A few notes about GPS tracking while out running. On my mobile phone (still Nexus 4) I used the app RunKeeper (the free version, not Pro) to record the runs. The data is then synced to other services like SmashRun (see below), Endomondo, and even Dropbox using tapiriik.com (a great service and well worth the few bucks for automated sync). Recently, I signed up on SmashRun (free version) for stats and the likes.
A couple of weeks ago I came across Runalyze which offers a lot of statistical data – completely free, no paid version. To me, it seems to be a bit overkill, though.
— Edit 12/02/2016 —
RunKeeper has been bought by Asics. It might be time to switch to the “last” independent running App – Strava (which is supported by tapiriik as well, by the way).
A few months ago, Holux released a new firmware for its M-241 GPS logger. This latest version v1.12 allows to turn off Bluetooth whereas before it was always on – whether used or not. Turning off BT is expected to lower the overall current consumption of the device. But does it really?
To find out more, Oliver and I set out to measure the power consumption. In theory, this is quite simple: Get your hands on a fairly accurate current meter (in our case a Fluke 87), put it in series to the power supply circuit and measure the current in various states.
I tested my Holux with rechargeable batteries from Ansmann and can report that they work fine (even on a winter day in the mountains). I’ve used the following type: Ansmann maxE 2100 mAh (it’s a NiMH HR6 with 1.2 V and 2100 mAh)
One problem I noticed though was that the battery diameter is too big meaning that you can get it in but not out again (at least not easily). Removing the wrapper helps. I don’t know whether the battery compartment is too narrow or the battery itself too wide. According to the AA specs, the diameter is supposed to be 14.0 +/- 0.5 mm.