Have Garmin 500 edge
Doing relentless 24looks like I’ll need to charge during the race
Anyone any experience of this?

Run a small cache battery plugged into it – works fine – no charging required.

Anker 3300 mah and a short lead. After 10 hours grab it and plug it in. Should charge your garmin in one lap.

See you there 🙂

Yes.

Due to the way the 500 is wired up you need a power source that has a built in earth or something like that. So if you plug in a normal power pack / charger thingy it stops recording and goes into charge mode only.

I bought a Garmin Power Monkey off ebay for £25 2nd hand. It has the requisite wiring in its connector.

Battery life wise I started Mayhem solo with it connected and turned on, to ease faffing. It (the monkey) was still on 1/4 charge after 16 hours. During a longer pitstop I disconnected it and ran the 500 for the remainder of the 24hrs. The 500 had 75% battery left after 24 hours.

So a different Garmin would let you plug in for a lap or so and would have enough charge to finish?

Not sure how I could mount the battery lead as have Garmin mounted on stem and would be difficult to feed wire in.

With one which only needed a lap to charge I could stick it in a pocket for a lap I guess

Main worry is that I run out of power before the Garmin!

Edge 500 will charge with a USB On The Go cable, which you can make for under a fiver from amazon. You need a USB mini to female, and a male to male adaptor.

The anker batteries are tiny. Electrical tape it to your stem or top tube.

As above. Anker battery straps or Electrics tape. Otg cable 90deg versions sometimes easier. Be really careful if wet as with the post open you risk killing it. Killed an 800 that way.

Main worry is how to attach the cabling and battery

Any show me their set up?

EDIT ah, yes, the modern Garmins stop when you plug them in.. my advice only applies to older ones.

I have an Edge Touring which goes into data transfer mode when you plug it in. However making a power only cable worked when I tried it just now. The device doesn’t show it’s charging, but the battery percentage goes up.

Took all of 3 mins to do.

As Jonba said, make sure you have some way of keeping Garmin and backup battery dry whilst charging.

Also, have you a strategy for ride/rest yet?
As per Relentless thread, unless you are planning a top20 finish you are probably going to be spending at least a couple of hours in the pits resting/eating, so you could just consider plugging in the external pack whilst stopped – saves you worrying about an on-bike setup.

I use tape. Bit of innertube to pad out then tape the battery to the top tube or under the stem. Pretty much how you’d do a bike light.

One other thing I thought of is that my 800 won’t record reliably for 24h. Personally I’d save the ride and reset it after 6-8 hours. Had this issue on a recent long road ride where it crashed at about 20 hours and I lost everything. Managed to do a soft

indeed, my 800 crashed at ~12.5hrs last year fortunately I noticed quite quickly and managed to save activity and start a new one.

EDIT ah, yes, the modern Garmins stop when you plug them in.. my advice only applies to older ones.

No they don’t, the 500 does, but that’s two generations old now! No such issues with the 810/1000/520.

Main worry is how to attach the cabling and battery

Any show me their set up?

I just used a load of Gorilla tape having wrapped the battery in cling film to keep it dry, doesn’t need to be anything special. It’s taped under the stem (purple cable – it was mrs njee20’s battery!).

Why bother making a lead and then buying a battery pack when the proper garmin external battery inc chargers, solar panel etc can be had for £25?

Cos you can easily modify an old lead for nothing and buy a battery pack for £10, that’s why. No need to pay 2.5x more.

USB OTG cable for £2.79. Add to any external battery pack. I imagine Ali Express have them even cheaper.

Is a newer garmin. More likely to reliably record for 24 hours?

Watches thread…
I’ve just got my dynamo working on my tripster, so will need to see if the USB out from my light causes the garmin to go into data mode or not.
I also need a right angle connector, which I’ve ordered as space behind the gps is tight!

DrP

Is a newer garmin. More likely to reliably record for 24 hours?

I lost all six hours of the big dog but kept the 12hrs of the Pivot 12hr on my Edge 810.

Like most Garmin experiences, it’s ‘unpredictable’. 🙄

Though the 800 is meant to be the most stable, i do believe….

It’s also owned by the coolest dudes this side of trendsville…

DrP

Just looking an excuse to upgrade!

I’ve done a 24 hour ride with my 1000 and it was faultless. Was navigating too.

Sample of 1 not necessarily the most reliable!

Lol
Navigating?
You sitting on back of a tandem?

No… I had a route on the screen and it was providing turn by turn directions. What would you call that? 😕