How Long Does a 10000MAH Power Bank Last?

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Portable battery chargers or power banks are indispensable for anyone who has a mobile device. Whether it is solar powered or electric, it is something most of us cannot do without. But how long can a 10000mah battery last? How many times can you use on your phone? Is a solar power bank slower ore more efficient?

A 10,000mah power bank is going to last 10 hours on a device that uses 1,000ma an hour. If the device uses 500ma, the power bank is good for about two hours.

Power Bank Capacity Explained

The math is straightforward. Most smartphones have a 2000mah battery, so a 10000mah power bank like the Miady Dual Portable Charger should be able to charge it five times. But due to several factors (which we will get to shortly), a power bank only has about 66% or two-thirds of its stated capacity. That is why you can only charge 3-4 times maximum depending on the phone’s discharge level.

The reason for this is the difference in voltage. Most mobile devices charge at 5 volts but power banks are at 3.7V. Instead of mah, it is better to use mwh (watt hour) because it calculates all the energy in the power bank. It also doesn’t use voltage in its calculations so it’s more precise.

A 3.7V 10000mah battery has 37000 mwh (10000 x 3.7 = 37000) .

But because mobile devices use 5V, you have to divide the watt hours by 5V.

37000mah / 5V = 7400mah

Plus you have to account for 10% energy loss in the cable wires. 10% energy loss means 90% efficiency.

7400mah x .90 = 6660mah

This is why power banks only have 66% usable mah. This is a general estimate, as the charging performance will vary from device to device. But you can use the two thirds capacity rule as a guideline if you want an idea of how much you can get from a power bank.

This conversion formula is applicable to other power bank capacities. You just replace 10000mah with another power bank capacity. Since chargers and mobile phones generally have the same voltage, you can use the same steps. And if the voltage is different for your device, use that figure instead of 5V.

How Many Times Can a 10000mah Power Bank Charge an iPhone?

Power banks do not have the capacity of powerful solar panels that run heaters, but for iPhones and tablets, it is more than enough. The following table assumes a 0-% conversion rate efficiency. While this is for iPhones, you can expect similar results for Android powered phones.

The following assumes each iPhone is fully discharged each time and is topped of at 80-85%. You will be able to do more chargers if you recharge before the phone battery drops to 0%. The charging frequency may be lower for tablets depending on how depleted it is.

iPhone Release VersionNumber of Charges
7 Plus2.2
6 2.3
6 Plus 2.2

How Long Does a 10000mah Battery Take to Charge a Phone?

A standard or solar power bank can charge an iPhone from 0% to 80% in 35 minutes or less. But it could take hours more depending on the following factors.

Mobile phones today have support for USB-C PD or QuickCharge 3.0, technologies that provide rapid charging. And by rapid we mean fast. Back in the days you had to wait hours or days to recharge a mobile phone. Now if your solar power bank has QuickCharge or USB-C PD support, it takes minutes.

Charging on a USB-C PD such as the Anker PowerCore Essential takes your phone from 0-50% in half an hour. With a QuickCharge your phone can go from 0%-80% in 35 minutes or so. The disadvantage is a lot of volts and current are discarded, reducing the power bank life by up to 20%. But speed is of the essence, then these technologies make all the difference.

How Much Phone Battery Charge is Left?

That figure above assumes the phone is fully discharged and topped off at 80%, because charging to 100% isn’t not advisable. 35-30 minutes is fast, but it will be even faster if you recharge early.

If it takes a 10000mah QuickCharge power bank 35 minutes to recharge from 0-80%, what more if you recharge at 30%-40? Expect the charge time to be 15 minutes or less. The general rule with lead acid solar batteries is to recharge tat 50%. You don’t have to do that with an iPhone, but recharging at 30% will make charging even quicker.

Power banks have multiple charge options like solar, USB QuickCharge, USB-C PD, AC outlet etc. Which one you use for your 10000mah charger determines it speed. Solar is the slowest, followed by the regular ports. QuickCharge and USB-C PD are very fast as well as AC outlets.

How to Make a 10000mah Power Bank Last Longer

Power banks are usually warranted to last 3-5 years, but it will last longer if you take care of it. Here are some suggestions to make your power bank last longer and be more efficient.

Use Solar Power Whenever Possible. Portable solar chargers are faster now, and it can prolong the life of your power bank. Using the sun’s energy conserves battery and reduces wear and tear. Solar power does not require any maintenance either. Just let the power bank charge until your device is full. Nowadays you only have to wait a few hours or minutes to get a full charge.

Buy High Quality Power Banks. You get what you pay for, and that is true for power banks too. Quality battery chargers will cost more but last longer. They are built for long term use and have a long warranty like solar panels. The conversion rate is at 90% or even 05%, allowing you to charge faster.

The extra amount you pay for a good power bank is worth it. It is is cheaper to buy a good power bank than settle for a cheap charger, only to have it break down while you’re using it. Not only is it inconvenient, but you have to pay extra to buy a good charger.

Use Short Cables to Charge Phones. Using a short cable leads to faster solar charging, and this applies to any 10000mah charger. These cables are specially designed for device charging. They have unique contacts that reduce energy loss and it is more convenient to carry a short cable during camping than a long one.

Use QuickCharge Ports Only if Necessary. QuickCharge USB ports are very fast, but it also wears out power banks faster. If you are not in a rush, use the regular charge port. It will not be as quick but it is going to preserve the charger and not waste any current or volt.

Use the Power Bank Only as Directed. Sounds obvious, but a lot of chargers get damaged due to improper handling and usage. Follow the directions for use and do not use the charger on any device that it is not meant for. Do not drop or bump the power bank and store it properly when it is not being used.

Tips and Reminders

Power banks are not created equally and neither are mobile phones. Whether it is an iPhone or Android, there are several factors that determine how fast or slow charging from a 10000mah battery will be.

Even the most powerful inverters are not 100% efficient, and the same is true for phone batteries and power banks. The best efficient rate is in around 95%, but most are at 90%. The higher the efficiency rating, the faster the charge. The opposite is true. Older power banks waste a lot of energy and took way more time recharge a battery. New technologies have enhanced charge time, but it works only if your phone supports it.

Have you notice how your phone no longer charges as fast as it used to? And that it loses power more quickly? It is a sign of degradation, which happens to all batteries eventually. No matter what kind of power bank you have, it won’t change the performance of a deteriorating phone battery. The only solution is to replace the old battery with a new one.


10000mah battery chargers used to be the top of the line, but more powerful power banks are now available. But even if you have a 10000mah charger, expect to get a solid performance from it. This is true whether it is solar powered or it uses other means of charging.