Your Garmin help, please

Had a bit of a look into this as my rides are starting to outlast my garmin battery. It's 4 years old and I like using the maps screen and having my HR, cadence and speed sensors connected.

Some good info here: https://forums.garmin.com/showthread.php?33752-Edge-800-Replacing-Battery-Pics-and-some-info-not-complete-yet

Seems that replacement batteries are available readily, just search on Amazon etc. However, virtually all the available replacement batteries listed as Garmin 800 compatible are 1000mAh whereas the original is 1100mAh.

I did a little more digging and found this page which suggests that the Nuvi batteries are compatible with the Edge 800 and are available in higher capacities (1200mAh+): http://hqrp.com/hqrp-1200mah-battery-for-garmin-nuvi-1200-2200-2300-2400-2500-2700-3400-3700-series.html

I am going to keep searching and see what the highest capacity Nuvi battery is.......

Have taken a punt on one of these: https://www.powershopuk.com/Batteries-GPS-Sat-Nav-Garmin-Garmin-361-00035-03-Replacement-Battery-High-Capacity-1200mAh.html

Just a question on whether it fits. Seems like the space inside the 800 can be increased with a dremel quite easily....

UPDATE 1: Replaced my Garmin 800 battery last night with the 1200mAh version from the link above. Took 30mins. You need small torx T5, small flat bladed screwdriver, tweezers and a little double sided tape to secure the new battery down.

I used the instructions in the garmin forums thread ^^ and would add a couple of points:

1. Once you have removed the 6 torx screws, the top lid comes off and remains attached to the main unit by a ribbon cable. Be careful when disconnecting the cable. I pulled at the connector at a certain angle thinking that was the way is unplugged. It didn't come away and I tried again at a different angle and it was easy. I could have caused some damage had I carried on pulling at the original angle.

2. Once you have removed the silver torx screws that secure the screen to the main circuit board, get a small screwdriver or tweezers and lever the board away from the garmin body. A small pull should do it. It is connected to the body by a small oblong connector.

3. With the garmin flat on the desk, to remove the old battery pull the connector straight up away from the garmin body (towards ceiling), not by yanking the cables across ways (towards wall).

4. The old battery is stuck down with some tenacious double sided tape. Get a screwdriver under the edge and lever it upwards. It will eventually free.

5. Only handle the edges of the circuit board. Don't go touching the components and soldering, you may damage it with static.

6. When placing the main circuit board back into the garmin body, just line it up and push straight down to reconnect the oblong connector between the garmin body and the main circuit board. Also, make sure the on/off switch lines up. It should be no problem but you'll have to re-open the garmin again if it doesn't line up correctly.

^^ If this sounds complicated, it shouldn't. Take your time and it's pretty straight forwards.

Will report back on the new battery life......

UPDATE 2: New battery is great and has Garmin 800 can happily run for 7 hours plus on maps screen with HR sensor and GCS10 attached (After 7hours it still had approx. 30% remaining). Very happy. Here is picture of new battery label if you're interested, it's the one purchased from the link above:

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