Security Application

NSF Controls improves performance and power consumption for mobile phone charger lockers


ChargeBox Ltd




Charging Lockers

Size of Business: 

Over 2,000 stations have been constructed

Scope of Service:

  • New product development
  • Parts procurement
  • Supplier research
  • Prototyping
  • Testing
  • Bespoke manufacture
  • Assembly
  • Quality control

The situation

A company producing secure mobile phone charging stations contacted NSF Controls, seeking to improve specific areas of product performance. 

In business for over 10 years, its latest stations, with optimised charging, easy to use touchscreen and patented key mechanism, are proving to be the most trusted in the world.  Whether for direct revenue generation, to encourage length of visitor stay or just to provide a service, the number of public venues employing these stations is increasing.

The first commercial models available were six-locker units in free or vending options.

Each publicly placed unit consisted of highly secure lockers in which to place mobile devices while charging for periods of 30 or 60 minutes.  A four-locker wall mounted version was soon to follow.

The challenge

By 2011, the award-winning design had reached a defining moment since its inception. The design was basically sound but was being hindered by two unrelated issues:

  • The solenoid locking system fitted to each compartment was using excessive power resulting in over-heating.
  • The cam lock blocking mechanism was getting jammed in operation.

The solution

How the locking panels worked

The internal workings of the locking panel for each station comprised the following, one set of each per locker:

  • 6 solenoids with connectors
  • 6 brackets
  • 6 blocking mechanisms
  • 6 micro switches

Use of an inadequate solenoid was causing overheating in operation and NSF Controls was briefed to optimise performance to meet requirements and in doing so, reduce power consumption by approximately half.

NSF Controls identifies opportunity to avoid overheating issue and reduce power consumption

On assessment, it was apparent that the space available was adequate to fit a slightly longer solenoid with reduced current. Thus providing more force, but using less power.  A moderate increase in production costs would be offset by extension to longevity and therefore be easily recouped over the lifetime of the finished product.

Bespoke engineered design improves operation

The solenoid itself operated a blocking mechanism to prevent engagement of a conventional key cam lock.  When in operation, the freedom of angular movement available to this aluminium block frequently resulted in it becoming trapped in the latch slot. 

NSF Controls' engineers designed a robust plastic moulded blocking piece with integral skirt secured to the solenoid plunger. In effect the solenoid and blocking piece became one component, virtually eliminating the possibility of misalignment.

These alterations to size and profile of the solenoid meant its positioning and fixing on the panel plate also required adjustment. The solenoid location tab on the steel bracket would need moving along to cater for the increased solenoid length.

Another concern was the space gap between the plate and the solenoid coil housing. Should the key be operated in an awkward or heavy-handed fashion, it could dislodge the component.  After client consultation, NSF Controls sourced a supplier and submitted a redesigned steel panel plate. The location tab on the bracket was resituated accordingly and a raised steel lip was added as a means of reinforcement for the solenoid body.

With this project completed successfully, the partnership with NSF Controls was extended to include complete assembly of the locking panel.  NSF Controls was asked to perform supplier research and selection for micro switches and proceed to build the subassemblies for four and six locker models in their entirety; first for testing of the market and then increasing output according to demand.

The results and future

Continued product development

Over the years NSF Controls' client has worked on all aspects of product development and adapted strategy to meet market demands. Now the world’s leading secure, away from home, mobile phone charging business, the company launched its own App to guide users to the nearest charge station.

Growing customer base worldwide

In 2012, the company was asked to install 23 units into Westfield Stratford City, to service the Olympic venue, as well as 5 units into Westfield London. Its portfolio is growing and includes shopping centres, railway stations, nightclubs and visitor attractions like Madame Tussauds.

In excess of five million charges have been successfully provided so far with four million more charges forecast annually. To-date over 2,000 stations have been constructed, more than 50% of these exported to 17 different countries.

To find out more about NSF Controls, click on the information below 

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