Use our solar panel size calculator to find out what size solar panel you need to charge a 140ah battery.
calculate solar panel size to charge 140ah battery
Note: Not sure what peak sun hours are and how to calculate them? Click here to read more…
Calculator Assumptions
- Battery charge efficiency rate: Lead acid: 85%; Lithium (LiFePO4): 99% (source)
- Charge controller efficiency: MPPT: 98%; PWM: 80%
- Solar panel efficiency in real world conditions during peak sun hour: 80%
- There is no load connected to the battery when charging.
Battery depth of discharge is the percentage of the battery that has been discharged relative to the total battery capacity. for half discharged battery ENTER 50, if the battery is fully discharged (which you can achieve on a lithium battery), ENTER 100.
Desired charge time (in peak sun hours): How fast would you like to charge your battery in peak sun hours?
Example
Let’s suppose…
- Battery capacity: 140ah
- Battery volts: 12v
- Battery type: Lithium
- Battery depth of discharge: 100% (fully discharged)
- Charge controller: MPPT
- Desire charge time: 7 peak sun hours
Click “CALCULATE” button to get the result.
You need about 300 watt solar panel to charge a 12v 140ah lithium (LiFePO4) battery from 100% depth of discharge in 7 peak sun hours.
Use our battery charge and discharge calculator to find out how quickly you should charge or discharge your battery.
what are peak sun hours?
1 peak sun hour = 1000 watt/meter2 of solar radiation.
Solar panels produce their rated power output under standard test conditions. Which include: 1kW/m2 solar radiation, Temperature: 25oC, Air mass (AM): 1.5.
Using peak sun hours will give us the most accurate information about what we can expect from our solar panels.
Luckily there are some organizations that have collected years of data on solar radiation for every location on earth. NREL is one of them — Use their PV watts calculator to find out how many peak sun hours your location receives.
What Size Solar Panel To Charge 140ah Battery?
Here are some tables on what size solar panel you need to charge 140ah lead acid or lithium battery in different peak sun hours.
12v 140ah lead acid battery
| Charge Time | Charge Controller Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | PWM | 350 watts |
| 5 peak sun hours | PWM | 280 watts |
| 10 peak sun hours | PWM | 140 watts |
| 15 peak sun hours | PWM | 95 watts |
| 20 peak sun hours | PWM | 70 watts |
| 25 peak sun hours | PWM | 55 watts |
| 4 peak sun hours | MPPT | 290 watts |
| 5 peak sun hours | MPPT | 230 watts |
| 10 peak sun hours | MPPT | 115 watts |
| 15 peak sun hours | MPPT | 80 watts |
| 20 peak sun hours | MPPT | 60 watts |
| 25 peak sun hours | MPPT | 45 watts |
Summary
- You need about 230 watt solar panel to charge a 12v 140ah lead acid battery in 5 peak sun hours with an MPPT charge controller.
12v 140Ah Lithium (LiFePO4) Battery
| Charge Time | Charge Controller Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | PWM | 610 watts |
| 5 peak sun hours | PWM | 490 watts |
| 10 peak sun hours | PWM | 245 watts |
| 15 peak sun hours | PWM | 160 watts |
| 20 peak sun hours | PWM | 120 watts |
| 25 peak sun hours | PWM | 100 watts |
| 4 peak sun hours | MPPT | 510 watts |
| 5 peak sun hours | MPPT | 410 watts |
| 10 peak sun hours | MPPT | 200 watts |
| 15 peak sun hours | MPPT | 135 watts |
| 20 peak sun hours | MPPT | 100 watts |
| 25 peak sun hours | MPPT | 80 watts |
Summary
- You need about 400 watt solar panel to charge a 12v 140ah lithium battery in 5 peak sun hours with an MPPT charge controller.
24v 140ah lead acid battery
| Charge Time | Charge Controller Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | PWM | 700 watts |
| 5 peak sun hours | PWM | 560 watts |
| 6 peak sun hours | PWM | 460 watts |
| 10 peak sun hours | PWM | 280 watts |
| 15 peak sun hours | PWM | 185 watts |
| 20 peak sun hours | PWM | 140 watts |
| 4 peak sun hours | MPPT | 580 watts |
| 5 peak sun hours | MPPT | 460 watts |
| 6 peak sun hours | MPPT | 390 watts |
| 10 peak sun hours | MPPT | 230 watts |
| 15 peak sun hours | MPPT | 155 watts |
| 20 peak sun hours | MPPT | 115 watts |
Summary
- You need about 460 watt solar panel to charge a 24v 140ah lead acid battery in 5 peak sun hours with an MPPT charge controller.
24v 140Ah Lithium (LiFePO4) Battery
| Charge Time | Charge Controller Type | Required Solar Panel |
|---|---|---|
| 4 peak sun hours | PWM | 1220 watts |
| 5 peak sun hours | PWM | 980 watts |
| 6 peak sun hours | PWM | 815 watts |
| 10 peak sun hours | PWM | 490 watts |
| 15 peak sun hours | PWM | 325 watts |
| 20 peak sun hours | PWM | 250 watts |
| 4 peak sun hours | MPPT | 1020 watts |
| 5 peak sun hours | MPPT | 815 watts |
| 6 peak sun hours | MPPT | 670 watts |
| 10 peak sun hours | MPPT | 410 watts |
| 15 peak sun hours | MPPT | 270 watts |
| 20 peak sun hours | MPPT | 200 watts |
Summary
- You need about 810 watt solar panel to charge a 24v 140ah lithium battery in 5 peak sun hours with an MPPT charge controller.
