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Igaro D1 Model 5 USB power converter for bicycle dynamo hubs - review

Igaro D1 chargerFollowing the demise of one of our Busch & Müller E-werk chargers (where the power lead came away from the main body, apparently a common problem). Rather than buy another E-werk we decided to look around at other charging systems that are now currently on the market since we bought the E-werks a few years ago. Doing a Google search we came across Alee Denham's excellent site which has a very good list of all the current USB chargers available to the touring cyclist along with some good indications as to their charging abilities.

One charger on that list that caught our eye was the Igaro D1. Not only did its stats looked good against the others when charging but it also had two usb output ports that would give us the ability to charge two devices at the same time.

We recently reviewed our charging system for all our electronic devices and decided to simplify things by going all USB. Where previously we had gone for the E-werk with its ability to vary the voltage and current output so that we could charge at either 5v or 12v we decided that by buying a USB camera battery charger we could eliminate the need to charge at 12v. It has always been a bit of a faff to change the voltage on the E-werk and on one occasion I forgot to change it and blew the battery in a phone. Having made the decision to go completely USB we decided to take the plunge and bought the Igaro D1.


Igaro fitted to my bikeInstallation was fairly simple although when you order the Igaro D1 Model 5 from the Igaro website you will need to order the correct power lead that fits your Dynamo system. We have the Schmidt SON 28 Dynohubs fitted to the front wheel of our bikes so we ordered that lead. The lead came with piggyback connectors so it was easy to connect in our B&M dynamo lights. Even though we have quite high mounted handle bars the power lead was just long enough to get the USB connectors in the right position so that the USB ports leads would go into our barbags. All the components were mounted with cable ties although I did place a couple of pieces of heat-shrink over both the spade connectors on the dynamo lead to stop them from shorting out if they touched.

One thing Igaro stress is that when mounting the igaro D1 it should not be placed in a bag or enclosed space:

 'If the bicycle travels at such a speed whereon the dynamo hub produces too much voltage then the Igaro D1 will protect itself by dissipating this as heat. If this heat can not dissipate by way of airflow the Igaro D1 will be permanently damaged.'

Compared to the E-werk the Igaro D1 is much smaller and I cable tied mine to one of my brake cables and to honest and you can hardly see it and it resides there permanently, it is so discreet that not many people would know what it is.

The Igaro D1 system comes with a stability bank which is basically a large capacitor. This is how Igaro describes how it works:

'This accessory boosts an Igaro D1's performance at low speed and/or enhances compatibility with some fast charge devices. It works by smoothing out the very low frequency AC at low speed and temporarily allowing a current surge on USB connect (tricking many USB devices into higher power mode).'

The stability bank which is much larger that the Igaro D1 itself has to be mounted somewhere as well. I found a good place for it under my Ortlieb barbag mount and held it in place by a couple of cable ties.

The USB leads were just long enough that they lie comfortably in our barbags which keeps them nice and dry. However the USB connectors are not waterproof therefore if they are not in a barbag you will need to keep them from getting wet. If the pins get wet they may suffer electrolysis and corrode which could eventually lead to electrical failure. Igaro expect that this might happen as the USB port was never designed for outdoor use and therefore they sell replacement USB ports for the Igaro D1.


So far we have been very impressed with the performance of the Igaro D1. It seems quite happy to charge up a phone and power the GPS or power bank at the same time. At about a speed of 9-10mph (15 -16 Kph) it seems to start charging and from the little USB voltmeters that we have attached to the USB outputs it seems to be giving out 4.7v to 4.9v at about 45mAh with one device connected and when two devices are connected it splits the power between the two. When you come to a stop you can here the beep of the phone as it stops charging and also the GPS comes up with the message 'External Power lost' so you know it was charging on both portsl. On connecting my RavPower 268000mha power bank at 14mph it was charging at just over 2 watts.

Below is the graph from the Igaro site showing the watts output against rpm of various USB chargers.

Igaro Stats

The amount of charge you get from the Igaro D1 very much depends like any charging system on the speed you are doing. On good flat cycle paths and roads where we were averaging above 9-10mph then the Igaro D1 charged fine. On hilly terrain or gravel tracks where our speed dropped below 9-10mph then the Igaro didn't start charging. However if our climbing involved some fast downhill stretches during the day then that compensated for the uphill sections. Obviously as you can see by the graph above the faster you travel the more power output from the Igaro D1.

One thing offered by Igaro is a Solar panel lead so that you can connect a solar panel to the Igaro D1. Solar is used before dynamo power which for lower power requirements will result in reduced dynamo drag. In good sunlight and with pedalling the Igaro D1 can provide up to 3A at the USB port allowing for charging high capacity devices in reduced time. We haven't as yet tried this but it sounds a very useful addition.


We recently used the Igaro D1 on both of our touring bikes on our 4 week tour of Sweden and Denmark and they both worked well. Frank used hers to keep her Samsung phone and Kindle topped up and I used mine to solely charge my Land Rover Explore phone. I wouldn't say that it completely kept my phone topped up as this year I was using my phone for navigation and as a GPS therefore I had the GPS running and the screen on for most of the days cycling both of which are very battery hungry. Certainly if we hadn't had the Igaro D1s charging our phones we would have had struggled on the nights when we didn't have an opportunity to charge our electronic devices from the mains and had to resort to using our powerbanks. Compared to the E-werk power output is about the same however the Igaro D1 has the edge for me as it is a lot simpler to use, no need for cache batteries and it is very discreet.

Pros & Cons


  • Convenience of two USB ports.
  • Easy to fit.
  • Discreet so doesn't look like a steal-able item.
  • Good power output.
  • Works with existing Dynamo lights.
  • No cache batteries needed.
  • Can charge a power bank if needed.
  • Good value for money compared to other USB chargers.
  • replaceable USB ports available.
  • A solar panel can be added to the system.


  • USB ports are not waterproof.

Video of the Igaro D1 Bike test.

You can find more information on the Igaro D1 on their website here