. Enter battery volts (V): Is this a 12, 24, or 48-volt battery?
3. Select battery type: Is this a lead-acid, AGM, or lithium-ion (LiFePO4) battery?
4. Enter battery depth of discharge (DoD): Battery DoD This is the percentage of the battery discharged relative to the total battery capacity. For half discharged battery you ENTER 50, and if the battery is fully discharged which you can achieve on a lithium battery, ENTER 100.
5. Select charge controller type: Are you using a PWM or MPPT charge controller to charge the battery?
6. Enter 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? (click here to read more about peak sun hours, and how many peak sun hours your area receives).
Click “Calculate” button to get the result.
Note: Scroll to the bottom of this page (or click here) to find out how you can calculate the size of solar panels in the future without any need for an online calculator.
for Example
Let's suppose, you have:
- Battery capacity: 50ah
- Battery voltage: 12v
- Battery type: Lithium (LiFePO4)
- Battery depth of discharge: Fully discharged (100%)
- Charge controller: MPPT
- Desired charge time: 6 peak sun hours
Result: You need about 120 watt solar panel to fully charge a 12v 50ah lithium (LiFePO4) battery from 100% depth of discharge in 6 peak sun hours.
Read the below post to find out how fast you can charge your battery.
Related Post: Guide: Maximum Charging Current & Voltage For 12v Battery
6 steps to calculate the Perfect solar panel size For battery
Follow these 6 steps to calculate the estimated required solar panel size to recharge your battery in desired time frame.
Steps
Batteries are quite complex, making it nearly impossible to calculate the exact solar panel size needed to recharge them in a desired timeframe. However, I have covered the most impactful real-world factors in these steps.
1- Multiply the battery amp-hours (ah) by battery volts to convert the battery capacity into watt-hours (Wh). Let's suppose you have a 12v 50ah battery.
Battery capacity in Wh = 50 × 12 = 600wh2- Multiply the battery watt-hours by the battery depth of discharge limit. Lead-acid, AGM, and gel batteries come with a depth of discharge limit of 50%, and lithium batteries with 100% DoD. Let's say you have a 12v 50ah lead-acid battery.
Discharged Battery capacity in Wh = 600 × 0.5 = 300wh3- Divide the battery capacity after DoD by the battery's charge efficiency rate (lithium: 99%; Lead-acid: 85%).
Power required to charge the battery = 300 ÷ 85% or 300 × 1.15 = 345wh4- Divide the battery capacity value (after charge adding efficiency factor) by the desired number of charge peak sun hours. Let's suppose you want to recharge your battery in 5 peak sun hours.
Solar power required in peak sun hour = 345 ÷ 5 = 69 watts5- Divide the solar power required in peak sun hour by the charge controller efficiency (PWM: 80%; MPPT 98%). Let's suppose you're using a PWM charge controller.
Solar power required after charge controller = 69 ÷ 80% = 86.25 watts6- Add 20% to the solar power required after the controller to cover up the solar panel inefficiency.
Solar panel Required = 86.2 + 20% = 103 wattsThat's it! easy right?
Must Read: Battery Charge And Discharge Rate Calculator: C-Rating To Amps
Now I’ll show you tables and charts showing recommended solar panel sizes to charge different capacity batteries in different peak sun hours.
What Size Solar Panel To Charge 12v Battery?
Here's a chart about what size solar panel you need to charge different capacity 12v lead-acid and Lithium (LiFePO4) batteries in 6 peak sun hours using an MPPT charge controller.
