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The 'VeloCharger' USB bicycle charger - Review


The VeloCharger is a USB bicycle charger that is designed to take the raw AC voltage from a bicycle Hub Dynamo and converts the voltage to a stable 5 volt DC supply suitable for charging a mobile phone or other USB device.

The VeloCharger is black plastic injection moulded unit that measures 32mm x 25mm x 106mm and weighs 54g. Built into one end of the VeloCharger is a recessed integral USB socket to accept a standard USB charging cable.

Here is the manufacturers description from the information leaflet that came with the VeloCharger:

Using a standard 6volts 3watts dynamo, VeloCharger will start charging at 10mph (16km/h) and will provide a 1Amp charge to a phone or other device at 12.5mph (20km/h). Hub dynamos can give a high voltage output at speed , and the VeloCharger will cut out at speeds exceeding 30mph (48km/h) to protect the circuitry. At sustained speeds of over 40mph (64km/h), the VeloCharger should be disconnected from the dynamo to prevent damage.

The version that I am reviewing here is the Hub dynamo version, apparently the manufacturers do make a version that will attach to a bottle cage dynamo.

The VeloCharger is made by Adept Electronics, 23 St Martins Lane, Beckenham, Kent, BR3 3XU, United Kingdom. There is more information on the VeloCharger on their website:


VeloChargerTo install the VeloCharger you will need some basic skills and wiring tools such as a pair of wire strippers as the cable that is supplied needs the outer insulation removed and the sheaths stripping off the two wires inside. Unfortunately the VeloCharger didn't come with any 4.8mm spade connectors that connect to a standard SON dynamo hub therefore if you have that type of hub you will have to purchase some separately. Luckily I had some spare 4.8mm spade connectors and after stripping the wires back these were crimped on to the wires, although I prefer to solder these on as you get a better join and electrical contact. If you are using your Dynamo hub to run your cycle lights you will need to use a pair of 4.8mm piggyback spade connectors.

The manufacturers suggest mounting the VeloCharger at the top of your down tube and there are two small Velcro pads which you can stick on to the VeloCharger and onto your frame and a Velcro strap to hold it securely on. Unfortunately the down tube of my Koga Worldtraveller-S was too large for the Velcro strap so I had to fit the VeloCharger to the handle bar stem. In fact there was plenty of cable to do this and I could easily have placed the VeloCharger inside my barbag. However although there was no mention of it in the information that came with the unit I was concerned that it might be like my igaro charger and need to be outside so that it could be air cooled. The cable was safely attached to the front forks with the supplied cable ties.

Although in the fitting instructions it does say:

'Ensure that the dynamo cable is pointing forward'

It is important that where ever you fit the VeloCharger that the USB port is pointing downwards. This is to stop the ingress of water when it is raining although even with the VeloCharger fitted on the down tube there is the possibility of water spraying up from the wheels particularly with a bike fitted with no mudguards.

The VeloCharger comes with a waterproof connector that you can use to disconnect the VeloCharger from the dynamo lead to prevent it from being stolen when you leave your bike unattended.

How well does it perform?

Well I can honestly say that it does perform very well and the VeloCharger is a very capable USB charger. I have been using it on day rides and have used it on our latest tour in Norfolk and Suffolk and in the two weeks it helped to keep my phone reasonably well charged.

There are some caveats to that last statement. Like all of these dynamo chargers you only get out what you put in. The charger only starts to charge at about 8mph (13km/h) and seems to give out its best output at 12.5mph, which according to the manufacturers is 1amp (although in my testing I didn't quite get that, but that might be my tester not being quite accurate). If you don't ride most of the time over 8mph or at 12mph you won't get much output from this or any other USB charger.

USB TesterIf I compare the VeloCharger to my previous Igaro D1 charger it is certainly much better. Using a 6 mile circuit that I do at home I connected the two chargers to my Samsung Galaxy S10 smartphone on two separate occasions with a small USB tester that can measure capacitance. I did two loops one after the other with the two chargers and I tried to keep everything the same and riding at the same average speed at over 9mph. On the first loop, with the igaro the USB tester I only recorded 36 ma/h of capacitance during one circuit, where as with the VeloCharger on the second loop the USB tester recorded 161 ma/h of capacitance charge on the same circuit. I repeated this on several other days and consistently the VeloCharger produced similar higher capacitance compared to the Igaro D1.

I mainly use the VeloCharger to charge my Samsung Galaxy S10 smartphone but I have used it to charge a small power-bank and to run my Garmin Oregon 750T GPS. Although we haven’t tried it I understand that it will charge an Apple iPad.



  • A well made piece of kit, which in the year or so that I have been using it it has not failed and has performed well.
  • Solidly constructed.
  • An excellent price at £67.50. It easily out performed the igaro D1 which was twice the price.
  • Fairly easy to install.
  • Can be removed from the bike for security.


  • At sustained speeds of over 40mph (64km/h), the VeloCharger should be disconnected from the dynamo to prevent damage. You could easily forget to do this on one of those lovely alpine descents.

If you tend to ride at an average speed of over 9mph then this is a very capable USB charger and is a snip at £67.50.