Best Tips for Faster Solar Phone Charging

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There is no shortage of articles saying that solar is the future of energy, and it’s true. Solar power is free, renewable, clean and efficient. Cost is going down too which is great for consumers. But the biggest issue here is the slow charging time of solar phone chargers, which can take several hours or even half a day. That can be really frustrating for many.

Use short cables, charge outside and position the charger so it faces the sun. The charging cable also affects charging time so make sure you only use short, thick cables.

And yes, solar phone chargers, despite the name, can charge tablets and other devices. There are also fast charging solar phone chargers so you may want to check those out too. For now, here are the best tips for faster solar charging

1. Charge with Short Cables

This might seem unrelated to charging, but using shorter cables speeds up phone charge times. This won’t have any positive influence on solar panel charge times, but there is an effect when you charge devices.

Here’s why: cables transmit the energy from the solar panel to the charger to your device. The longer the cable, the more energy is wasted during the transfer. The shorter the cable, the more efficient the energy transfer and the faster it gets to your device.

Get the shortest cable you can use. Of course you want to make sure the cable length is sufficient for charging, but get the shortest one possible. Before you go hiking, test the cable if it’s the right length or if you can use a shorter one. Try comparing the charge time between a short and long cable and you will notice the difference.

2. Use Rigid Solar Panels for Charging

You can use any type of solar panel for charging phones, but efficiency will vary. Rigid solar panels can charge devices twice as fast as thin film (flexible) solar panels. Thin film is cheaper and flexible, but the trade off is less efficient energy conversion. You may have to buy two flexible solar panels to get the same charge speed as a single rigid panel.

Flexible solar panels do have one advantage, you can position it on uneven surfaces. Rigid panels have to bet set on flat surfaces to work, which can be difficult if you’re in the woods camping. If you go into rugged trails, it might be worth sacrificing the speed (or buying two sets) to ensure the panels work.

Solar panels are either monocrystalline or polycrystalline. Monocrystalline is more efficient in converting the sun’s energy into electrical power. However, the difference it makes in charging time is not enough to justify its higher cost. For residential or RV solar systems, it makes sense to use polycrystalline panels, but not for phone charging devices. Our recommendation is the Blavor Solar Power Bank as it can charge any mobile device.

3. Proper Solar Cell Position

Solar charging speed depends on the solar cells’ exposure to the sun. Direct exposure to the sun means faster charging speed. It’s so easy to solar charge a device we sometimes take it for granted. Just set down the panel, plug the phone into the charger and let it work.

But that is not enough. You have to position the solar panel so the cells directly face the sun. Failure to do this slows charging time by more than half. If you move the solar panels while charging, it will affect charge times too. That’s why charging while walking isn’t so effective. One moment the cells face the sun, the next you’re under some trees. The best time to solar charge a phone is when you’re resting.

We like solar chargers because it frees us from the constraints of electrical power. However we might not be maximizing its potential. Remember, the sun is your charger’s best friend. When the sun is out and bearing down on you, take a break and set the solar panels underneath the sun’s glare.

4. Charge Outside

Some solar chargers work indoors, i.e. you can charge devices with indoor lighting. But it’s too slow to be practical. Charge outdoors whenever possible. As mentioned in the previous tip, placing the solar panels under direct sunlight is key. But you need to be careful because solar efficiency goes down if it is too hot.

It sounds confusing but it’s true. Solar power systems convert the sun’s energy into electrical power. As the temperature starts rising, the solar panel heats up, the current output goes up, and the voltage reduction drops. The end result is slower charging speed.

Check the specs of your solar charger to determine the ideal temperature range. Note that the drop in voltage isn’t really that significant unless it’s really hot in your area. If it is too hot, wait for the temperature to cool down a bit or look for a well ventilated open area.

Do not charge your phone from your RV’s window. The window obstructs the interaction of the panel and the sun and reduces charge speed. Just wait for warm – not too hot – temperature outside before starting a charge.

5. Solar Panel Size Matters

The panel surface area determines how much sunlight can be stored and placed in the battery. The larger the solar panel, the more energy is collected and the faster the charge. Smaller solar chargers are slower, but they’re lighter to carry and store. You can check out the Shenzhen Portable Solar Charger as i offers nice balance between size and weight.

If charging speed is the priority, buy the largest solar phone charger you can carry. The extra weight will be worth it when you start charging. iI you want to travel light and don’t mind long charging times, get a light solar charger. There are many types of solar phone chargers, but the most basic consists of just solar panels and a cable to plug in your phone.

Solar chargers may come in various forms, but the basic function remains the same. Just like the large residential solar panels, the panel watt size and battery capacity (if included) makes a lot of difference. Before you go on your next outdoor adventure, determine which is important, speed or weight.

What Type of Solar Charger Should You Buy?

There are four basic options:

  • Basic solar chargers: these consist of panels only
  • Integrated solar battery chargers: consists of a battery pack and solar panels
  • Independent solar battery chargers: the storage battery is separate from the solar panel
  • All in one portable solar chargers: comes with solar panels, battery storage and other features like a flashlight, USB ports, multiple charging etc.

