Garmin Edge 800 Battery Replacement

I just replaced the battery and back case on my Garmin Edge 800 bike GPS, it was pretty easy and as long as you have the right tools you shouldn't have any trouble. Just make sure you have good lighting, and make sure the small screws don't roll away. You should also make sure you're not causing any static discharge - ground yourself if you're in a carpeted or dry environment.

You'll need a Torx T5 screwdriver and a plastic spudger (or just a plastic knife from any take-out meals you've had recently)

BE GENTLE with the screws, fingertip tight is plenty. They will strip easily if over-torqued.

Here's my Garmin Edge 800 and a new white back case with battery that I got off eBay



Remove the 6 Torx T5 screws around the edge of the Garmin



Now the front case and touch screen will come off. DO NOT PULL IT OFF YET - the touch screen is attached to the board below with a very short ribbon cable. Use your spudger or plastic knife and pop off the connector from the board below, then remove the front case & screen





Continued below....

Now, remove the 2x Torx T5 screws at the bottom of the screen



You can now shift the screen slightly to expose the post holes that the screen case sits in. Put your screwdriver in one of these empty holes (not a hole that a screw was in) and that should give you just enough leverage to pop the PCB board off the back case connector



Done! Now you have access to the battery, you can replace it or replace the entire back case.

PLEASE NOTE that if you're planning to replace the entire back case, the new battery/connectors board may not line up with your existing main board. I think this is because the two boards were connected and then glued into the back case at the factory, for resistance to moisture. If it doesn't line up, you'll have to cut away all the glue with an Xacto knife, a very tedious process.

If you're just replacing the battery though, there's no change in the way things line up so you can ignore that warning.



Assembly is, as they say, the reverse of disassembly. When reconnecting the main board to the back case board, it's helpful to flip the screen forward and press down on the area covered by the barcode. Very little force should be required for the connector to pop into place.

Please note that if you want to replace the back case, that you pick the right one. There seem to be 2 variants out there. One with a 10mm distance to the lower end of the case and 1 with 8mm distance. It's the part above the USB connector that makes the difference. If you pick the wrong one, it won't fit. This results in no connection between the battery and the main PCB.

There seems to be a visible difference. The '8mm' has 3 circles (left to right) on that part and the '10mm' seems to have just one and a square above.

Thanks, that's really useful information and probably explains why my my replacement back case didn't fit.

Could you point out the 3 circles vs 1 circle with square area on the photo below? Not quite clear on where I should be looking.

I attached a zoomed crop of one of the photos above, since the white & blue back cases/battery PCBs don't seem to be compatible, the markings should be different.

The only obvious difference I can see, is that one PCB is labelled 94V-0_331-2 and the other just 94V-0. Some of the other numbers look different too (top right) but are covered by the black caulking on that model. Maybe the clear vs black glue is a sign as well...

Thanks,
Skye

I'm not sure about this, it's just a first conclusion for now. I don't have all kinds of cases lying around to prove a pattern. I also don't know if there is a difference between the black/white and black/blue version. All I know is that the Edge 810 has the 10mm version of the case. It seems that the 10mm one is the newest of the two.

My Garmin has a version 2 main PCB and is in a 8mm version and I have had a version 3 PCB, which needed the 10mm case. That might help figuring things out.

On the pictures I have shown you where to look for the marks. It's not solid that it works like this, but it's a start. the distance from that bit of the case should be 8 or 10mm from top to the inner side of the case below (along the line on the black/white case on the picture).



Edited 1 time(s). Last edit at 01/27/2016 05:03AM by RJC88.

Brilliant thank you again for circling that.

Here's another picture with some info on this. I got this from eBay, where a seller points out this difference. It confirms my thoughts on the circles and square. On the outside there are no signs of this change.

Also the case seems to be the same (on the outside) for Edge 800/810 and Touring (plus). The Edge 810 has the 10mm case. The 800 has two sizes.

I will have to change a USB/SD board to another case, because it doesn't fit. The other case has a non working SD card reader. I hope I can get it water resistant again after that. I will report back on that, if you like.

That does confirm the theory, thanks. I would be curious to hear how the USB/SD board swap goes, I started trying to pick away at the glue/sealant on my white case to do that myself, but I got bored and gave up...

So As I need to replace my edge 800 case (the tabs cracked and one broke off) is there any way for looking at the unit from the outside to the the difference? I presume not? Mine is a black/white case and a 2013 model as I have managed to get a case off eBay a white one I remember when these 800's were released so don't know if mines an older model so would that be the 8mm or 10mm many thanks for your advice

There's probably a way of telling from the serial number, but I have no idea what that would be. The only method I know of is the one that RJ described above, which requires disassembly.

Just curious, how did the quarter-turn mount tabs break off? Crash your bike?

Skye

Quote
Ant
So As I need to replace my edge 800 case (the tabs cracked and one broke off) is there any way for looking at the unit from the outside to the the difference? I presume not? Mine is a black/white case and a 2013 model as I have managed to get a case off eBay a white one I remember when these 800's were released so don't know if mines an older model so would that be the 8mm or 10mm many thanks for your advice

I Dropped the unit when I was gathering up my cycle gear after a ride But was very surprised that on looking at it after It looked, it was only the next time I was out on the bike the I noticed it jumping around in the mount so then I saw the damage I just got another case with the battery and the calked in memory card and usb unit I just need to take the back case off my unit to see if the cases are compatible and if so that I perhaps can just change the pcb and screen over an d it might work though as bought the other back case off ebay feel sure that knowing my luck I will have to take the M/card and usb circuit out and put mine in which as you say will be a labour-some task I will just post a pic of the back case I bought all I have to do now is see if it works!

Well after taking my unit apart I find that mine is a 10mm case so the one I purchased will be no good as its been said the pcb won't locate on to the battery pcb so I think that rather than get another one all be it a 10mm case I would still have cut all the calking out the fit my usb and memory card unit in place in the new case so I will get on of those glue on mounts as they seem very popular heres my own 800 edge and its same colour but still a 10mm case so even if you were able to get the USB/SD PCB unit out from all that calking they wouldn't change over, still its a good job I am able to return it



Edited 1 time(s). Last edit at 08/05/2016 01:14PM by Ant.

Good point, there is a good chance the PCB is a different size, although it might just be a different offset. It's a lot of work removing all that caulking so I'm not going to check any time soon. I just checked my spare case and it's also a 10mm or I would have offered to sell it to you for cheap ;)

Skye

Hi Well that was really a kind offer but as I said I have got a new mount from a company here in the UK and have used expoxy resin to fix it on to the broken one it lifts the unit up a little but is a solid job and stays in place firmly. so I'm well chuffed!

You mean the Dog Ears solution? Never tried it, but seen it on some devices. I don't think it's a good solution, since it it a weak connection to the case and puts a lot of strain on a small area. This on the part that has to endure a lot during a ride.

I have not found any relation between serial no. and type of case.

I found out that removing the USB/SD board was easy. Just remove the sealant and pop it out with a needle. Replacing it wouldn't be such a hard thing to do. I never had to place it back and make the case water resistant again, so that is still a thing to figure out.