Using battery power for small LCD displays is a smart idea – It simplified the installation to be quick and hassle-free and it sets up new areas of the store for powerful digital promotions. However, taking batteries with screens designed and configured only for use with AC Mains power can bring unsatisfying results, with limited battery life and sluggish performance. To achieve startlingly effective performance from your battery-powered promotions, AOK Displays has developed “low-power play” solution. Low-Power Play combines the latest in power management technologies with the use of interactive features to drive displays that deliver effective content where and when you need it.

Conserving Power

The aim for most battery-driven promotions is to balance effectiveness with battery life. This is where Low-Power Play becomes highly effective. It employs the latest in intelligent power management technologies to maximize availability while conserving power. Promotions can use batteries to power content running continually, but this isn’t the norm as batteries powering continuous playback need renewing very frequently. Instead, Most successful battery driven deployments use some form of sensor or interactivity.

Using video-triggering Interactivity

Playing content when your customers are not present to view is a waste of battery power. Low-power Play uses interactive video triggers such as PIR motion sensor, buttons and touchscreen to control the delivery of content. Most common is for a display to use an ultra-low power ‘standby-sleep’ when no customer is close and to use a motion sensor to trigger playback when motion is detected. Buttons and touchscreens can be used to regulate and control further content delivery.

Super Short Power Up Interval

The time taken to change from low power sleep to content playback is critical for battery powered solutions as a customer approaching or touching the display will bring it to life. Low-Power Play enables displays to boot up instantly(within less than 2 seconds) every time they are activated , delivering your message immediately and effectively. Many displays on the market take several seconds to power on leaving customers seeing the ‘power up’ screen and most likely moving on to a more compelling promotion.

Extra Smart Features

Without Low-Power Play, high footfall and busy areas will cause multiple activations of motion sensor or button playing your content continually but with minimal benefit. With battery life measured in numbers of playbacks, early battery depletion will quickly occur. Low-power Play has a customizable playback profile which is configured to limit and regulate the number of times content playback is triggered within certain creative time parameters. For example, for high footfall & busy areas, a delay interval could be set in the firmware which is specified to keep the standby-sleep for the preset interval after each activation, then for human motion of people leaving out the active area, activation will be disabled. Then your customers get the message you want to deliver while Low-Power Play controls content playback and battery usage.

Power Mixing

Many deployments of displays are a mix of AC mains and battery power. Low-Power Play auto-detects battery or AC power mains usage delivering seamless performance across all your power environments. Installers and store staff don’t have to change settings or manually switch the display from one mode to another; Displays automatically deliver AC power mains-style continual playback or battery style activated playback depending on what power source is detected. Smart Design!

Using battery power for shelf-edge displays is a recent development in the digital displays market and is highly attractive to retailers. It neatly and simply overcomes the common issue of distributing mains power to the shelf-edge and avoids complex and costly installations or trailing cables.

However, battery power can appear complex – how many batteries, what type, how long will they last? What type of display works best? What type of content? AOK Displays now has thousands of battery powered displays deployed in many different environments and we have real experience of how to get the very best out of scoping and deploying both battery and mains powered displays. This guide aims to answer the most common questions.

Which Displays Can Be Battery Powered ?

AOK Displays Minis (4.3”) and Shelf-edge ranges (7” & 10”) are most commonly used with batteries. Other sizes can be supported under our custom options. Movement sensor, button and touchscreen features are all supported by battery power.

Is Display Functionality The Same As On Mains Power ?

Functionality is not affected by power type, but adjustments need to be made to conserve power when using batteries. In most cases this is achieved through use of a movement sensor. Video length should also be kept short. Continual play of video is generally not recommended unless frequent battery changes are feasible.

What Type Of Batteries ?

We use D-type alkaline batteries as standard for all our displays as these give the best performance to size ratio. (Check Wikipedia link For D-type alkaline battery dimensions & capacity), since the battery capacity varies from 12,000mAh to 18,000mAh, We choose the middle size at 15,000mAh 1.5V per pc.

Regarding the battery power capacity, 8pcs of D batteries will constitute 15,000mAh 12V when the batteries are connected in series; 24pcs of D batteries means 45,000mAh 12V if they are connected in series for each 8 pcs and 3 set of 8pcs D batteries packs in parallel.

What About Rechargeable Batteries ?

Rechargeable batteries have a different cost and logistical profile to alkaline batteries making them more of a custom solution.

Problems Of Rechargeable Battery, Taking Li-polymer Battery For Example:

>More Expensive, 15 times of battery pack cost.

