Garmin 705 Extending Battery life

[Cyclops]

You could always make your own charger.

I made a charger for my Edge 305 following the instructions here and it worked fine. I just enclosed the battery holder in a zip lock bag and attached it to the underside of the stem with zipties. This seemed sufficient protection even in the most extreme of downpours.

[Greenbank]

I think the problem with the Tri Bag is cable length.

This photo makes it look possible if the battery pack is placed in the tri-bag so the cable is sneaking out of the top/front.

This is the 'new' battery holder, resting on the top tube for the photo

[LiamFitz]

It's turned up, so now testing it.

The unit doesn't go into computer mode when connected as I feared.  I think I'll need to work out whether I use it either:
a) From the start and let the unit run itself down
b) Use the internal battery and then switch on the external source around 200k...

Ever noticed that you never have any batteries in the house when you need them?  Or is that something to do with having kids?

Liam

[Jaded]

Well my first test in anger will be tomorrow night, on the Ride from Oxford to London. Except my ride starts 50 miles further away at home. I'm going to set out with the GPS powered by the AA pack, see how far I get on that, and aim to switch to internal when the AAs give up. The battery pack will be in my rack bag, and I'll take a spare set of AAs along just in case.

[Jaded]

The AAs lasted from 17:15 to 06:40. With the minimum or next to minimum back-light on. They were still going, so I don't know how long they'd last altogether.

[LiamFitz]

Worked quite well on Saturday.  Ran on normal power until the 200K mark and plugged in the battery pack.  Ran clearly with that from around 5.30 pm to 11.30 when I finished.

Mounted the pack in an old wash bag (ex BA Executive Club don't y'know) and three zip ties to secure it.  Because the lead comes out of the bag next to the head the bag ended up at an angle to accomodate the cable feeding out of the bag and around the headset so an adjustment might be in order next time.  A couple of extra CM in the cable would have been useful.

Thanks for the advice everyone.

Liam

[MattH]

I've been using one of the longer style boxes for ages. Mine has a very thin coiled cable, which eventually started to fray badly where it exited the battery box.
Simple solution - chop up a standard USB cable and solder it in.

This is where I found something interesting: the original cable had the unused pin next to the ground on the USB connector grounded, whereas my cable only had four wires (and nothing to the unused pin).

Pin 1 - VBUS
Pin 2 - D-
Pin 3 - D+
Pin 4 - unconnected
Pin 5 - GND

Pin 1 - VBUS
Pin 2 - D-
Pin 3 - D+
Pin 4 - connected to pin 5
Pin 5 - GND


Running with pin 4 unconnected, the 705 goes into computer mode. Running with that pin grounded, it works as normal (and charges from the external power).

[MattH]

As a follow-up, I've had a bit more time to look into this and have now played with a powermonkey and a couple of tips (kindly sent to me by the very nice people at Powertraveller), you can get by with just a four pin cable. You have to tie the two data wires together - so you get
Pin1 - VBUS  (+5v)
pin2 - connected to pin3
pin3 - connected to pin2
pin4 - unconnected
pin5 - GND

This also means that you can control the 705 saving out its data to the file system. I don't know if the problem has been fixed yet in the firmware, but certainly early versions could run out of memory during a long (600k) ride, and start to drop the early data points as the buffer looped around - even if there is plenty of space available in the internal file system and/or memory card. Going into connected mode means it saves the ride out to file system, so you should never run out of memory (unless doing a world tour).

Now that I (think I) really understand what is happening, I can put a switch onto my battery box to change the mode that the 705 runs in, to allow putting the ride into long term storage if it starts to run out of space.

I should get the chance to find out if the running-out-of-memory issue has been fixed in firmware yet on the Elenith - as I intend riding there and back, bringing the total to close to 700K. V2.30 says "Removed time limitation from history recording." in the release notes, but I don't know if this is the same thing. On my long rides after I lost part of the "Bridge too Far" 600K I've had a stop somewhere where I could briefly plug into a computer to avoid this altogether.

[frankly frankie]

I should get the chance to find out if the running-out-of-memory issue has been fixed in firmware yet on the Elenith - as I intend riding there and back, bringing the total to close to 700K. V2.30 says "Removed time limitation from history recording."  On my long rides after I lost part of the "Bridge too Far" 600K I've had a stop somewhere where I could briefly plug into a computer to avoid this altogether.

