Tuesday, April 9, 2019

Stages Of Wireless Power Enlightenment

As with all technologies, different people are at different ‘stages of enlightenment’ relating to wireless power. What are they?

1. I don’t know what wireless power is

Well, wireless power allows you to power or charge devices without wires or charging cables. It is more convenient than carrying a charging cord for you, or looking for a power outlet to plug it in.

To this group we say: Life’s better without wires.

2. I already have wireless power on my phone

If you have a newer phone, such as those from Samsung, Apple or Google, those phones support “magnetic induction” charging. This means that you can charge them by placing them on a charging mat. The user is still in the loop, needing to bring the phone to the charging pad, place and align the phone on it.

This is also called “contact charging” because the need for physical contact between the phone and the pad.

To this group we say: Long-range wireless is better.

3. I know of long-range wireless power companies

That’s good, The right long-range wireless power solution allows devices to charge without human intervention. This is immensely more convenient and useful that having to place the device on a charging pad, and certainly much better than connecting a charging or power cable.

It’s now time to ask for specs and inquire about performance. How much usable power can the technology deliver? At what distance? Is it certified as a safe consumer device? Can I buy an evaluation system? Can we see a public demo that is not behind closed doors? How large is the power transmitter?

When electric cars were first demonstrated, the fact that a car could run on a battery was news. Soon thereafter, consumer started asking the real questions such as asking for the driving range. This marked the transition from novelty to useful product.

To this group we say: Infra-red is the best long-range wireless technology.

4. Wi-Charge

We are glad to see you here. Indeed, infrared light is the best way (and perhaps only way) to deliver enough power to the most popular smart and mobile devices, to do it at a distance, and to do it while staying within consumer safety limits.

To this group we say: We look forward to working with you.

Thursday, April 4, 2019

Wireless-Power And The Self-Parking Office Chairs

A couple of years ago, Nissan had a wonderful demo project of their self-parking capability: they created a set of self-parking office chairs. They kept the office tidy by returning to their places when someone clapped next to them.

What does this have to do with wireless power?


These chairs are obviously wire-free. The motor on each chair consumes approximately 100 Watts. Let’s assume that it takes half a minute in a worst-case scenario for the chairs to move to place and let’s assume this happens five times a day.

Thus, the daily power consumption of each chair is 100 / 60 / 2 * 5 = 4.2 Watt Hour (WH). While 100 Watt sounds like a lot for long-range wireless charging, , 4.2 Watt hour can be provided if a system can deliver 1 Watt for just over 4 hours. And that’s in the worst-case scenario. This is well within the capabilities of the Wi-Charge system.

The morale of the story: always look at the average power consumption, not the peak power consumption when considering whether long-range wireless charging is a good fit for your application.

Thursday, March 21, 2019

Nature’s Wireless Power Delivery

Enormous amounts of energy are delivered wire-free in nature. It is really a source of life: wireless energy warms our atmosphere and water. Plants depend on wireless energy to grow.

How is the lion’s share of this energy delivered? Is it through huge magnetic fields? Pulsating radio frequency stars? Loud thunderstorms? No, it is delivered with light.

What allows most renewable energy to be harvested? Light again. Either directly, through solar panels, or indirectly, by causing temperature differences between regions, which then results in wind.

As a result, people, animals and plants have all evolved to exist with light. In fact, they all depend on it.

It would thus seem only natural that Wi-Charge chose light, and specifically infrared light, as the best method to deliver wireless power.

Monday, March 18, 2019

Measure Twice, Cut Once

What’s good for carpentry is also good for product design: have a well-defined set of requirements and plan your work before you start.

Here is a summary of the requirements we selected when we started our wireless power system design:

  • Safety. If it’s not safe, it’s not shipping. Safe enough for consumers to use, as defined by applicable government and regulatory agencies.
  • Power. Enough to charge a phone. Keeping a phone running ‘forever’ requires delivering about 500mW of power to the phone. Anything beyond that can recharge the battery. So we wanted to deliver at least 500 mW to the phone, but more if possible. We chose the phone because it’s the most obvious use case for long-range wireless power.
  • Distance. At a minimum, deliver energy – enough to charge a phone – at room-sized distances.
  • Small receiver. Small enough to comfortably embed into phones or other smart devices.
  • Small transmitter. Small enough to be inconspicuous in a home and an office environment.
  • Easy to integrate. No custom antennas or other major engineering efforts required from our customers.
  • Support multiple devices. Able to support “one-to-many” charging scenarios beyond the “one-to-one” one.
  • Plug-and-play. No configuration required. No alignment required. Just turn it on and it works.
  • Plays nicely with others. Does not impact existing communication networks, TV remote controls or anything else that is reasonably going on in a home or office environment.
  • Energy-efficient. Does not consume more than a small light bulb.
  • Ability to charge moving objects. While many use cases have to do with fairly static objects, we wanted to keep the option of charging a device while moving.

Tuesday, March 12, 2019

No Touching, Please

The latest Samsung Galaxy phones (and the Huawei Promate 20) now offer ‘reverse wireless charging’. This means that no only can these phones be charged by placing them right on a Qi charging pad, they can also serve as a charging pad for other devices. Thus, if your friend is out of battery and you feel generous, you can allow him to siphon some of your battery and charge his phone a little bit.

These phones use magnetic induction charging which sends energy over very short distances (for an overview of short- and long-range charging technologies, download an infographic from here). The problem with short-range charging is, as the name implies, that it is short-range. It requires someone to precisely align the charged device with the charging device. It involves a human in the loop and it pretty much takes both charging and charged devices out of use during the charging process.