>Special logistics solution required due to the safety issue;

>Special Battery Charger Required, Trained human maintenance

 

How Are The Batteries Housed ?

Batteries are housed as illustrated in a separate pack with a wired connection to the display. The battery pack needs to be accommodated along with the display on the shelf or in the POS structure. Batteries can be arranged to give some flexibility on pack shape.

How Many Batteries ?

AOK Displays mini screens use batteries in multiples of 4, Shelf-edge displays 7 & 10 inch in multiples of 8.  The number required will depend on how long they need to last, any size or weight limitations and budget.

Regarding the battery power capacity, 8pcs of D batteries will constitute 15,000mAh 12V when the batteries are connected in series; 24pcs of D batteries means 45,000mAh 12V if they are connected in series for each 8 pcs and 3 set of 8pcs D batteries packs in parallel.

What’s the basic power consumption of the shelf-edge displays ?

Taking 7 inch shelf-edge for example,

Working current 250mA in video playback mode;

Working current 2mA in sleep-standby mode;

25 seconds video playback for each activation, 200 times activation (video playback) per day.

The power consumption per day:

Video mode: 25seconds/3600*200times*250mA=347.3mAh

Standby mode: 2mA*[24-25seconds/3600*200]=45.3mAh

The daily power consumption is 392.6mAh.

How Long Will The Batteries Last ?

Considering the discharging curve, when the voltage drops down to 4.2V below, the unit stops working. So roughly, only 65% of battery capacity is effective.

With the cast of the above mentioned 7 inch shelf-edge, the 8D battery pack would support 25 days.

15,000mAhx65%/392.6mAh=24.8;

All AOK Displays Screens have been tested with different battery configurations to arrive at total play time for each combination. For applications where batteries power continual content playback, the figures in the table below give total hours of life. For applications where content is activated by sensor or button, then battery life is determined by the duration of the content played back and how many times a day playback is activated.

Calculations & Examples

Your priority may be to ensure batteries last as long as possible, in which case you will want to keep your video content brief and use a maximum power battery. However, if you have merchandisers who can regularly change batteries and you want to keep the shelf-edge footprint as small as possible then a smaller battery pack is likely to suit you best. Alternatively you may have a fixed duration campaign and need to power displays for just this period. The calculations and examples below show how to identify the best fit for your promotion.

How Many Times Will The Video Play ?

The tables below show how many times a 20 second video and a 25 second video will play using AOK Displays screens and a selection of standard battery pack sizes. Shorter videos mean longer lasting batteries!

Working current at video mode for 4.3 inch mini display: 200mA;

Working current at video mode for 7 inch shelf-edge display:250mA;

Working current at video mode for 10.1 inch shelf-edge display:560mA;

Number of plays of 20sec video	4D	8D	12D	24D
4.3” Mini Display	5400	8775	17550	35100
7” Shelf-edge Display	–	7020	10800	21600
10” Shelf-edge Display	–	3132	5090	10179

Number of plays of 25sec video	4D	8D	12D	24D
4.3” Mini Display	4320	7020	14040	28080
7” Shelf-edge Display	–	5616	8640	17280
10” Shelf-edge Display	–	2506	4072	8143

 

The above data is measured with 65% battery utilization and in continuous video playback mode.

What Batteries Do I Need For This Campaign ?

Calculations For A Fixed Campaign Length.

If you know how long you want your batteries to last, calculate your requirements as in the following example: Display: 7” with motion sensor

Campaign: 6 weeks = 42 days

Video length: 20 seconds

Average number of activation per day: 100

Play time per day = 20 x 100 = 2000 seconds (138.9mAh per day)

Add standby mode power consumption 46.9mAh per day, equivalent to 34 times of 20 seconds video;

{Standby mode: 2mA*[24-20seconds/3600*100]=46.9mAh}

Total play time required = 42 x 20×134 = 112560sec = 31.3 hours

As a 7” display is being used, then the batteries required to power the campaign are 8D which give 39 hours of play.

