How Long Do Solar Chargers Take to Charge a Phone?

A typical solar panel on a portable charger produces around 5V at 1A (5W) under ideal conditions. A phone battery holds about 3000mAh, requiring roughly 15Wh of energy. With a 5W panel, that's 3 hours of perfect sunlight, but real-world efficiency drops to 50–70%, so expect 4–6 hours for a single charge.

For a power bank like the GOODaaa 24000mAh, you'd need to charge the bank itself first. At 5W, that's 24000mAh * 3.7V = 88.8Wh, divided by 5W = 17.8 hours, but with losses, it's closer to 20–25 hours. Then the bank charges your phone in about 2–3 hours via its 3A output.

Using the SOARAISE 48000mAh power bank as an example: it has a 3A output, so it can charge a typical phone (3000mAh) in about 1 hour when fully charged. But to charge the bank itself via solar, you'd need 48000mAh * 3.7V = 177.6Wh. At 5W, that's 35.5 hours ideal, but with efficiency losses, expect 40+ hours.

The GOODaaa 24000mAh is lighter and faster: 88.8Wh / 5W = 17.8 hours ideal, but realistically 20–25 hours. If you're charging your phone directly from the solar panel, you'll get about 5W, meaning a full phone charge takes 4–6 hours of direct sun.

The biggest factor is sunlight intensity. A panel rated at 5W only hits that under full sun at noon. Cloudy days reduce output by 50–90%. Also, the angle of the panel matters: it should be perpendicular to the sun's rays for maximum efficiency.

Temperature also affects performance. Solar panels lose efficiency when hot, so on a scorching day, output drops. Battery capacity is another factor: a 48000mAh bank takes twice as long to charge as a 24000mAh one, all else equal.

First, always charge a power bank first, then use it to charge your phone. This avoids intermittent solar output. Second, position the panel at the optimal angle and rotate it every hour to track the sun.

Third, keep the panel cool by placing it on a reflective surface or using a small fan. Fourth, use a high-quality cable with low resistance. Finally, avoid charging in extreme heat or cold, which reduces battery efficiency.

• Use a power bank as a buffer
• Angle the panel perpendicular to the sun
• Keep the panel cool
• Use short, thick cables
• Charge during peak sun hours (10am–4pm)

The GOODaaa Solar Power Bank 24000mAh ($34.98, 4.4★, 2446 reviews) is a solid choice for most users. It's lighter (420g) and charges faster due to its smaller capacity. It has 4 built-in cables and a 3A output, so it can charge a phone in about 2–3 hours when pre-charged.

The SOARAISE Solar Power Bank 48000mAh ($59.99, 4.2★, 6109 reviews) offers double the capacity, making it ideal for multi-day trips. However, it takes longer to solar-charge itself (40+ hours). Both have lithium polymer batteries and 3A output, so phone charging speed is similar.