It sems to be more of a 'feature' than an 'issue'. 

I'm not familiar with the Edge models but in the manual doesn't it say something about resetting the timer periodically to avoid overwriting the history data?  Every 4h if you're recording once per second, or every 12h in default mode.

The Etrexes have a known limit of 10,000 track points and at default settings you'd be likely to hit this limit sometime after 500km, however if recording the daily log to card as well I don't think this limit even applies (and if it does your ride is split over 2 days anyway).

[straying OT] Incidentally I experimented over Easter with the Etrex recording interval settings - leaving the 'method' on 'Auto' (which I quite like) but raising the 'interval' from 'Normal' to 'More Often' results in approximately 50% more points being used.  So a recorded track that consisted of about 400 points in 'Normal' mode now consists of about 600 points.
Raising the setting to 'Most Often' doesn't make very much difference - maybe another 15% - so the 600 points goes up to about 680 or so.  At this rate the 10,000 point limit would be reached at about 300km or maybe slightly before.

[andrew_s]

The Etrexes have a known limit of 10,000 track points and at default settings you'd be likely to hit this limit sometime after 500km, however if recording the daily log to card as well I don't think this limit even applies (and if it does your ride is split over 2 days anyway).

The 10,000 point limit doesn't apply to data logged to the card. I've done a lot of rides at 1 point per second, where 10,000s is only 2h 47m. You get all points logged to the card, and if you ride back close to your outward track on the return journey, you can see the expired points dropping off the start end of your track.
(60CSx, but that's mostly the same as an Etrex)

[frankly frankie]

As a follow-up, I've had a bit more time to look into this and have now played with a powermonkey and a couple of tips (kindly sent to me by the very nice people at Powertraveller), you can get by with just a four pin cable. You have to tie the two data wires together - so you get
Pin1 - VBUS  (+5v)
pin2 - connected to pin3
pin3 - connected to pin2
pin4 - unconnected
pin5 - GND

I think an Arrivee 'how to' article on this subject would be really appreciated Matt. 
Probably past the deadline for LEL, unfortunately.

[yello]

My Gomadic has recently developed a frustrating problem. I've so far only used it to recharge (rather than run) my Edge 305, and I recharge the Edge whilst it's off. It was all working fine but now has become a bit erratic.

Sometimes, I plug it into the Edge, switch the Gomadic on and the Edge powers up too. Other times, it behaves, the 'Battery Charge in Process' displays all fine and dandy like it should... but only for a few minutes, then the message disappears but the Edge hasn't recharged. First time it happened I thought the AAs were dead so changed them, but the same thing happened.   If I leave it all for a couple of hours, same AAs in the Gomadic, and try again it's fine.

Anybody got any ideas?

Thankfully, I have a few months before LEL to resolve this but I don't know whether to play safe and look at alternative recharging solutions rather than risk it.

EDIT:  Credit to Gomadic. I emailed their support with this problem and they've said it sounds like a problem so they are going to replace it for me AND with a unit that takes rechargeables. Fingers crossed that the new one works!   

[aidan.f]

Why not pack your mains charger & sneakily plug it in when sitting in the cafe.....but if there is only one socket free I thought of it first!

Quite a bit of charge can be had in 15 mins.

P.S. the edge 205 can be supported happily from 4 AA ni-cads for about 6 hours, then it's own internal battery takes over  no need for complicated regulators.

[LiamFitz]

Came across this little challenge on BCM this weekend....

Twice, whilst attached to the Gomdaic, the Edge 705 stopped and the screen showed a picture of a white battery - I assume this was because there was no longer enough juice in the Duracels.  On both occasions I ignored it (firstly because I had some new batteries in my drop bag which was about 45 minutes away and secondly because I was within half an hour of the finish).

However, today when I came to review my heroic climbing and vast distances covered...there was no trace!

I can't seem to find an answer anywhere, but do we think it's a safe assumption that because I let the thing die nothing was saved and was therefore purged?

Answers on a postcard?

[delthebike]

Answers on a postcard?