How Long Will This Battery Pack Last With This Display ? Calculations For A Given Battery Pack Size

You may need a particular battery pack due to constraints of size or budget. To work out how long the batteries will last, calculate as in the following example:

Display: 10” with motion sensor

Battery pack required: 12D;

Battery pack life: 28.3 hours;

Video length: 25 seconds;

Working current in video play mode:560mAh;

Average number of activation per day: 50;

Play time per day: = 25 x 50 = 1250 seconds;

Standby current:2mA( max)

Standby time power consumption equivalent to video playback

Add 304 seconds per day to for standby power consumption = 1554 seconds per day = 0.432 hours per day

{Standby mode: 2mA*[24-25seconds/3600*50]=47.3mAh, 47.3mAh*3600/560mAh=304seconds}

Divide battery life by hours per day = 28.3/0.432 = 65.5 The batteries in this example will last 65 days (9 weeks)

Number of plays of 25sec video	4D Battery Pack	8D Battery Pack	12D Battery Pack	24D Battery Pack
4.3” Mini Display	30	48.7	97.5	195.0
7” Shelf-edge Display	–	39	60	120
10” Shelf-edge Display	–	17.4	28.3	56.6

Battery Life* with AOK Displays Low-Power Play *Batteries tested at 65% utilization.

Today’s consumers are quite familar and informed with some in-depth technical specifications and they want to stay with their obsessions about those high profile technical parameters. This new consumption trend brings great challenges to brands of Hi-Fi headphones, earphones, speakers & soundbars. When building a retail audio POP system, which helps shoppers try and compare the sound quality of products in the field, audio brands’ product managers try to go to extreme asking for 32-bit digital output at sample rate of 384KHz.

Technically, this is reasonable if we look into the following chart which explains the audio signal flow during retail demonstration, taking headphone retail demo for example:

Say if you have USB audio DACs to get 32-bit audio at sample rate of 384KHz from the 32-bit compliant ARM processor( it requires USB audio class driver at the low level to support), or you can even use some higher end DAC which delivers a DNR of up to 127dB and THD+N of -120db, whose performance level should satisfy the most demanding audio enthusiasts, next you will need a good amplifier to drive the headphones, the most complicated part of which is tuning the amplifier to match the expected audio characteristics of the headphones.

Common sense is that digital audio signal is NOT audible, what people can hear is analogue signal, so to build an impeccable retail audio POP system for real audio enthusiasts, if the analogue part is not tuned up, 32-bit @ 384KHz digital output does Not make any sense.

We have to point out that high quality digital input is not the king, the most important part is the analogue: DACs and amplifier. Unless for headphones with retail price above 1,000USD, it is not suggested to mislead shoppers using 32-bit DAC, due to the super large size and scarcity of 32-bit 384KHz music files. Actually in most cases, 24-bit 48KHz is quite competent for retail audio demo. Why ? CDs use a sample rate of 44.1KHz, so we say 48KHz is not that bad, and 48KHz is a natural choice of audio sampling in digital television applications  such as DVD and HDTV. Most importantly, what shoppers finally need is an audio product with high performance price ratio when they make any buying decisions.

Here are some typical wrong understandings about Hi-Fi audio:

No.1: Strong bass means Hi-Fi.

No.2: High clarity means Hi-Fi.

No.3: Hi-Fi is for all kinds of music.

High-fidelity (Hi-Fi) means high quality reproduction of sound (https://en.wikipedia.org/wiki/High_fidelity) , ideally high-fidelity means minimal amounts of noise and distortion with an accurate frequency response.

You may note that high-fidelity is 50% objective and 50% subjective, for a branded headphone, hearing experience from a professional piano player and non-professional can be totally different in terms of sound “distortion”.

To satisfy the real audio enthusiasts, audio brands need professional audio design engineers who understand and love music like a music performer to perfect the design for high quality audio transmission from digital to analogue, and tune the sound both objectively and subjectively. AOK Displays is partnering with leading headphone brands and taking advantage of their acoustics lab & professional team for analogue audio tuning. We are happy to be able to offer the most impeccable audio retail demo system to please the fussy and demanding market, to see is to believe, check out the tech-data as below:

Digital:24bit /48KHz DAC,

Aanlog:SNR:105;

THD+N: 0.02%;

Frequency Response Range: 20Hz—-20KHz

(Tuned By Audio Precision AP2700)

Please click through the following for ready soundbar, headphone, speaker demonstrator,

Soundbar, Headphone, Speaker Retail Audio Demonstration

For project oriented inquiries, please contact us directly for more information.

