235 battery life - post your experience!

Hello everybody. Besides the issues or ways of use our Garmins Fenix 2, do you know what are the best pratices about the charging process, to allow us to extend the battery life? For instance: what's the minimum % we need to start the charging? Do we need to get closer the 0%? More: do we need to perform always a full charge (or is it better to stop in a specifc % of charge)?

Thanks a lot
Trajano (Brazil)

As with any lithium battery the rules pretty simple, in that the watch electonices will take care of everything. Charge when you like it won't affect capacity or cycles. Only a few things you need to watch:

Dont charge when very cold, close to freezing.
Don't let the watch run flat and store for a long period, the voltage could drop to a point it damages it.
Don't fully charge the watch and store for a long period as it will adversly effect capacity.

My experience so far.

When my watch arrived it the battery was completely flat, which I wasn't expecting. I put it on the charger and gave it a full charge. I took off the charger at about 5:30pm Friday.

After charging I started using it as my activity tracker with the 24/7 HR on and on Saturday I used it for 2 activities using GPS & HR, a ~20min bike ride and a 40min run. By 6:00pm Saturday it was down to about 53% charge remaining and since I was planning on a long run on Sunday I didn't want to risk running out of battery so I charged it to full again.

Rain and a head cold moving into my chest meant there was no long run outside on Sunday, but I did do an 1:15min run on the treadmill and as of right now at 8:19am Monday I'm at 62% charge. I seem to be getting better life out of the 2nd charge although I did an activity that lasted a little bit longer than the 2 on the first charge there wasn't any GPS activity but it was still running the HRM full time for over an hour.

We'll see how it does in the future.

With the app "battery Gauge" from Connect IQ, you can see how match battery was consumed in the last 24 hours.
I have ~20% in 24 Hours with Activity Tracking, Smartphone notifications, and Optical HR sensor on, but WITHOUT GPS.
And ~1,6% in 24 Hours ONLY with activity tracking. NO GPS, No Heart Rate, no Bluetooth.
I hope I have helped you a little to have an idea about the battery.

With the app "battery Gauge" from Connect IQ, you can see how match battery was consumed in the last 24 hours.
I have ~20% in 24 Hours with Activity Tracking, Smartphone notifications, and Optical HR sensor on, but WITHOUT GPS.
And ~1,6% in 24 Hours ONLY with activity tracking. NO GPS, No Heart Rate, no Bluetooth.
I hope I have helped you a little to have an idea about the battery.

Interesting numbers. You only saw a 1.6% drop in 24 hours with step-count enabled? That seems impossibly efficient. If those numbers are correct, I wonder how much bluetooth is responsible for the extra 18.4% versus optical HR (especially given the excessive current drawn by the optical, a bug acknowledged by Garmin per DC).

I know it is a completely different watch but Bluetooth on my tomtom watch hammered the battery. I left it off and switched it on just to sync activities. And that wasn't even using it for notifications.
So it may well be bt that is using a lot of the battery.

I know it is a completely different watch but Bluetooth on my tomtom watch hammered the battery. I left it off and switched it on just to sync activities. And that wasn't even using it for notifications.
So it may well be bt that is using a lot of the battery.

Maybe it would be useful to have to have the option for Bluetooth to automatically switch off on certain day parts? E.g. over night? Still waiting for my watch but whatever device you have Bluetooth normally has a fairly major impact. It definitely does on my Smartphone and Garmin Edge 1000.
If I can get 4 days out of this with just the odd hour of GPS activity I will be happy. With the Microsoft band just getting 2 days and the Apple watch less than 24 hours 4 days would seem acceptable to me. I'm not sure how Garmin thought they were going to get 9 days from the 235.....

I received my watch on Friday, early afternoon, and it was 94% when I unboxed it so I didn't charge it to max. I had read Ray's review prior so I was figuring on having to charge it by now but I'm still sitting at 29% battery. I did about 45 minutes of "workout" time on Saturday with GPS & GLONASS but a cold has kept me from running since. I've used it pretty extensively as far as I consider as it's a new gadget. I've got bluetooth on full time syncing with my phone (25+ texts and tons of notifications coming through from various sports apps/games), 24/7 HR monitor, step/sleep tracker, etc. I'm guessing I'll get one more day out of it before it gets to 5-10% when I'll charge it. I typically run every other day so I should have had another workout in here so that would theoretically knock me down to the 3-4 day range but I'm okay with that. The convenience of having everything in just the watch for my runs was really what I was after. Once the novelty of things like the notifications wears off I'll probably turn them off which should get me a little bump in battery down the road.

That's great that some are seeing the claimed battery life. Can you also post your software version? Perhaps Garmin has already pushed a fix from the manufacturing side (doubt it, but who knows).

Over on the 230 forum there is a thread on battery life, and they are all raving about it.
The only difference should be the hrm.

So maybe it is that. Is it possible to turn off the hrm and effectively just have a 230 and see if it improves drastically.

Or is there something else about the 235 that is eating power? Or who knows, maybe even a bad batch of 235 batteries.

As well as HR, how often the backlight comes on and how much use of GPS (i.e. in timed activities) will be the major factors.