No single type is better than the other. It depends on what kind of a camper / backpacker you are. Take into consideration the surface area and amount of sunlight available as they influence charge speeds more than any other factor.

Solar charger output capacity are measured in watts. The higher the wattage, the greater the charger’s capacity and the faster it can charge. Again it will depend on the prevailing conditions in the area and how depleted your device is.

Two Ways to Solar Charge Your Phone

There are many types of solar charges that you can buy, but charging is done basically two ways

The solar panel is connected to a rechargeable battery, which in turn connects to your device. It is the battery that charges your phone or other device, not the solar panel directly.

This means one thing: solar power is stored in the battery for later use. Meaning you can charge your phone at night. Just charge the battery during the day and you’ll be able to charge your phone every night. Batteries can be NiMHs, AA NiCADS or lithium ion.

Lithium ion offers the best performance, but it is going to cost more than regular batteries. AA / AAA batteries are removable. You can also use AA batteries for other devices if necessary. Of course most phones use lithium ion nowadays.

The power and capacity of the battery determines how efficient the charge can be. The battery also determines how often you can recharge your device before requiring a solar panel recharge. Most if not all chargers don’t come with a blocking diode to prevent power drain from the device into the battery. Unplug the device from the charger if the battery is almost or already empty.

Solar phone chargers have connectors for use with your phone. However there is no standard connector for mobile devices, so connectivity issues can arise. The good news is many are now moving towards USB, so a standard may be forthcoming. Note: integrated battery pack chargers come with the required cables

The solar panels charge your phone directly. There is no battery pack. It is just your phone (or any mobile device) hooked up to the solar panel and charged under the sun.

Charging is done with a 12V cigarette lighter socket. Thin film (flexible) solar panels usually have a cigarette lighter socket attachment where a cigarette lighter is plugged. The 12V cigarette lighter plug is a separate purchase, and you have to make sure the lighter is compatible with your phone.

The benefit of these chargers is flexibility. You don’t have to carry a battery pack, important if you want to hike / travel light. There are a few things you need to be aware of though.

  • Direct phone charging from solar panels is 100% dependent on the sun. If it’s cloudy the charge could drop drastically. Unlike integrated battery chargers, you cannot charge during the evening. or anytime it is overcast. If the cloud passes and the sun’s out again, you have to disconnect and reconnect your phone to resume charging.
  • Not all iPhones are compatible with 12V sockets. Please refer to your iPhone documentation for information on soar charging options. This doesn’t seem to be an issue with Android devices though.
  • A growing number of solar panel only chargers now come with USB ports. As mentioned above USB ports are increasingly popular so don’t be surprised if yours came with these ports.
  • Some phones do not accept low current trickle charge. Some even work only with specific power rates such as 120mAh. Refer to your phone’s documentation for more information.

So which is better, charge via battery or charge directly via solar panels? Although direct solar panel charges work, we recommend charging your device with a battery than directly from the solar panels.

The biggest issue with direct solar panel charging is the lack of circuitry regulation. There is nothing that regulates the flow of current in your device. Think of your laptop or any other appliance. You have a voltage regulator to monitor the current and ensure electricity flows at safe, optimum levels. Some solar panel only chargers don’t offer that kind of protection, which could damage your device.

It’s another story if your solar panel charger has protective measures built in. In that case you can charge with confidence. But there is still the issue of being completely dependent on the weather and inability to charge at night. For practical purposes a solar charger with integrated battery pack is more ideal.

Check the Battery Pack Specifications

If you opt for an integrated storage battery charger, keep an eye on the battery specs. The solar panel is important, but it is the battery that will tell you how efficient the charger will be.

  • mAh /aH (milliAmp hours): Amp hours tell you how many recharges are left. mAh to ah conversion is simple, 1100 mAh=1.1 aH and so on.
  • Energy transfer is never 100% efficient.. A 2000 mAh battery pack cannot charge your 1000 mAh two times because there will always be some losses. Your battery pack needs to be higher than 2000 mAh if you want to charge your device twice.
  • The battery pack must have sufficient output voltage and storage capacity to transfer energy into your device. Check your device’s capacity for information.
  • The charger’s voltage output has to be the same as your device’s input battery voltage requirement.
  • Even the most basic solar charger can power up music players and mobile phones. But they usually don’t have enough to charge a laptop.
  • A 5V output rating is required for devices chargeable with USB cables. Laptops and other devices that need a DC input require a higher output rating, around 12V to 24V.

Lithium ion is the best option. It is the most often used in solar chargers, mobile phones and other electronic devices. It is lightweight, safe, efficient and dependable. Lithium polymer is another type of lithium battery that also works well with mobile devices and electronics.

Lead acid provides the highest output, but they are heavy and could corrode. NiMH batteries re used in AAA and AA batteries. They’re great for lamps, GPS, flashlights and portable radios. These are your regular batteries that you replace instead of recharging.


If you look up tips for faster solar charging, you’re not going to find a lot of results because most don’t know how. Many just accept the slow charges and learn to live with it. With the tips above, we have shown you don’t have to put up with it, as you can speed up those charges.