Battery lifetime

Hard to say. In general terms batteries such as these are typically rated for 300-500 charge cycles before capacity drops below 75-80%, but I have no idea of the specifics for these batteries.

Charging to 100% and leaving it stewing for hours like that is bad. So is complete discharge. Heat is also the enemy of long life.

FWIW I charge my 6X Pro Solar to 80% once per week and it is down to about 30% a week later, so I put it through 1/2 a charge cycle per week, or 26 full cycles per year. I can expect several years service on that basis.

For others who chew through the batteries faster, for whatever reason, or charge without sympathy for the battery chemistry, the life expectancy will be less.

It is the same for phones, laptops, electric vehicles etc etc. 

That’s a good question. I do not have an F6, but a Marq and an F5. I bought the F5 in March 2017, and used it daily for 2,5 years when I got the Marq. But I still use the F5 regularly, keeping it charged. Often charging to full or almost full from 20-30% battery. I recently tested the capacity of the F5 by placing it outdoors and starting a GPS session (no BT connection not OHR, since both I and my phone would be elsewhere during the test). The F5 ran 23:57:31 before closing down. The spec is “up to 24 hours”.

I think that is good for a 4.5 year old Fenix, and assuming similar or near similar batteries for the F6, perceived battery deterioration is perhaps more related to the software and how it uses the CPU.

Of course, this is just one (my) single use case.

eezytiger said:

Hard to say. In general terms batteries such as these are typically rated for 300-500 charge cycles before capacity drops below 75-80%, but I have no idea of the specifics for these batteries.

Charging to 100% and leaving it stewing for hours like that is bad. So is complete discharge. Heat is also the enemy of long life.

FWIW I charge my 6X Pro Solar to 80% once per week and it is down to about 30% a week later, so I put it through 1/2 a charge cycle per week, or 25 full cycles per year. I can expect several years service on that basis.

Yeah, for a device with a near daily charge cycle (most phones, and many smart watches) you can reach this 300-500 cycle point in 12-18 months. But given the fantastically long run times for the Fenix 6, most people report a charge cycle of around a week - so reaching that point is going to be 5+ years.

With my 6s Sapphire I need to charge it every day (mostly during the shower) or with the amount of activity I record it would barely last 3-4 days. Or maybe 2-3 during summer with longer hikes.

I guess the battery will die after we'll decide to switch to a newer version or another manufacturer.

My last watch was a 245, had it for 2 years and once the battery was not working so well I asked garmin support how much a new battery would cost. They swapped me for a new one basically for free. Either you send your watch in and then wait to get the new one, or pay the price of the watch and get it immediately and send yours in after the new on is received and get refunded, I did the latter. It was awesome, I intend to do the same with this watch. 

p.s. I have a Philips lithium ion shaver that I've owned for 18+ years and is still going strong. It is the 007 shaver featured in Die Another Day (released in 2002). Not sure exactly when I bought it, but my Amazon review (written in 2016) implies 18+ years ago. www.007museum.com/Philishave_HQ8894.htm

I shave daily and charge it less than once per month. So lithium ion batteries can last a very long time when charged infrequently. 

I sold my Fenix 3 to a friend of my son. The watch is 5 years old, he uses it regularly and battery life is still good. So I think if the watches are treated well (avoid unnecessary frequent charging, no storage with empty battery etc.) they should last very long.

I charge my 6X Pro Solar when it gets down to about 80%, less chance of battery getting warm/hot compared to charging when it gets below 20%.

Replying to myself, here is an article to support what I said above....

cleantechnica.com/.../

I see many users very happy with their Fenix 3!

This is a good sign!