What is needed is long-range wireless power transfer. One that does not require touching once device to another. One that does not require a human to be part of the charging process. One that can make phones and other devices appear to charge themselves without any human intervention.

Reverse short-range wireless charging is a nice feature, but the real disruption in charging will come once long-range wireless power technologies are embedded into consumer devices.

Wednesday, March 6, 2019

The Lab Experiment

Every week, we get dozens of requests for partnerships. Below is my favorite from this week. Names and locations have been redacted for privacy.

I’m from an animal research lab at ____. For experiments, the animal runs freely or performs cognitively challenging tasks as we study it’s natural behavior. Neural signals are recorded from various parts of the brain and wirelessly transmitted using a transmitter carried by the animal. The size and weight of the lithium ion battery used for the transmitter is restrictive and we were looking at ways to reduce battery size while still preserving battery run time. Your product for wirelessly charging the battery at a distance would be the perfect solution to this.

I guess this is the new meaning for the term “wireless mouse”

Wednesday, February 27, 2019

Reddit AMA Recap: Long-Range Wireless Power



Wi-Charge's Ori Mor and Yuval Boger recently hosted a reddit “Ask Me Anything” (AMA) session in the r/homeautomation subreddit. The AMA covered a number of topics around the wireless charging landscape, the pros and cons of long-range wireless charging and the different use cases that could benefit from such innovation.

You can find the highlights from the AMA below, or you can read the full thread on the subreddit here. If you still have questions that have not been answered in this AMA or on our FAQ, feel free to reach out to us here

How long until the Wi-Charge is available to the public?

We expect that the first consumer products incorporating Wi-Charge technology will be shipping to customers within the next year.

Is the 1 Watt per module still in the proof of concept stage?

There are numerous applications today in which 1W is plenty of power for smart home devices and smartphones. Consider a device with 4 AA batteries that you’re willing to replace every 6 months. This works out to approximately 1 mW of average power. Wi-Charge can deliver hundreds of more power continuously.

This means that, beyond not having to replace batteries, you can add features to devices that you could not before, such as adding a camera to a smart lock, having a cordless smart speaker and installing indoor security cameras with streaming video.

Requiring line of sight seems challenging in a typical household environment. Is the thought behind this that there would be many transmitters in strategic places around a home?
One could have multiple transmitters, just like there may be several Wi-Fi repeaters or multiple access points in a larger house. Imagine these transmitters as part of a light fixture, making it easy to install. Regarding the line of sight, this is the only way we are aware of to deliver meaningful power, at a distance, efficiently and within consumer safety limits.

What is the efficiency of the laser to the panel?

The efficiency is 100%, as all power leaving the transmitter reaches the receiver (panel) unit. Light can travel long distances without the beam becoming meaningfully wider. That’s why 100% of the beam can still hit a small receiver even at a distance.

What sizes are the current panels? Do you see the panels changing over time?

The current cells are not very large – they are only about the size of a thumb. We designed it to be small enough so that it can be easily integrated into a phone, home security sensor or another device.

How safe and reliable is Wi-Charge, especially when using such powerful lasers?

Our product is rated Class I, and we were approved worldwide for safety performance. Wi-Charge technology was developed under the constraint of being a class I product, which means “safe under all conditions.” We spent a lot of time and engineering to come up with a solution that would meet all safety regulations.

Can you deliver 1W continuously under class I?

Yes. This technology was tested and approved by the FDA and other internationally accredited safety labs. Keep in mind that when we say 1W, we are referring to 1W that is truly available for the client device.

Can the light energy from the panels reach any people or things?

Since almost 100% of the light energy reaches the panel, this means that 0% of the light reaches people, pets, plants or objects that do not wish to receive unintended energy. The panel itself is more efficient than a typical solar panel.

What has industry adoption been like?

Industry adoption has been outstanding. We receive over 100 incoming partnership requests each month, most likely because so many people realize that this is an important problem to solve. Several companies are evaluating and building prototypes using this technology, and some companies like Alarm.com and Schlage have even done public demos.

What are some use cases of this technology?

With this technology, we are able to charge a phone without a pad or wire, deliver power to home security devices without requiring battery replacements, make wireless light fixtures, have digital signage and point-of-sale products, deliver plenty of power to AR/VR devices so that they don’t need a battery pack, enable surround speakers and power smart locks and indoor security cameras. For more on this, please visit our applications section on our website and view our demo videos on YouTube.

How is charging mobile phones and powering wireless speakers without batteries possible using 1W?

The power level that you need to sustain a phone is approximately 0.5W – current phones have approximately a 10 WH battery and have an operating time of about 20 hours. Anytime you are delivering more than 0.5W, you are making a positive contribution to the battery. If the phone is on standby, it consumes less than 0.5W. A wireless speaker would likely have a rechargeable battery as well. This allows you to drive higher-power speakers, assuming they don’t operate 24 hours a day. For instance, if we have a 3W speaker that is used 5 hours a day, you need 15-Watt Hour. If you are providing 1 Watt of charging all day, you are delivering more than that number.

Today’s fast cable charging is necessary because you would want the phone to charge as quickly as possible, as you are giving up the use of your phone when it is charging. If you have ongoing charging throughout the day, charging at a lower wattage than the quick charge is also useful.

What would its role be in regard to home automation? Something like keeping motion detectors and contact sensors powered wirelessly?
You can eliminate battery replacements, install devices that previously needed to be wired without wires or create new devices that have the mobility of battery-operation but the power requirements of wired sensors. Additionally, you can also turn existing wired devices into wireless ones. For instance, at CES we showed how we turn an Amazon Echo or Google Home Mini smart speaker into wireless devices (see the bottom of this page).