| 12v Battery Size (Ah) | Battery Type | Required Solar Panel Size |
|---|---|---|
| 20Ah | Lead-acid | 30 watts |
| 50Ah | Lead-acid | 70 watts |
| 60Ah | Lead-acid | 80 watts |
| 80Ah | Lead-acid | 110 watts |
| 100Ah | Lead-acid | 140 watts |
| 120Ah | Lead-acid | 165 watts |
| 140Ah | Lead-acid | 190 watts |
| 150Ah | Lead-acid | 210 watts |
| 170Ah | Lead-acid | 235 watts |
| 200Ah | Lead-acid | 280 watts |
| 220Ah | Lead-acid | 300 watts |
| 250Ah | Lead-acid | 345 watts |
| 300Ah | Lead-acid | 415 watts |
| 350Ah | Lead-acid | 480 watts |
| 400Ah | Lead-acid | 550 watts |
| 20Ah | Lithium (LiFePO4) | 50 watts |
| 50Ah | Lithium (LiFePO4) | 120 watts |
| 60Ah | Lithium (LiFePO4) | 145 watts |
| 80Ah | Lithium (LiFePO4) | 190 watts |
| 100Ah | Lithium (LiFePO4) | 240 watts |
| 120Ah | Lithium (LiFePO4) | 290 watts |
| 150Ah | Lithium (LiFePO4) | 360 watts |
| 170Ah | Lithium (LiFePO4) | 410 watts |
| 200Ah | Lithium (LiFePO4) | 485 watts |
| 220Ah | Lithium (LiFePO4) | 530 watts |
| 250Ah | Lithium (LiFePO4) | 600 watts |
| 300Ah | Lithium (LiFePO4) | 730 watts |
| 350Ah | Lithium (LiFePO4) | 850 watts |
| 400Ah | Lithium (LiFePO4) | 970 watts |
Summary
- You need around 200-300 watts of solar panels to charge most of the 12V lead-acid batteries from 50% depth of discharge in 6 peak sun hours with an MPPT charge controller.
- You need around 400-550 watts of solar panels to charge most of the 12V lithium (LiFePO4) batteries from 100% depth of discharge in 6 peak sun hours with an MPPT charge controller.
What Size Solar Panel To Charge 24v Battery?
Here's a chart about what size solar panel you need to charge different capacity 24v lead-acid & Lithium (LiFePO4) batteries in 6 peak sun hours using an MPPT charge controller.
| 24v Battery capacity (Ah) | Battery Type | Required Solar Panel Size |
|---|---|---|
| 50Ah | Lead-acid | 140 watts |
| 100Ah | Lead-acid | 280 watts |
| 120Ah | Lead-acid | 330 watts |
| 150Ah | Lead-acid | 415 watts |
| 200Ah | Lead-acid | 550 watts |
| 300Ah | Lead-acid | 930 watts |
| 400Ah | Lead-acid | 1100 watts |
| 50Ah | Lithium (LiFePO4) | 240 watts |
| 100Ah | Lithium (LiFePO4) | 480 watts |
| 120Ah | Lithium (LiFePO4) | 580 watts |
| 150Ah | Lithium (LiFePO4) | 730 watts |
| 200Ah | Lithium (LiFePO4) | 930 watts |
| 300Ah | Lithium (LiFePO4) | 1450 watts |
| 400Ah | Lithium (LiFePO4) | 1940 watts |
Summary
- You need around 300-500 watts of solar panels to charge most of the 24V lead-acid batteries from 50% depth of discharge in 6 peak sun hours with an MPPT charge controller.
- You need around 600-900 watts of solar panels to charge most of the 24V lithium (LiFePO4) batteries from 100% depth of discharge in 6 peak sun hours with an MPPT charge controller.
Full article: What Size Solar Panel To Charge 24v Battery?
What Size Solar Panel To Charge 48V Battery?
