Initial Thoughts

My first observation when I opened the Feynman promotional power bank, was that Feynman Promotional Power Bankit was large. It is nearly 8” x 4”! Then I realized that this feels like a well built, quality piece. Both sides are covered in a rubberized material, giving it a great feel.

There are six ports on the Feynman, three input and three output ports. The three input ports are: Micro USB, USB – Type C, and Apple lightning, meaning that you can charge the Feynman with any one of these three cables. There are two 2A outputs and one 1A output, for charging multiple devices at the same time.  I really like that each port is labeled on the bottom of the power bank so that the labeling does not distract from your logo which is printed on the top.

Charging Time

Once I had finished jotting down my initial thoughts on the Feynman, I plugged it in for the first time to get it fully charged.  As I first plugged it in, two of the four lights came on and were solid, while a third light began flashing. Five hours and five minutes later the fourth light stopped flashing and all four were solid, indicating that the power bank was fully charged. After it was discharged, it took roughly eleven hours to recharge to capacity.

Phone Charging

From a full charge the Feynman is able to charge my 2,600 mAh Samsung Galaxy S4 an average of 7.25 times before it is out of juice.  Charging the phone to 95% took just under 1.5 hours.  Additionally, I charged it only partially, several times. For example, in forty five minutes it charged my phone from seven percent to sixty seven percent. Another time, it only took one hour to bring my phone from a thirty percent charge to ninety seven percent.

It can also charge tablets. As with phones, the amount of charges you can get from it depends on your tablet. (If you have the new iPad Pro 10.5”, for example, the Feynman will be able to charge its 8,100 mAh battery more than two full times.)

UL Rating

The lithium ion battery in the Feynman has passed the UL standards for batteries.  Being UL rated is always good.  It indicates that a non-interested third party has tested the product to meet certain safety requirements.

LED Lights

There are four lights which show the charge level of the power bank. They light up when the power bank is either being charged or when it is charging a device. Additionally, there is a button next to the lights which will turn on these indicator lights when not in use so you can make a quick assessment of about how much capacity remains. Each light represents one quarter of the Feynman’s battery life.

Personally, I am not a huge fan of these indicator lights on such a high capacity power bank. Since each light represents 25% capacity, if two lights are on, the Feynman has anywhere from 25%-49% capacity remaining which represents 5000-9999 mAh.  That is really a wide range of capacity. It is very general.  I would prefer a digital display (as on the Mega Millikan) or more indicator lights but they didn’t consult me when designing this power bank.

Promotional Value

Promotionally, this is a great option.  There is a nice large 4” x 2” imprint area on the Feynman branded power bank.  A large imprint area means large impact and that it can be easily read from a distance.   And don’t forget, the Feynman can be upgraded to include a full color imprint for an even greater effect.


This is not a power bank which you keep in your pocket to charge your phone while you are jogging. It is a power bank which you bring on a weeklong hiking trip to keep your GPS tracker and phone charged. Others might use it in their office if their surge protector has no available outlets left and they go through their phone battery daily. Or if you are constantly using your phone or tablet and are on the move a good chunk of the day, you would definitely appreciate its features.  It is a well built, quality power bank.

Fun Fact

In 1979, Richard Feynman, this power bank’s namesake was named “The Smartest Man In The World” by Omni Magazine. According to, a website dedicated to this American physicist who worked on The Manhattan Project, upon hearing this, his mother said “Our Richie? The world’s smartest man? G-d help us!”.

Do NOT follow this link or you will be banned from the site!