Igaro D1 Mod 5 (d105) USB Power Converter for bicycle dynamo hubs

The Igaro D1 is a well-made and highly configurable way of getting USB power on your bike from a dynamo, or solar panel, or both. The output is higher than other options and the build quality, with the titanium-bodied main unit and waterproof connections, is excellent. You're not tied to a specific positioning and it's easy to make it work with whatever setup you're running. Overall, it's really good: not cheap, but worth the money if you want to charge devices on a multi-day adventure.

• Pros: Excellent build quality, high output, serviceability, multi mounting options
• Cons: Not cheapest

Fitting the D1 is pretty simple, really. I originally asked for a Shimano power lead (bare ends) but I ended up fitting it to a SON dynamo on a pair of Hunt Superdura Dynamo Disc wheels (review coming soon). The SON hub came with spade connectors, so I just crimped them on to the leads and all was well. The Igaro SON lead features a pair of piggyback connectors so you can run a light in parallel, but I didn't miss those as there's also an output for a light from the D1 itself.

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All the connections on the Igaro system are fully waterproof, and you just screw together the bits you need. For me that was a power lead into the D1, and a light lead to a Supernova E3 lighting system out of the other end. I also added a Stability Bank, which smooths out the power supply and means that the D1 works better with higher-power USB devices. That's included with the model 5 D1.

You can also add a power switch (£17.59) which can route the power either to lighting or to USB, rather than trying to run both. I mostly didn't use that as the E3 front light is easy to switch on and off, leaving all the power for USB when you don't need light. But I did plumb it in to confirm that it works. Which it did. The switch can be fitted through a solid panel in your luggage, or you could use washers or a bit of backing board to fit it to something more flexible. There's also a solar panel input, which I didn't try as we'll not see the sun round these parts until May at the earliest.

Although the D1 and its connections are waterproof, the USB standard itself isn't designed to be. The D1 model 5 has two USB ports with gold-plated connections to resist corrosion and they're designed to shed water if they get wet, but it's better to keep them out of harm's way as the close proximity of the connections means it's easy to short them in wet weather, and they can degrade quickly when wet.

I fitted the D1 itself to the stem of my bike, and ran the cables into a frame bag. I had to pick the seam of the bag and seal it round the wires, but it turned out to be a very neat solution. I could run a USB cable back out for in-situ charging when it was dry, or if conditions were more changeable charge a powerbank inside the bag, to top up devices when I stopped.

Two USB ports means you can charge two devices at once if there's enough power, and there's also some redundancy: if one goes south, you still have the other one. Igaro will re-wire your D1 for free if one of the USB ports dies; the whole of the Igaro system comes with a five-year international warranty.

Pedal power

The USB takes a short while to kick in from the off; it's designed that way so that the USB supply doesn't cycle on and off while the wheel is spinning up to speed. It's very stable once you're over about 12-13km/h and feeds a useful amount of energy into your devices. If you want USB power and lighting going, you need to be cracking along faster than that, and it'll depend on what you're charging. I generally found that the D1 worked best using either one or the other, which is no great surprise, but on flatter rides it's possible to use both effectively for a decent proportion of the time.

Whether you get enough juice out of the D1 for all your charging needs will depend on how many devices you've got on the go. If it's a phone, or a phone and a Garmin, you'll probably be fine. If you're adding a camera, or a GoPro, or a tablet, or all of the above you'll eventually get to the point where you're not generating enough energy to keep everything charged. That's not a limitation of this system: dynamos only output so much power.

The SON Delux dynamo is a quality unit, although it doesn't have the highest output out there, and I had no issues keeping a Garmin and a phone charged. Generally I charged by dumping the dynamo output into a powerbank, and topping up devices from that. I mostly used a 7800mAh Topeak one and I have a smaller 5,000mAh one too.

Direct charging or bank it?

Charging a battery, and then using that to charge your bits and pieces, is introducing another step and therefore it's not necessarily as efficient as charging directly, but generally, I found it worked better. One reason is that my powerbanks are less fussy about the charging current than my phone (especially) and my GPS are.

The phone (a Sony Xperia Z5 Compact) is about as picky about its charging current as phones get, and didn't always want to charge direct from the dynamo; it's a bit funny about charging from certain ports on my computer and certain wall chargers too.

Also, Android devices can be a bit funny about the charging circuits switching on and off, and mine reset itself a couple of times when I was doing stop-start riding through town; again, that's more an issue with the phone than it is with the D1. The powerbank isn't as demanding: if you're pumping juice into it, it'll store it, and it doesn't seem to mind the charge cutting in and out.

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The other benefit is that when your devices do need charging, the battery has a 2.4A output that makes short work of it. So even short café stops allow you to make a significant impact in the charge. There's also less chance of having issues with waterproofing: if your strategy is to charge a battery and keep your devices topped up when you stop, you can make sure the charging setup is completely protected from the rain.

Not sure what the consensus was on charging, I asked the question on the Transcontinental Race Facebook group. The results are that there isn't a consensus: it's pretty much an even split. Some people charge devices directly, some charge a battery from the dynamo and use that, and some just carry a battery and rely on mains power to top it up when they stop. Whatever works best for you, I guess.

Consider the options

If you want USB power on your bike then the D1 isn't the cheapest way to go about it: a Busch & Muller Luxos light with a USB output will set you back about £100, for example, and you're getting a front light for that too. But most of the other systems don't get anywhere near the 3A that the Igaro can output, if your dynamo is capable of supplying that much power; most are between 0.5A and 1A. Few of them are as waterproof (the D1 is IP69 rated, which is about as good as it gets) and not many are serviceable.

The thing I like most about the D1, though, is the fact that you're not tied to a single setup. If you're fitting a Cing5 Plug, for example, it has to go in the top of the steerer, which can cause problems if you have a phone mounted on your stem, or your fork doesn't have a hole in the crown for a dynamo wire. If you're using a Luxos USB light then the control button really has to go on your handlebar, and then the short USB lead limits your options for getting the port somewhere dry.

With the D1 you're not as limited. I've mounted the unit on my stem, but it can go on the fork leg, or under the handlebar, or on the frame: whatever works best for your bike, and your luggage. You can add a control switch if you need one, or leave it out. You can plumb in a solar array if you're going somewhere sunny, or leave it out if you're staying in the cloudy and dull UK. That, combined with the excellent build quality, the high output, the USB redundancy and the serviceability, make it – for me – the best solution for reliable USB power on your bike.

Verdict

Really well-made and versatile USB power system for your long-distance bike