Here's a chart about what size solar panel you need to charge different capacity 48v lead-acid & Lithium (LiFePO4) batteries in 6 peak sun hours using an MPPT charge controller.
| 24v Battery capacity (Ah) | Battery Type | Required Solar Panel Size |
|---|---|---|
| 50Ah | Lead-acid | 280 watts |
| 100Ah | Lead-acid | 550 watts |
| 120Ah | Lead-acid | 660 watts |
| 150Ah | Lead-acid | 830 watts |
| 200Ah | Lead-acid | 1100 watts |
| 300Ah | Lead-acid | 1660 watts |
| 400Ah | Lead-acid | 2200 watts |
| 50Ah | Lithium (LiFePO4) | 490 watts |
| 100Ah | Lithium (LiFePO4) | 970 watts |
| 120Ah | Lithium (LiFePO4) | 1160 watts |
| 150Ah | Lithium (LiFePO4) | 1460 watts |
| 200Ah | Lithium (LiFePO4) | 1940 watts |
| 300Ah | Lithium (LiFePO4) | 2900 watts |
| 400Ah | Lithium (LiFePO4) | 3880 watts |
Summary
- You need around 800-1000 watts of solar panels to charge most of the 48V lead-acid batteries from 50% depth of discharge in 6 peak sun hours with an MPPT charge controller.
- You need around 1600-2000 watts of solar panels to charge most of the 48V lithium batteries from 100% depth of discharge in 6 peak sun hours with an MPPT charge controller.
What Size Solar Panel To Charge 120Ah Battery?
Here's a chart about what size solar panel you need to charge your 12v 120ah lead-acid (50% depth of discharge) and lithium battery (100% depth of discharge) with different peak sun hours and using an MPPT charge controller.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 250 watts |
| 5 peak sun hours | Lead-acid | 200 watts |
| 10 peak sun hours | Lead-acid | 100 watts |
| 15 peak sun hours | Lead-acid | 65 watts |
| 20 peak sun hours | Lead-acid | 50 watts |
| 25 peak sun hours | Lead-acid | 40 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 440 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 350 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 175 watts |
| 15 peak sun hours | Lithium (LiFePO4) | 115 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 90 watts |
| 25 peak sun hours | Lithium (LiFePO4) | 70watts |
Summary
- You need around 200 watts of solar panels to charge a 12V 120ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with an MPPT charge controller.
- You need around 350 watts of solar panels to charge a 12V 120ah lithium battery from 100% depth of discharge in 5 peak sun hours with an MPPT charge controller.
Full article: Charging 120Ah Battery Guide
What Size Solar Panel To Charge 100Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 100ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 210 watts |
| 5 peak sun hours | Lead-acid | 165 watts |
| 6 peak sun hours | Lead-acid | 140 watts |
| 10 peak sun hours | Lead-acid | 80 watts |
| 15 peak sun hours | Lead-acid | 55 watts |
| 20 peak sun hours | Lead-acid | 40 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 360 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 290 watts |
| 6 peak sun hours | Lithium (LiFePO4) | 240 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 150 watts |
| 15 peak sun hours | Lithium (LiFePO4) | 100 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 70 watts |
Summary
- You need around 210 watts of solar panels to charge a 12V 100ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with an MPPT charge controller.
- You need around 360 watts of solar panels to charge a 12V 100ah Lithium (LiFePO4) battery from 100% depth of discharge in 4 peak sun hours with an MPPT charge controller.
What Size Solar Panel To Charge 50Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 50ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 100 watts |
| 5 peak sun hours | Lead-acid | 80 watts |
| 6 peak sun hours | Lead-acid | 70 watts |
| 10 peak sun hours | Lead-acid | 40 watts |
| 15 peak sun hours | Lead-acid | 30 watts |
| 20 peak sun hours | Lead-acid | 20 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 180 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 145 watts |
| 6 peak sun hours | Lithium (LiFePO4) | 121 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 70 watts |
| 15 peak sun hours | Lithium (LiFePO4) | 50 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 35 watts |
Summary
- You need around 100 watts of solar panels to charge a 12V 50ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with an MPPT charge controller.
- You need around 180 watts of solar panels to charge a 12V 50ah Lithium (LiFePO4) battery from 100% depth of discharge in 4 peak sun hours with an MPPT charge controller.
Related Post: How Long Will A 50Ah Battery Last?
