Author Topic: Charging iPhone on the road  (Read 1849 times)

Pete Taylor

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Charging iPhone on the road
« on: September 12, 2018, 11:01:00 PM »
Can anyone help a newbie in this touring game? This year I have had the good fortune to buy a Thorn Tandem and it is terrific in almost every respect. One glitch is my inability to charge my iPhone as I had expected to. I wanted to use the iPhone for MapMyRide app and potentially route finding. With advice from Thorn, I opted for a Son 28 dynamo unit in the front wheel, a Son Edelux II headlight and a Sinewave Cycles headset USB socket. When I connect my iPhone and cycle we get an encouraging “ping” telling me that “charging” is happening as we cycle along however the iPhone 6S battery runs down just as quick as if we were standing still! I have to admit that my wife and I are not Mark Cavendish and Bradley Wiggins in concert. We average 12-15km/hr over a 4-6hr back ride. I have the Headlight turned off and I am using an official Apple cable.
What am I doing wrong? Am I just not cycling fast enough? Should I use a pass through battery pack?
Thanks for any suggestions,
Peter Taylor


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Re: Charging iPhone on the road
« Reply #1 on: September 12, 2018, 11:22:07 PM »
I have the same front wheel dynamo on my Thorn and it is wired into both a Supernova Headlamp plus rearlamp and a Cycle2Charge V2.
Cycling at similar speeds to you I can use my iPhone SE to show progress on a map using GPS and still end up with a charged battery - as long as I switch the lights off. I also have everything not in use switched off on my phone.

You are doing nothing wrong, maybe the charging circuit in your Sinewave device is not powerful enough for your iPhone.
Possibly the phone is doing other processing which could be turned off.
It might be a faulty cable, worth trying another - I use an equivalent Anker cable on my bike.

John Saxby

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Re: Charging iPhone on the road
« Reply #2 on: September 13, 2018, 04:00:32 AM »

A couple of observations, which I hope are useful, though they don't directly answer your questions --

I have a SON 28 dynamo on the front wheel of my Raven, hooked up to a Sinewave Revolution charger. There are two circuits (fed by piggyback connectors on the tabs of the SON 28), one for a headlight and one for charging a battery or a device such as a phone.

1)  for the iPhone:  I seem to recall reading that Apple products (phones and tablets) are not happy with the variable current from a dynamo.  I've been using Macs for 35 years, but not IPhones or iPads, so I don't know that's the case.  Might be worth checking with your tech wallah, though. (The reason I don't have an iPhone is that my tech wallah, an Apple specialist who's maintained my gear for 25 years, tells me that they have a crappy battery, and that when the crappy batt wears out, you have to replace the phone.) (I sucked up my aversion to Google and bought a fairly basic Android phone which has an A-grade battery, a Motorola.)

2)  for the light/charging setup:  I could never find a satisfactory balance between using a headlight (powered by the SON 28) and charging a phone/camera/etc.  My headlight didn't have a flashing mode, so it was either "on" or "off", and when it was "on", it consumed most of the current from my dynamo.

     So, a few years ago I switched to a different arrangement:  I have a very good battery-powered Cygolite headlight, which has a flashing mode. (It has a durable lith-ion batt, and a handy port for a USB cable.)  I use that during the day -- it lasts for 3-4 days.  Note, however: I rarely ride at night.  My headlight lets me be seen -- I don't use it so that I can see well enough to ride in the dark.

     Now, I use my SON 28/Sinewave circuit only to charge a cache battery, a 5200 mAh Anker.  This is a superb device.  It cost me all of Cdn $25 (via Amazon -- this is the only thing I've bought via Amazon in the past few years, but the Anker was not available elsewhere.)  I can charge the Anker from zero in less than a day's riding.  I then use it to charge my phone, my camera, my headlight and tail-light, AAA batts, etc., at night.  As a rule, I re-charge my headlight about every third or fourth day, my phone maybe every other day, my camera every couple of days, etc.  I have a splitter cable for the Anker (an accessory sold by Sinewave -- handy device) so that I can re-charge a couple of things at once. 

     Rarely do I need more than a couple of hours in the evening to recharge my electronic bit 'n' pieces.  (I rarely let them go below 50%.)  With that sort of demand, the Anker is run down by maybe 35-40% at most, and is recharged by noon the next day.

     (One detail about the Anker:  It doesn't have a pass-through capability. If it's being charged, it won't charge something else.)

     I've found that this arrangement is simple, and is now part of my routine when I'm touring.  Bear in mind though, that I use my headlight almost exclusively on the flashing mode, and as a result, I'm not recharging it every night.

     Of course, if you're near the mains when you've finished riding for the day, you don't have to use the Anker.

Hope that's helpful, and not just "more stuff" to think about.  Good luck, in any case!


Andre Jute

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Re: Charging iPhone on the road
« Reply #3 on: September 13, 2018, 07:47:26 AM »
(The reason I don't have an iPhone is that my tech wallah, an Apple specialist who's maintained my gear for 25 years, tells me that they have a crappy battery, and that when the crappy batt wears out, you have to replace the phone.)

