You need about 100-120 watts of solar panels to fully charge a 12v 60ah lead-acid battery from 50% depth of discharge and 180-230 watts of solar panels to fully charge a 12v 70ah lithium (LiFePO4) battery from 100% depth of discharge in a day.
”What size solar panel do you need to charge a 60ah lead-acid or lithium battery?” Use the calculator given below to find out.
Solar Panel Size Calculator For 60ah Battery
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.
- 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 60ah Battery?
To find out what size solar panel you’d need to charge a 60ah battery, enter the following info into the calculator (located at the top of this page)
- Battery Capacity: in this case, it’ll be 60
- Battery Volts: is this a 12, or 24 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 60ah battery.
Suppose you have a 12v 60ah lithium battery with 100% depth of discharge and a PWM charge controller. You want to recharge your battery in one day (during winter) and your location receives 5 hours of peak sunlight
You’d need a 210 watt solar panel to fully charge a 12v 60ah lithium (LiFePO4) battery from 100% depth of discharge in 5 peak sun hours using a PWM charge controller.
Read the below post to find out how fast you can charge your battery.
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 ”
- 1000 watts per meter square (1kw/m2) of sunlight intensity hitting the solar panels directly
- 25oC temperature
- 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
Step 2: Click on results
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.
What Size Solar Panel To Charge 12v 60ah Lead-acid Battery?
|Charge Time||Charge Controller Type||Required Solar Panel|
|4 peak sun hours||PWM||150 watts|
|5 peak sun hours||PWM||120 watts|
|10 peak sun hours||PWM||60 watts|
|15 peak sun hours||PWM||40 watts|
|20 peak sun hours||PWM||30 watts|
|25 peak sun hours||PWM||25 watts|
|4 peak sun hours||MPPT||125 watts|
|5 peak sun hours||MPPT||100 watts|
|10 peak sun hours||MPPT||50 watts|
|15 peak sun hours||MPPT||35 watts|
|20 peak sun hours||MPPT||25 watts|
|25 peak sun hours||MPPT||20 watts|
- You need around 150 watts of solar panels to charge a 12V 60Ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with a PWM charge controller
- You need around 125 watts of solar panels to charge a 12V 60Ah lead-acid battery from 50% depth of discharge in 4 peak sun hours with an MPPT charge controller
What Size Solar Panel To Charge 12v 60ah Lithium (LiFePO4) Battery?
|Charge Time||Charge Controller Type||Required Solar Panel|
|4 peak sun hours||PWM||260 watts|
|5 peak sun hours||PWM||210 watts|
|10 peak sun hours||PWM||105 watts|
|15 peak sun hours||PWM||70 watts|
|20 peak sun hours||PWM||50 watts|
|25 peak sun hours||PWM||40 watts|
|4 peak sun hours||MPPT||220 watts|
|5 peak sun hours||MPPT||175 watts|
|10 peak sun hours||MPPT||90 watts|
|15 peak sun hours||MPPT||60 watts|
|20 peak sun hours||MPPT||45 watts|
|25 peak sun hours||MPPT||35 watts|
- You need around 250 watts of solar panels to charge a 12V 60Ah lithium battery from 100% depth of discharge in 4 peak sun hours with a PWM charge controller
- You need around 200 watts of solar panels to charge a 12V 60Ah lithium battery from 100% depth of discharge in 4 peak sun hours with an MPPT charge controller
How To Choose The Right Size Charge Controller?
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
- Divide the solar panel rated wattage by battery volts (e.g by 12 for 12v battery and so on…)
- Now add an extra 25% to the result value to keep the system safe in case of any fluctuations.
- Now the value will be the size of charge controller you’d need with your particular solar panel size to charge the battery.
let’s suppose you have a 200 watt solar panel and a 12v battery. the calculation will look like this.
200 / 12 = 16.6A
16.6 + 25% or 16.6 * 1.25 = 20.8A
you’d need a 20A charge controller with a 200 watt solar panel to charge the 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.
60Ah Battery: FAQ’s
What does 60Ah mean on a battery?
12v 60ah battery means 730 watt-hours of power. calculate the watts in a battery using this formula ( battery ah * battery volts )
How many solar panels does it take to charge a 60AH battery?
12v 60ah battery will need about 90 watts of solar panels to charge in 10 peak sun hours from 0-100%.