Solar Charger vs Power Bank - Which is Best?

  • Aug 25th 2018

There are three categories of portable battery chargers: Solar panel chargers, power banks, and hybrid solar/battery chargers. Both solar chargers and power banks serve their purpose, but we do not think that hybrid chargers are worth spending money on. If you buy a hybrid solar/battery charger the chances are you will just be disappointed when you notice just how slow they are at charging. Looking at solar charger vs power bank and which one is the best for you it all depends on your specific use case. In this article, we will list all the pros and cons for each type and also give advice about what to consider when shopping for a quality charger.

Index

  1. Solar panel charger pros
  2. Solar panel charger cons
  3. How many Watts do a solar charger need to charge my phone fast?
  4. Power bank pros
  5. Power bank cons
  6. How many charges will I get out of a power bank?
  7. Hybrid solar/battery charger pros
  8. Hybrid solar/battery charger cons
  9. Conclusion
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Solar Panel Charger Pros

  • Free electricity - solar panel chargers provides free power from the sun. Free electricity is great and as long as your solar panel does not break you can harvest the sun’s energy for as long as you want.
  • An unlimited number of charges - unlike a power bank the charges does not run out and have to be recharged through an outlet. The solar charger will just keep producing electricity.
  • Eco-friendly - the electricity from solar power is renewable, as long as the sun shines you can get more power from your panels. There is no pollution or other negative effects on the environment when using solar power.

Solar Panel Charger Cons

  • Bulky - to have a satisfactory effect the panels need to be pretty large. Do not bother with the small 2 to 5 Watt panels you will just be disappointed that they are too slow to charge your phone. We suggest a foldable solar panel which is less bulky and that have handles for easy carry.
  • Needs the sun - You will not be able to charge during the night and many cheaper variants will not be able to charge on cloudy days either. Again, do not bother with the smallest or the cheapest solar chargers, get a quality charger that works even when the sky is cloudy. Many devices are sensitive to fluctuations in the current when charging. iPhones, for example, might stop charging completely if the input current varies too much. This should not be a problem with high-quality solar panel chargers since they often have some sort of charge controller built in.

How many Watts do a solar charger need to charge my phone fast?

In theory 10 Watt since you want 5 Volts and 2 Ampere to quickly charge a phone or tablet. In reality, there is always some loss in efficiency due to heat dissipation and resistance in the electronics. The important thing to look for to see if the solar charger is fast is that it can output 5 Volts at 2 Ampere. High-quality solar panel chargers marked 15 Watt or higher should be able to accomplish this. The TuffGear 15W is a good example of a solar charger that will charge a phone fast and still is lightweight and compact.

How long does it take to charge my phone with a solar panel charger?

A typical solar panel marked with 5 Volts 2 Ampere output would take 1 hour to charge an iPhone 7 (2 000 mAh). A panel labeled 5 Volts 1 Ampere would take 2 hours.

Power Bank Pros

  • Reliable - does not require sunlight or anything else to work. As long as there is charge left in the power bank, you can charge your device.
  • Compact - power banks are lightweight and small. Be careful not to get tricked by the super compact power banks that claim high capacity. With the current technology, batteries still have a limit on how small they can get.

Power Bank Cons

  • A limited number of charges - A fully charged power bank with high capacity (around 10 000 mAh) can typically charge your phone 3-5 times before it runs out.
  • Decay over time - All power banks lose charge even if they are not being used. Some lose more than others. This is not something that would matter if you if you look at a scope of just a few weeks. The lost charge in that time period is too small to notice. The very best power banks can actually keep up to 80% of their charge even after 3 years.

How long does it take to charge a phone using a power bank?

A typical power bank with an output of 5 Volts 2 Ampere would take 1 hour to charge an iPhone 7 (2 000 mAh). A power bank marked 5 Volts 1 Ampere would take 2 hours.

How many charges will I get out of a power bank?

One might think that a 20 000 mAh battery will fully charge a 2 000mAh phone 10 times. This is not the case since the charging is not 100% effective. The lower Ampere the power bank use to charge your device the more energy is lost. Charging at 1 Ampere typical gives a 10% loss. On top of that, the fact that many manufacturers mark their power banks in a deceiving way makes it even more far from the correct number. Many power banks are not marked with the capacity at 5 Volt (which is what your phone or tablet need) instead they label the battery's capacity at 3.7 Volt. This only gives 74% of the capacity when charging at 5 Volt. So a 20 000 mAh power bank that is labeled in this way would only give 6.6 full charges and not 10.

Hybrid Solar/Battery Charger Pros

  • All in one solution - you get all the features of both a power bank and a solar charger in one product. Unfortunately, the solar charger component is so lackluster and maybe this can not be considered a pro.

    Update: It seems that hybrid charger manufacturers have started to see that people are not interested in these kinds of products and have now started building models that have much larger solar panels. For example the the ADDTOP 24000 mAh Hybrid charger now have 3 panels that can be unfolded to a relatively large size. They claim that it should be able to charge at 0.75 Ampere which would bring it a little closer to power banks and solar chargers. We think this is a step in the right direction but it is also essentially just a power bank combined with a solar charger. It can still be a good investment if you do not already have either a solar charger or a power bank.

Hybrid Solar/Battery Charger Cons

  • Efficiency - the size of the solar panel on a hybrid charger is often too small and capacity over 2 to 3 Watt is rare. This is much to small to be of any real use except giving a little bit of support charge to the internal battery. Depending on the capacity of the built in battery you will have to leave the hybrid charger in the sun for days to fully recharge. For example the GiDgat Solar Charger Power Bank is one of the best in this category but it can only charge at 0.1 Ampere under optimal conditions, which is 20 times slower than a solar charger or power bank
  • Size - hybrid chargers are oversized compared to power banks but still much too small to be efficient solar chargers.
  • Affordability - hybrid chargers are more expensive than power banks with similar specifications.
  • A limited number of charges - A fully charged hybrid power bank with high capacity (around 10 000 mAh) can typically charge your phone 3-5 times before it runs out. The small charge boost it gets from the solar cells is often negligible.

Conclusion

Hybrid chargers have too small and weak solar panels to work satisfactory and should be treated as novelty power banks. The very best option is to get both a solar charger and a power bank. This combination will provide you with free portable electricity that does not run out. If you can only afford one of the two it all depends on your use case. If you are satisfied to have a limited number of full charges for your phone, a power bank is the best option because of it's compact size and portability. But if you plan on going off the grid for longer periods, a high-quality solar panel charger is the way to go.

If you have decided which portable charger is the best for you we offer more in-depth articles on both Power Banks and Solar Chargers to help you make the best pick possible.