The white battery image is a PC tower. I think your 705 decided that it had become connected to a PC and tried to download to it but didn't save the history. Maybe the files are there in the folders?

P.S. the edge 205 can be supported happily from 4 AA ni-cads for about 6 hours, then it's own internal battery takes over  no need for complicated regulators.

More like 20-30 hours.

[LiamFitz]

Answers on a postcard?

The white battery image is a PC tower. I think your 705 decided that it had become connected to a PC and tried to download to it but didn't save the history. Maybe the files are there in the folders?

Sadly not there in old history files... lesson leant. 

[delthebike]

Sadly not there in old history files... lesson leant. 

Do you have the basic info on the history screen. Time, distance, speed avg/max etc?

[LiamFitz]

Not a sausage - the last mentions are of a training ride last week and some fiddling this morning!

[Manotea]

However, today when I came to review my heroic climbing and vast distances covered...there was no trace!

Funny you should mention this. The tracks on my eTrex have gone missing. That would be because the 'record tracks' setting has mysteriously changed to 'no'! I'm heartbroken, especially as the Trip Odom is showing 653km...

[Greenbank]

However, today when I came to review my heroic climbing and vast distances covered...there was no trace!

Funny you should mention this. The tracks on my eTrex have gone missing. That would be because the 'record tracks' setting has mysteriously changed to 'no'! I'm heartbroken, especially as the Trip Odom is showing 653km...

I had exactly that on The Dean. I can't ever imagine why I'd ever choose to set it to "no" so I'm guessing it was some ham-fisted/fat-fingered mistake by me. Got to the end and went to check whether I'd used up all of the track memory (still had 14km to go to get to the Travelodge in Wheatley) and found I'd used 0% of track memory.

Annoying as I wanted to check where I'd been slower/faster than the year before.

I now check the settings before starting (or when it's been turned off) and make periodic checks during the ride that the track is being laid on the map page.

[frankly frankie]

(Makes note to self to check this setting periodically)

... and make periodic checks during the ride that the track is being laid on the map page.

... but what you see on the map page is the 'Active Log' which sits in memory - not the log on the SD card

[Greenbank]

(Makes note to self to check this setting periodically)

... and make periodic checks during the ride that the track is being laid on the map page.

... but what you see on the map page is the 'Active Log' which sits in memory - not the log on the SD card

SD card?

[delthebike]

SD card?

Some modern GPS devices have SD cards, or microSD cards, to record data. The ancient thing you have, GB, has little people with chalk and slate inside. 

[MattH]

Answers on a postcard?

The white battery image is a PC tower. I think your 705 decided that it had become connected to a PC and tried to download to it but didn't save the history. Maybe the files are there in the folders?

Sadly not there in old history files... lesson leant. 

I assume you've actually looked on the device itself using a file app to see if the tcx exists?
I've had a couple of annoying times (including BCM) where a crash causes a corrupt tcx - which then is ignored by Garmin's software. You can retrieve the data by copying the file out and manually correcting the xml, but it is more of a pain in the arse than riding 600km.

[yello]

I assume this was because there was no longer enough juice in the Duracels.

I think I may have a similar problem.

The replacement unit Gomadic sent me does the same thing as the first one did; i.e. does not fully recharge the Edge. It either turns the Edge on and/or just stops charging. But at least with it taking rechargeables it is easier to experiment.

On measuring them with my multi-meter, it appears that once the batteries drop below a certain point, they Gomadic stops charging. If I turn the Gomadic off and on again, it turns the Edge on. The Edge registers that there is an external power source but whether it's using it/charging, who knows?

Caveat: I don't really know what I'm saying/doing here BUT one of my fully charged rechargeables measures around 1.43 volts. The Gomadic stopped charging and the level was 1.34 volts. A similarly 'used' alkaline measured 1.29 volts.

Gomadic reckon 4 to 5 charges out of a set of alkalines... but there's no way I'd get that. One set would not fully charge the Edge if it were discharged! So it's going to make LEL a battery-fest for me! I'm either going to have to take a stash of charged up rechargeables OR buy new alkalines as needed then possibly carry them around in their semi-depleted state to use later at home.  I guesstimate around 20 batteries would see me through!

Can one of you folks who have a Gomadic comment? I'd be interested to see what results you might have gotten.