This isn't true. Some iPhones have really good batteries, and all the ones I know have replaceable batteries, though it isn't a trivial job to replace the battery. I treasure my all-aluminium iPhone 4S, long obsolete, but still determined to resist the wear and tear of a bicycle life. When I bought it, it had the longest battery life of any decently rugged mobile phone; I have no idea what I will do when it clocks out from advanced technological obsolescence.

Returning to the more immediate concerns of the thread, Apple's gear with built-in lipo batteries have always had hardware programmed to reject attempts to charge the battery at any voltage outside a very narrow range. They did this originally to protect the batteries from a fiery death, their customers from the same, and their profits from massive class actions. But lipo batteries have long been better behaved, and the software to regulate the charge, once accepted at the input port, has matured, but still manufacturers of consumer gear demand very narrow tolerances of electrical input to charge the battery; it may well be that the nanny-states have in the interim made laws about it.

How this works is that the device being charged tries to suck a particular current for the shortest time to full charge as determined by the designer and the available chips, and if the dynamo or whatever the device being charged sucks on cannot deliver that current, the voltage falls, and the charge is rejected at the input. Alternatively, if the cyclist suddenly finds his second wind, or a big downhill, the delivered voltage may shoot up and, since the surrounding hardware to the battery keeps the current steady, the voltage there also shoot up, with exactly the same result: the device the cyclist is trying to charge will reject the charge as out of spec. This is why the circuit for a homemade device I discussed here a few years ago, to get around the manufacturers' CYAssery, had energy-hogging stages to ensure a constant current and a constant voltage, a combination so wasteful that normally no sane engineer would admit in public to even contemplating such blasphemy. Of course, Apple not only has access to digital microchippery designed to do this, whereas a DIY job has to content itself with discrete components (very wasteful of energy dissipated as heat, especially on a bike), but, since they can assume that most customers will suck current either from another battery, as John eventually came to do, which all by itself ensures a constant current and only modest shifts in voltage, or from the wall socket, which is a known, relatively stable supply, so they get away handsomely with their demand for a very narrow-band input. So mostly our problem charging arises because phone manufacturers either have never heard of cyclists, or have dismissed us as fringe niche market.

I've given up on charging from the hyb dynamo, a SON on my everyday bike. Instead I use a Blitzwolf emergency battery made for people who don't take their headphones off even to sleep. It's 3/4 inch square in section and less than three inches long, and literally contains a single lipo battery which is enough to recharge my iPhone 4S three times which in my normal use is three days if I start with a full phone at home, four full charges altogether. But note that I use printed maps, not the phone's GPS; all I use on the phone is the heart rate software which uses Bluetooth, which is a battery killer too, but essential to me. Since the external battery is so compact, I just put it next to the iPhone 4S in the handlebar container, plugged in to the phone, so that the iPhone is always fully charged should an ambulance-type or other emergency arise*. This is a perfectly good arrangement if you know that every second day you'll be near a plug to charge the external battery. Or you can carry a couple of charged- up lipo batteries, which are small though heavy, and just slip them into the container as the previous one becomes fully depleted. As I say, it works for me, but if you have heavier recourse to GPS than my heart rate monitor software (which relates itself to a map via GPS, especially for the elevation, a modest enough use), you'll have to carry a spare, charged lipo battery or two (the lipo batteries I'm discussing are a bit fatter and heavier than a nicad AA). With a 2.4A per port mains-to-USB charger (an expensive but worthwhile thing also by Blitzwolf) it takes about three hours to recharge a current best-available lipo battery from nearly empty. On standby, if you don't use GPS, or any Bluetooth or Wi-fi coms, starting from home with a full battery in the phone and the recharge lipo also full, that will give you up to four days on the road, say three days to be safe, camping wild without any wallwart sockets.

*There's a USB plug on the battery of my electric bike but it is such a hassle running a cable from it to the phone on the handlebars, and so untidy, plus the risk of making holes in a weathertight bag while living in a rainy country, that I just can't be bothered. But in an emergency, one could plug an empty phone into this big battery and instantly have a live phone.
« Last Edit: September 16, 2018, 01:57:23 AM by Andre Jute »


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Re: Charging iPhone on the road
« Reply #4 on: September 15, 2018, 07:02:07 PM »
Anyone have experience of the iPhone SE's battery life? I'm looking for a back up phone and am considering this model.


