How long does it take to charge 20000mah power bank for the first time?

Firstly, I recommend flipping through the user manual before you use your power bank. And if it doesn't have or if its not easily understandable, then perhaps you shouldn't buy it. That’s an indication it could be a fake.

I always worry when people talk about 20000mah or higher capacity power banks (pb). This is because from personal experiences they tend to be fake products, especially portable power banks. Some of the reasons are indicated below based on my experience of HetoGrow solar power bank chargers.

To answer the question,

1. The time it takes to charge a power bank depends on  many factors chiefly input current - voltage/Amp, and charging cable/source. I normally recommend a USB 2.0 cable. There are other factors some of which I’ll try to explain below.
2. Since you say its “for the first time” I’ll assume its brand new, in which case, like any new phone, there should be some power in it already. Therefore an overnight charge of about 6 hours should be sufficient. A specific answer will require some technical info such as summarised below.

Some power bank technical info to consider

1. Most mobile devices like power banks are normally designed to charge gadgets at 5 volts at a given amp. For instance, a 10000 mah power bank could receive and give charge of say, 1 Amp at 5v for 10 hours, or 2 Amps for 5 hours. You’ll need to know what these are for your power bank and the gadgets you want to use it for. For 20000 mah, you can therefore expect between 20 hours and 10 hours for 1 and 2Amps respectively at 5 volts.
2. In summary, volts/Amp basically indicate energy capacity and rate of flow of electric charge i.e., current. The higher they are the faster the charge. For instance, a standard car battery is a good example of a power bank with 12 to 15 volts and 45Ah to 75Ah (circa 45000mAh to 75000mAh). You may have noticed that when you plug your phone into a car that is running, it charges up quite quickly. This is because of the higher capacity to charge and little lost energy due to closeness to the source. Electric charge is displaced/lost over long cables.
3. There are several other factors to consider including temperature, discharge rate, brand/quality of production, whether or not the mAh rating of your power bank is real or fake, etc. I recommend you have a look at “What is a Power Bank?” and “How To Detect a Fake Solar Power Bank” sections of the HetoGrow Quality Assurance page. It is an excellent effort to simplify technical and basic info about power banks so that anyone can understand.

Hope this has been helpful.

Dave Ebi is a Most Viewed power bank writer on Quora. Join us on Facebook, Twitter, Instagram, G+ or LinkedIn

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