Top 6 Commercial Tablet Android Solution Processors:White Paper, Design Norm & Performance Comparison

	Rockchip RK3288	Rockchip RK3188	Amlogic S905	Allwinner A83T	AllWinner A33	Amlogic 8726MX
Processor	Quad-Core Cortex-A17, 1.8GHz	Quad-Core Cortex-A9, 1.6GHz	Quad-Core 64Bit Cortex-A53, 2.0GHz	Octa-Core Cortex-A7, 1.6GHz	Quad-Core Cortex-A7, 1.5GHz	Dual-Core Cortex-A9, 1.6GHz
GPU	ARM Mali-T764	ARM Mali-400	ARM Mali-450MP6	PowerVR SGX544	Mali400MP2	Mali400MP2
RAM	2G	1G	2G	1G	1G	1G
Video	4Kx2K H.264/H.265 10-bit	1080P @ 60fps	UHD 4K 60fps hardware decoding, H.265 10-bit	1080P @ 60fps	1080P @ 60fps	1080P @ 30fps Hardware decoding
Connectivity	WiFi a/c	WiFi b/g/n	WiFi a/c	WiFi b/g/n	WiFi b/g/n	WiFi b/g/n
Gigabyte Lan	Supported	Not Supported	Supported	Not Supported	Not Supported	Not Supported
HDMI 2.0	Yes	No	Yes	No	No	No
Applications	Commercial & Retail Tablets	Commercial & Retail Tablets	Commercial 4K UHD Media Player	Android POS Terminal & Commercial Tablet	Android Touch Controller For Home & Industrial Automation, entry-level retail tablet	Android Touch Controller For Home & Industrial Automation, Retail tablets

Among all the ARM processors listed as above for commercial tablet advertising, we would like to put RK3288 on the top of the performance ladder, due to the obvious key factors including 4K video decoder, 5G WiFi (802.11 ac)  & Gigabyte Lan for multi-cast IP streaming. The other reason why RK3288 gains the top position is that tablet advertising professionals learned from the mistakes, failures, and drawbacks of what they got from the long learning curve of RK3188, the No.2 runner of the commercial tablet performance racing.

Rockchip RK3288 mother board diagram

And RK3288 is introduced together with Android 5.1, this version of Android carried some expectations that are not available in the widely accepted & popular Android 4.4: screen pinning (multi-screen), and there are quite more apps available based on such a newer version.

The benchmark of commercial tablet is Allwinner A20 powered tablet display and Rockchip RK3188 based retail tablet. When Allwinner is more developer-friendly, A20 is widely used for tailor-made commercial, retail & industrial applications when peripherals & device communication are needed.

Allwinner A20 Mother Board Design Norm

Rockchip RK3188 as a follower, starts retail & commercial application from a designed-for-price consumer-line mother board. Thanks to Rockchip’s partnership with Intel which sends a clear signal to industry that Rockchip gained entrenched advantage in reputation which influences the end-users and the buyer-preference based marketing finally helps Rockchip won over the market share of commercial tablet market that was previously occupied by Allwinner family.

RK3188 Classic mother board with extension interface for RJ45

RK3188 mother board with 3G module slot

Allwinner A83T, the Octa-core processor, entered the market with a super short boot up time(as short as 10s), for comparison, RK3188 is almost in the same level as A83T in performance.

Allwinner A83T mother board diagram side A

Allwinner A83T mother board diagram side B

With A83T targeting the middle & high-end market, Allwinner released A33, the down-performance model of Allwinner A20, it was designed for small sized screens like 10.1” or below sized retail tablet, business hospitality tablet used for room management (touchscreen controller for example).

Allwinner A33 mother board diagram

Amlogic family, owned by Chinese and headquartered in US, it entered the commercial tablet market earliest since 2012 when dual-core processor was new to mass market. Amlogic is operated in a westernized way to buy up-to-date advanced IP for its ARM processor, it is NOT developer friendly, but it is built with managed engineering & due consideration for long-term-win strategy. We choose it for openframe touch panel at the early stage when hardware options are very few. We built abundant communication interface for various commercial applications, see the following circuit diagram.

In early 2014, after CES, 4K became a tech-topic in the industry, RK3288 took the lead again, but due to its market-first strategy, it is mass production ready until later 2015 for commercial use. During this time, Amlogic learned the market and released 64-bit quad-core S905, it gained the top position in 4K set-top-box market thanks to its great success in tele-operator market. Amlogic’s main know-how for commercial application is the color reproduction and hardware video decoding. Our MP40 is one of the very few commercial use 4K media player that can run for months without failure. But due to the fact that Amlogic S905 does’t have built-in LCD panel interface, it lost the power for high-end commercial tablet, while RK3288 takes the lead again and occupied the market.

In a long-term, the solution design norm for mass market belongs to Rockchip, from RK3188 to RK3288.