What Size Solar Panel To Charge 20Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 20ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 40 watts |
| 5 peak sun hours | Lead-acid | 33 watts |
| 6 peak sun hours | Lead-acid | 27 watts |
| 10 peak sun hours | Lead-acid | 16 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 70 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 60 watts |
| 6 peak sun hours | Lithium (LiFePO4) | 50 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 30 watts |
Summary
- You need around 40 watts of solar panels to charge a 12V 20ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with an MPPT charge controller.
- You need around 70 watts of solar panels to charge a 12V 20ah Lithium (LiFePO4) battery from 100% depth of discharge in 4 peak sun hours with an MPPT charge controller.
What Size Solar Panel To Charge 150Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 150ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 310 watts |
| 5 peak sun hours | Lead-acid | 250 watts |
| 6 peak sun hours | Lead-acid | 210 watts |
| 10 peak sun hours | Lead-acid | 125 watts |
| 20 peak sun hours | Lead-acid | 60 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 550 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 440 watts |
| 6 peak sun hours | Lithium (LiFePO4) | 360 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 220 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 110 watts |
Summary
- You need around 310 watts of solar panels to charge a 12V 150ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with an MPPT charge controller.
- You need around 550 watts of solar panels to charge a 12V 150ah Lithium (LiFePO4) battery from 100% depth of discharge in 4 peak sun hours with an MPPT charge controller.
Full article: What Size Solar Panel To Charge 150ah Battery?
What Size Solar Panel To Charge 200Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 200ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 420 watts |
| 5 peak sun hours | Lead-acid | 330 watts |
| 10 peak sun hours | Lead-acid | 165 watts |
| 20 peak sun hours | Lead-acid | 80 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 730 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 580 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 290 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 150 watts |
Summary
- You need around 420 watts of solar panels to charge a 12V 200ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with an MPPT charge controller.
- You need around 730 watts of solar panels to charge a 12V 200ah Lithium (LiFePO4) battery from 100% depth of discharge in 4 peak sun hours with an MPPT charge controller.
Full article: What Size Solar Panel To Charge 200Ah Battery?
What Size Solar Panel To Charge 60Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 60ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 125 watts |
| 5 peak sun hours | Lead-acid | 100 watts |
| 10 peak sun hours | Lead-acid | 50 watts |
| 20 peak sun hours | Lead-acid | 25 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 220 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 175 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 90 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 40 watts |
Summary
- You need around 100 watts of solar panels to charge a 12V 60ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with an MPPT charge controller.
- You need around 175 watts of solar panels to charge a 12V 60ah Lithium (LiFePO4) battery from 100% depth in 5 peak sun hours with an MPPT charge controller.
Full article: What Size Solar Panel To Charge 60Ah Battery?
What Size Solar Panel To Charge 130Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 130ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 270 watts |
| 5 peak sun hours | Lead-acid | 220 watts |
| 10 peak sun hours | Lead-acid | 110 watts |
| 20 peak sun hours | Lead-acid | 50 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 470 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 380 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 190 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 100 watts |
Summary
- You need around 220 watts of solar panels to charge a 12V 130ah lead-acid battery from 50% depth of discharge in 5 peak sun hours with an MPPT charge controller.
- You need around 380 watts of solar panels to charge a 12V 130ah Lithium (LiFePO4) battery from 100% depth in 5 peak sun hours with an MPPT charge controller.
What Size Solar Panel To Charge 140Ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 140ah lead-acid & lithium battery using an MPPT charge controller with different peak sun hours of sunlight.
| Charge Time | Battery Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | Lead-acid | 290 watts |
| 5 peak sun hours | Lead-acid | 230 watts |
| 10 peak sun hours | Lead-acid | 115 watts |
| 20 peak sun hours | Lead-acid | 60 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 510 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 410 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 200 watts |
| 20 peak sun hours | Lithium (LiFePO4) | 100 watts |
Summary
- You need around 290 watts of solar panels to charge a 12V 140ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with an MPPT charge controller.
- You need around 510 watts of solar panels to charge a 12V 140ah Lithium (LiFePO4) battery from 100% depth in 4 peak sun hours with an MPPT charge controller.
Full article: What Size Solar Panel To Charge 140ah Battery?
