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[Tested In Japan] How Long Does Pocket WiFi Battery Really Last?

So you are going on vacation to Japan and you want to rent a Pocket WiFi device. One of the main questions on your mind may be, how long will the battery last me? This is one of those questions that you may have heard horror stories about from friends who took a trip to Japan and rented a Pocket WiFi device from one of the major kiosks at the airport, like this girl below.

Her problem was that the battery only lasted her 3 hours when left on. However, how she was using her device along with a couple of other factors, may have played a role in how long her Pocket WiFi battery lasted her.

My goal is to demonstrate, by testing it out, that the way you use your Pocket WiFi device has a decisive impact on the amount of time your battery will last you. I also want to get everyone on the same page when it comes to the truth about Pocket WiFi battery life.

What You Can Expect from Pocket WiFi Battery

We can't make any definite guarantees about how long a Pocket WiFi's battery will last any particular individual because the truth of the matter is; your Pocket WiFi battery life is directly correlated to the amount of data you consume. This is essential to understand if you want to get the most out of your battery. For example, if you stream Netflix and YouTube videos for hours on end then yes, your battery will drain much faster and you will need to recharge sooner. But if you're just using the device for things like map applications, internet browsing, and SNS applications, you should have no problem making your battery last longer.

The batteries in these devices all use lithium-ion batteries, the same battery you can find in most smartphones, tablets, and laptops. These are quality batteries but are also subject to deterioration in quality and energy retention over time. These are also the same batteries that every company in Japan that offers pocket WiFi rentals are using. This means that regardless of the company you rent from, the battery life will generally be the same.

Okay now that you know a little about these Pocket WiFi batteries, let's get into the actual test.

Test Breakdown

The test was simple. It consisted of taking the fully charged WiFi unit with me at the beginning of the day and timing how long it took for the battery to die or reach critical levels.

Test Results

I took a 4G Pocket WiFi device (model: 501HW) with me in the morning and used it throughout the day. It's got a battery of 3,000mAh (11.4Wh). Charging the device fully at night took me around 4 hours. I used it to surf the internet on my smartphone, and even streamed Spotify with it at night. The device lasted me from when it was fully charged at 9 am, until dying completely at around 7 PM when I switched to the power bank which eConnect Japan offers free with every pocket WiFi rental. This length was quite impressive considering some pretty heavy usage as well as being connected to 4G network for most of the day.


Lasted for 10 hours, the majority of time on 4G, until the battery died completely. I used the Pocket WiFi unit a decent amount, but there were long gaps throughout the day where I didn't use it either. This may have helped the battery last so long.

This image shows the Pocket WiFi screen after 7 hours of use. You can see that the battery bar in the upper right-hand corner is down substantially, but it still reads green. This means that the device still has some juice left in it.

The next photo below shows the Pocket WiFi after 10 hours of use. When this message appears on your screen and you can see that the battery icon has turned an orange-like color, it means that your battery is on its final legs. The device will shut off shortly after this.  


To summarize, battery life depends on usage. The best way to ensure your battery lasts as long as possible is to use your Pocket WiFi economically or to bring a power bank with you. If you know you will need WiFi for a good portion of the day, then maybe don't stream Netflix or YouTube too much. Also, you can't have unrealistic expectations for your battery performance. If your battery is lasting you for the majority of the day, that is already pretty good performance-wise. Our recommendation is that you treat the Pocket WiFi device just like your smartphone, charge it once at night while you're sleeping, and you can expect it to last you for a good portion of the day.

To be a reliable mobile internet provider in Japan, we make sure that the batteries in our devices have been changed once every 1 to 2 years in order to ensure you have a working lithium-ion battery that has not deteriorated much. This is actually something that eConnect Japan does that cannot be said for many of the other companies offering Pocket WiFi devices throughout Japan. But there is no reason to worry about your device's battery dying anyway because we provide you with a free power bank should you need to use your Pocket WiFi with more frequency.

In any case, the point we would like to hit home today is that no matter which company's device you choose they are all the same, but armed with this knowledge, you should be able to make your battery last longer!

Take it easy and enjoy your travels!