How many watt solar panels you need to charge a 220ah battery will depend on these factors:
- How quickly you can want to charge your battery?
- What type of battery do you have?
- What type of charge controller do you have?
Need an easy solution? Use our solar panel size calculator to find out.
calculate solar panel size for 220ah battery (in 6 steps)
It's important to consider real world factors when estimating the solar panel size for your 220ah battery.
In my experience, this is the most accurate way to calculate the solar panel size to charge your battery.
Steps
1. Calculate battery capacity in watt-hours by multiplying the battery amp-hours (ah) by battery voltage.
Let's suppose you have a 12v 220ah battery.
220ah Battery capacity in watt-hours = 220 × 12 = 2640 watt-hours
2. 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 lead acid battery.
Discharged Battery capacity in Wh = 2640 × 0.5 = 1320wh
3. Multiply the battery capacity after DoD by 1.15 for lead acid and 1.01 for a lithium battery. Battery charge efficiency rate - lithium: 99%; Lead-acid: 85% (source).
Power required to charge 220ah battery = 1320 × 1.15 = 1518wh
4. Divide the battery capacity value (after charge adding efficiency factor) by the desired number of charge peak sun hours.
Let's say you want to recharge your battery in 5 peak sun hours.
Solar power required in peak sun hour = 1518 ÷ 5 = 303 watts
5. Multiply the solar power required in peak sun hour by 1.2 if you're using a PWM charge controller and 1.02 for an MPPT charge controller. Charge controller efficiency, PWM: 80%; MPPT 98%.
Let's say you're using a PWM charge controller.
Solar power required after charge controller = 303 × 1.2 = 364 watts
6. Add 20% to the solar power required after controller covers up the solar panel's inefficiency.
Solar panel Required = 365 + 20% = 436 watts
Related post: Peak Sun Hours: Explanation, Importance, How To Calculate?
How Many Watt Solar Panel To Charge 220ah Battery?
Here's a chart about what size solar panel you need to charge a 12v 220ah lead acid and lithium (LiFePO4) battery in different peak sun hours.
| Charge Time | Battery Type | Required Solar Panel Size |
|---|---|---|
| 4 peak sun hours | Lead-acid | 450 watts |
| 5 peak sun hours | Lead-acid | 360 watts |
| 6 peak sun hours | Lead-acid | 300 watts |
| 10 peak sun hours | Lead-acid | 180 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 800 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 640 watts |
| 6 peak sun hours | Lithium (LiFePO4) | 530 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 320 watts |
Summary
- You need around 350 watt solar panel to charge a 12v 220ah Lead-acid battery from 50% depth of discharge in 5 peak sun hours.
- You need around 650 watt solar panels to charge a 12v 220ah lithium (LiFePO4) battery from 100% depth of discharge in 5 peak sun hours.
What Size Solar Panel To Charge 24v 220ah Battery?
Here's a chart about what size solar panel you need to charge a 24v 220ah lead acid and lithium (LiFePO4) battery in different peak sun hours.
| Charge Time | Battery Type | Required Solar Panel Size |
|---|---|---|
| 4 peak sun hours | Lead-acid | 910 watts |
| 5 peak sun hours | Lead-acid | 730 watts |
| 6 peak sun hours | Lead-acid | 610 watts |
| 10 peak sun hours | Lead-acid | 360 watts |
| 4 peak sun hours | Lithium (LiFePO4) | 1600 watts |
| 5 peak sun hours | Lithium (LiFePO4) | 1280 watts |
| 6 peak sun hours | Lithium (LiFePO4) | 1070 watts |
| 10 peak sun hours | Lithium (LiFePO4) | 640 watts |
Summary
- You need around 730 watts of solar panel to charge a 24v 220ah Lead-acid battery from 50% depth of discharge in 5 peak sun hours.
- You need around 1280 watts of solar panels to charge a 24v 220ah lithium (LiFePO4) battery from 100% depth of discharge in 5 peak sun hours.
220ah Battery: FAQs
a 12v 220ah means 2640 watts. To calculate battery capacity from ah to watts ( watts = battery Ah * Battery volts )
12v 220ah lead-acid battery will take about 10 peak sun hours to charge with a 180-watt solar panel from 50% depth of discharge
