Weight Weenies

Thanks for the write up, much appreciated.

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@ToffieBoi

Sorry for the late reply to this, I've been very busy lately and haven't been able to check into WW.

So what's happening with your battery is basically a battery failure due to age, not necessarily the firmware or the device. When Li-Ion batteries die or get old towards failure, they will often give incorrect power outputs that are read by the device as 100% (even though this isn't the case). When I was researching this battery replacement thing, reading up on Li-Ion batteries and so forth, I did read about this occurrence. A similar thing happened with my laptop when the battery was past age.

As for re-calibrating battery settings on the Garmin? Nope, not necessary, it's been working fabulously.
I really wish a total expert in electricity/power/batteries would chime in here, but from what I understand despite the new battery having slightly less capacity compared to original, it is also operating at a slightly lower power, therefore it will be able to power the Garmin with the same battery life as the original. The Garmin hasn't shown any weaknesses or decrease in functionality operating at the slightly lower power... it's almost as if Garmin could have initially powered the unit with a lower power battery from the start.

Your new battery has less stored energy than original Garmin battery 600mAh vs 700mAh so you should expect shorter battery life if those numbers are accurate.

Your Garmin should be operating at the same power as before since power in DC circuit is calculated from voltage (which is the same 3,7V on both batteries) and current (current is as high as garmins circuit "demands" it and in this case battery isn't a limiting factor).

Lets say that Garmin has a constant current drain of 50mA. With 700mAh battery that would result in 14h of runtime and with 600mAh battery it would be 12 hours.
Power that garmin operates at would in both cases be 50mA*3,7V=0,185W.

Perfect! Thanks for the clarification zazo!!

A quick and short update on how the battery is working out since my change... in a phrase? Better than expected!

The battery has been holding charge really well. For example a few weekends ago I did a double along with a friend, but we really took our time (and called it a 'spa day'). Total time was 13hrs and 20 minutes (estimated), rolling time something like 10:30hrs. The week immediately following I was unable to go out for a ride, so I did not use nor charge the Garmin until the following Saturday when I went out on a short/easy 100mi w/ 9500' climbing. When I started up the Garmin again that Saturday morning it showed 43% charge left! And it lasted throughout the full 100mi ride.

So... not too bad, not too bad at all.

question if im just switching guts from 1 case to another, do i need to solder anything ?

recently got a new front and rear for my edge 500

excellent DIY write up. i would suspect that the battery swap would be the same for the Edge 800 as well.

did you get a chance to weigh the batteries? must be a difference if you're going from 700 to 600. it is WW after all.

@nathan

Only if you want to move the speaker. Everything else is pop-in and does not need soldering.


@kode54

I'm very embarrassed to say I did not weigh the batteries! I do have the old battery with me as I collect old hazardous waste to drop off at a local collection center. I will weigh the old battery this evening and see if I can track down the weight of the new one.

prendrefeu wrote:@nathan

Only if you want to move the speaker. Everything else is pop-in and does not need soldering.


@kode54

I'm very embarrassed to say I did not weigh the batteries! I do have the old battery with me as I collect old hazardous waste to drop off at a local collection center. I will weigh the old battery this evening and see if I can track down the weight of the new one.

so i'd just need to reglue (hold down) the speaker? if so, SWEET! project tonight!

New weight of the Garmin 500 = 55.6g (according to my scale)
Old weight, per online search, 56.7g verified.

So I saved 1.1g with the battery change.

Excellent! At $25/gram that's hardly the most expensive weight savings reported on this forum.

Thanks for the write-up! I never realized this was an option.

yea it was easy!!!! thanks for the original guide!

zazo wrote:Your new battery has less stored energy than original Garmin battery 600mAh vs 700mAh so you should expect shorter battery life if those numbers are accurate.

I remember seeing, or at least I think I remember seeing, a replacement battery that was a higher mA-hr rating than the original somewhere, but I couldn't find it again when looking. If anyone finds one, please post a link here.

Appreciated for the information.

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I found this very useful when replacing my Edge 500 back cover, to fix an Enter button that had cracked up.

The only extra trick I had to work out was how to remove the speaker. I tried just picking out the glue around
the edges of the speaker, but it still wouldn't budge. So then I used a 3 ml hypodermic syringe to squirt about
0.5 ml of acetone around the edge of the speaker. After 30 seconds, I could then slowly prise it up with
a bent-nose tweezer.

To reinstall the speaker, I used some silicone sealant, dabbed just around the edges of the speaker to mimic the
pattern used previously.

Cheers