Sometimes it is the simplest things that prove to be the most irritating. Take the humble cigar lighter power plug in the car for instance. When most MCUG members ran their own fleets of liveried vehicles and had teams of fitters in workshops ready to fit bespoke mobile computing or wireless handheld devices, both the cost of the fitting and the resolution of any technical problems could be taken for granted.  And the costs would probably get lost in the overheads. With substantial wires run straight to the vehicle battery, what could go wrong?

Today most service businesses are quite lean; many lease their vehicles and use a range of sub contractors to deliver key services. So, where does the cigar plug fit in all this? Well – with most of these mobile businesses, managing work dispatch, work management, and technical support via the mobile computer, that device is now absolutely critical to profit, loss and service levels. The need to deploy, and re-deploy, the mobile IT systems in a wide range of vehicles, has increased the dependency on flexible solutions, and therefore on systems that draw power from the cigar socket. Modifications to vehicles such as wiring modifications can now incur penalties from the lease companies, or are a problem for itinerant contractors, in yet, without reliable power jobs can be lost, and communications will fail.

On a show of hands, at any meeting that I attend, plugs, sockets and wires come an easy top in the unreliability stakes, and this hasn’t changed in ten years. The only minor improvement I’ve noticed is that anti-smoking policies seem to have helped keep the power sockets a little more free of ash and WiFi/Bluetooth has reduced the count of smaller data cables. The combination of various vehicle manufacturers’ ‘sockets’ and the range of cheap-and-cheerful plugs make intermittent power connections a certainty.

The European E marking of vehicle electronics has done nothing to help, and where manufacturers have fitted extra accessory sockets, these still fail to solve the problem, not having any basic retention devices. As far as I can see, the only body to attempt to bring some reason to the cigar sockets situation has been the US based SAE (Society of Automotive Engineers) who in 1997 issued a standard (SAE/USCAR-4). Unfortunately, although controlling some features and details, this was something of an acknowledgement of the status quo, again failing to require a good locking mechanism, which is what the users needed. Those sockets that are actually used to light cigars do have a spring clip at the bottom, and that clip is defined in the SAE standard, but sadly it is a weak thing, so that the lighter plug can ‘ping’ out when the cigarette lighter is hot. A case of nearly, but not quite!

Recently one MCUG member reported a small but significant number of problems with melted cigar plugs, or more correctly, melted plug-tips.  Their computer systems could, under some circumstances, draw approaching 10 amps from the vehicle, although under most situations the current was far less. My investigations uncovered several failings in the current plug design. The most interesting in this case being that the spring used to push the tip against the contact was made of thin steel wire. This nicely kept the tip and its associated fuse in contact, however, at full current both the fuse, and the thin spring wire got hot; so hot in fact, that they melted the plastic tip, which then failed. If the spring is too thick and strong, then it works the other way, and the plug stays cool, but is pushed out. Either way the design was necessarily a compromise and opened the possibility of staff getting burnt fingers! Sadly, there are not many options that are much better. The real shame is that these things are supposed to be powering £2000+ worth of in-vehicle IT, and are a critical link in the work management business process for the user.

I will spare readers the many other findings that went in my report, save to say that we are now under way with more tests, and evaluating other plugs and vehicle sockets. MCUG would be very interested in any other comments on plugs in service either successful, or disastrous. If you have some experience, good or bad, then please get in touch. Tantalisingly, I was once briefly shown a plug with a special locking device, but, just like the oasis in the mirage, further searches have been in vain.