Recording rides

[G-Zero]

I have a CatEye speedo that works off a magnet on the front wheel but I also record using Runkeeper on my iPhone.
It works very well and I like the interface. However, even though I turn off WiFi and Bluetooth and dim the display my now longer (to me) rides leave the battery in a very low condition. I know people use a Garmin device which I think links to Strava but how long does the Garmin battery last and can it link to Runkeeper or not?

I'm also using my iPhone to record my rides, however I use Strava rather than runkeeper and I've never had any problems with battery life.
It's an old iPhone 4, which I don't know is better or worse than the latest offerings when it comes to battery life, but my Bluetooth stays on 24/7 and I never switch anything off when riding.

I often do a scenic ride in to work (30 - 40 miles) rather than the direct 12 mile commute, stop or pause Strava, do up to a 12 hour shift using my phone as normal for calls, texts, emails etc, then use Strava for the 12 mile home run and always have sufficient power.

The only time I was concerned about the battery dying was when I did my first century ride with solid recording of 7+ hours, but when I got home I'm fairly certain I was down to 20% remaining.

 

[Globalti]

I just use my Cateye and record the ride data in an Excel sheet. That way I can compare average speeds over the same rides and see the proof that I'm still crap after 21 years of mountain biking and 6 years of road riding.

 

[Berk on a Bike]

When I put my phone into airplane mode a message pops up on screen saying, "surely you can't be serious" to which I reply, "I am serious and don't call me Shirley..."

 

[albion]

[QUOTE 3899414, member: 259"]Not any more - it works fine if you have a recent version of IOS, But I've given up on using a phone for bike rides (Apple or Android)., and like almost everyone else I use a Garmin.[/QUOTE]
Holy shoot you are right.

Apple have now officially announced it for IOS 8.3, not that Airplane mode ever had much to do with GPS.
https://support.apple.com/en-us/HT204234 8.3

 

[Domus]

It may save battery but it also stops it being a phone.

Looking at going Garmin

 

[Domus]

Garmin Edge Touring on order from Wiggle.

Will be back with even more questions when it arrives.

 

[Domus]

Delivered today, now updating maps. Taking f o r e v e r !!!

 

[Dogtrousers]

On the GPS/mobile data front ... most (all?) phones use A-GPS (Assisted GPS) which means that they do use the phone data connection as well as the satellite signals.

Getting a GPS fix requires downloading some data from the satellites and then, once you have the latest data, using the satellite transmissions to fix your position. This initial download is why GPS units take a while to "cold start" and get a position fix. A-GPS speeds things up a bit by doing the initial download over the phone network, giving you a quicker time to get an initial fix.

So, once you have your initial fix you shouldn't need the phone data connection. Theoretically you shouldn't even need your network connection to establish an initial position fix (but it will be much slower than if the data connection is there).

I'm no expert so that may not all be 100% correct ... but in short: Phones do use the phone data network in providing GPS services. Maybe not all the time, but they do use it.

 

[ianbarton]

The position of all the cell towers is known to a high degree of accuracy. The phone gets a bearing on all the towers it can see and can use this to triangulate its position. Depending on how many towers the phone can see, this data alone is enough to get your position within a few metres. Each cell tower has a unique ID, so the phone knows exactly which tower it is receiving a signal from.

Since Google Streetview captured the MAC address of any Wifi access points it could find, this can also help to find your position.

 

[Milkfloat]

A-GPS does not use any data allowance or call time, it is simple triangulation.

 

[Dogtrousers]

A-GPS does not use any data allowance or call time, it is simple triangulation.

No, A-GPS does use data services, that's the whole point of it. It assists time to first fix by dowloading the almanacs via packet services instead of from the satellites. It's not related to cell tower triangulation.

The wiki page is probably the most easily digested source of info.

I'm not claiming to be an expert on this, but my point here is that if you disable data services, and your phone uses A-GPS (which it almost certainly will) then time to first fix will be banjaxed. You may or may not be charged for data usage during A-GPS transfers, that's up to the network. My guess is that you will be charged. But that's just a guess.

As to trianguation from cell towers, I've never had any dealing with this, but it sounds very fishy to me, so I'm guessing. Phones can't get a bearing on the cell towers that they can "see". They aren't directional, they only know the relative signal strength. I do know that if the authorities are tracking you using this kind of method the results are very approximate. Nothing like CSI.

 

[Domus]

First ride out with the Garmin, recorded everything and seemed an accurate speedo. Uploaded to Garmin Connect when I got home. All seemed well. Then I had a play and uploaded to my Runkeeper via the plug in thing.
Now it seems my average speed was not 11.14 mph but 87 mph, milage was the same but it took 17 hours not the 2 hours I was out. Bizzarre.