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Re: Charging iPhone on the road
« Reply #5 on: September 16, 2018, 05:07:33 AM »
The iPhones have pretty much the best batteries and charging circuits that exist.  As opposed to other systems, they do not get charged passively but negotiate a charging rate from the charging source.  Nice thing there is that they can accept a wide variety of charging amperages and won't get damaged if you plug in a too strong charger, but they need several second to determine the rate of charge and with a dyne that does not work as the dyno rate is all over the place.  If one routes it through a cache battery then there is no problem as the rate to the phone is steady, but straight from a dyno does not work well at all. Most old style phones like the Androids take a charge passively.  The phone negotiates a charge.  That is a good thing and good progress, and one of the reasons that the iPhone batteries last so long and stay consistent throughout their expected life, but the designers did not have bicycle dynamos, a charging system from the dyno-saur era in mind, sad to say. :)


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Re: Charging iPhone on the road
« Reply #6 on: September 16, 2018, 11:29:18 AM »
Some devices are quite picky about their charging circuits.  And Apple products are well known to be quite picky.  My phone is not an apple, I am only reporting what I have heard.  I largely agree with Pavel on his comments that the Apple takes a few seconds to assess the charger and decide if it wants to accept a charge from that charger.  (Where Pavel says that is progress, I disagree, but I am not going to get drawn into an Apple vs non-Apple debate.)

I have a Garmin 64 GPS that is also quite picky.  It takes a few seconds to decide if it likes the charger, and it does not like dynohub powered chargers that lack a pass through battery.  To clarify, the Garmin 64 uses AA batteries or the Garmin branded proprietary battery pack that consists of two AA NiMH Low Discharge batteries.  The 64 has a button inside that is not pressed down by two AA batteries, but it is pressed down by the battery pack.  I put a bit of sheet steel inside the battery case over the button, that way a pair of AA batteries push down the button so that I can charge two AA NiMH batteries in my Garmin.

I have three charging systems on different bikes. 
 - The Luxos U will charge my Garmin.  That has a built in low capacity pass through battery.
 - The AXA Luxx 70 Plus will not charge my Garmin.  The GPS indicates that it is plugged in to a USB port, but the charge symbol is not shown.
 - The Sinewave Revolution.  (This probably is similar to your Sinewave.)  This will not charge the Garmin, it behaves like the AXA.

But, when I use a pass through battery, all of my chargers will work with my Garmin.

I was really disappointed with the Sinewave because I bought it for my Iceland trip.  I did not like the lack of waterproofing at the USB port on my AXA Luxx 70 Plus charger (and headlight) so I bought the Sinewave that has better waterproofing.  But because of the lack of built in pass through battery it did not charge some of my devices on my Iceland trip. And as a result I was often plugging into an outlet at night if I could find one.  (In all fairness, the AXA suffers the same problem so if I had not bought the Sinewave, I would have had the same problem with my other charger.  My disappointment was in buying something that expensive that did not meet my needs.)  But, having a good pass through battery has solved that for me.

This website describes the function of the pass through battery.

But you are lucky in one way, that website used to promote a specific brand of pass through batteries.  I bought several.  They did not work with my Garmin.  So, I have a bunch of small powerbanks sitting in storage that will probably be handed out as christmas presents.  I say you are lucky because that website no longer promotes the brand that they convinced me to buy.

If I recall, Dan has experience with pass through batteries too, but I do not recall the exact details.

The pass through batteries that I use (there are three) are no longer made or sold.  One is an unbranded solar powered small power bank from China.  One is a Brunton Ember 2800 solar powered powerbank.  And one is a Steripen branded solar powered powerbank.  If you see a trend here, I see it too, I think that the solar powered power banks are wired to accept a charge to the battery at the same time they are providing power to a device from the battery.  Other power banks I have tried will not both accept power while they are also sending power to a device.

One other possibility is to buy a big powerbank, one that will charge your phone several times.  It appears that John S. uses this method.  When riding you charge that power bank from your bike, then charge your phone or other devices from that powerbank at night.  That is less efficient, some of the electricity is lost as heat in the battery or other circuits, but charging and later discharging the big powerbank has worked for some riders that use Apples.  And this option has the advantage that if you do not ride for a day, the big powerbank is big enough to provide an extra day of power.

A year and a half ago I did a two week tour and was self sufficient for power, the pass through battery is what worked for me.  But, on that trip I used a pass through battery that no longer functions, it was a cheap Chinese unbranded low capacity powerbank.  If the three that I am now down to stop functioning, I will have to go shopping again.

When I ride on a tour, my phone is off or in airplane mode, wifi off and no apps running, my GPS (the Garmin cited above) is turned on and it might be charging.  If my Garmin is not charging, then I am charging something else. One or two of my cameras would be off but handy.  And usually I have one or two AAA powered taillights flashing while riding in daytime, I have some AAA to AA adapters that allow me to charge my AAA batteries in a AA NiMH battery charger.  My headlamp (for my head in campsite) is either AA or AAA powered too.

A side note, you did not mention if you use any AA or AAA batteries.  Dan recommends Eneloop batteries.  I have also had good luck with Eneloop but I have recently switched to Ikea Ladda NiMH batteries.  Ikea sells two varieties, the Ladda ones are white and cost more.  Still using my old Eneloops, but am not buying any more.

Another side note, for years I was using dynohub headlight and USB charger, but was using battery powered taillights because (1) I like having a taillight that is on while I am charging batteries with my USB port, and (2) in daytime I like my taillight to flash and the dynohub powered taillights do not flash.  But, I am slowly accumulating dyno powered taillights, but they are supplementing, not replacing the battery taillights.

« Last Edit: September 16, 2018, 11:31:14 AM by mickeg »