This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Battery, optimal charging in low temperatures, mechanical timer

Hi,
recently I got forerunner 735xt and found that it is fine sporting tool, but not as good watch mainly because of frequent charging. Just my opinion.

So as sporting tool I would like it to be ready when I go running. This would mean to have it in charger while not running. But I hear it is not good for battery? How bad is it? (quality mobile phone wall charger)

I found mechanical timer, you press button on it and it will give power for 30min then it does not draw any power from grid. Plugging charger to it would mean that most of the time forerunner will be connected to the charger with no power in it. Is this a problem?

Place (not home) I run from has temperature at winter 5-10C. Is it a problem to keep forerunner there? Just want to change and go run and not to wait to charge. Plugged in the charger plugged in the mechanical timer?

All I am trying to do is find optimal ratio of comfort use and battery damage.
Anyone with practical experience?

0 Andy275 over 7 years ago

I am not sure I completely understand your concern. While I would not necessarily drain the battery to zero, it holds a charge during activity for quite a while (rated 14hrs, but certainly more than 8hrs). Whether the battery is connected to a timer affects it depends on whether the timer somehow draws a charge from the watch when not powered. But unless you are running ultra marathons, you won't likely need to keep it fully charged and can just power the watch off when not in use.

Cold weather running is not a problem.

For optimal battery care, see: http://batteryuniversity.com/en/learn/article/how_to_prolong_lithium_based_batteries/subscribe_thx

0 mdgarf over 7 years ago

Sorry did not explain properly. For my activities 735xt is more then adequate. But all my running things are at the "running shed", I drive to it, change, run, shower and drive home (trying to repeat every 2-3 days). In this regime any battery will eventually drain. If forerunner is kept at the shed there is not much time to charge it unless I leave it on charger. I just do not know if I can leave it on the charger for 2 days, then use it and plug it again?

In the "running shed" is 10C. I understand that while on hand and running temperature not important.

Timer is mechanical so it really cuts off the power. It would charge it for 30min.

Thanks for the link.

0 Andy275 over 7 years ago

I see. I doubt that the timer would cause a problem unless it drains the battery while off. You can test that. However, charging it does turn the watch on even if off when connected. Depending on the lengths of your runs, you could probably just leave it there and turn it off after each use. You'd likely get at least a dozen runs in. You would want to bring it home anyway from time to time to download (backup) your activities and any new software updates (like the one people are complaining about today ;-)

The only think I might be concerned about leaving in the cold temperature would be the possibility of condensation developing inside (especially if it got much colder than that). It might depend on the humidity.

0 mdgarf over 7 years ago

Thanks for your comments.
had no idea about condensation problem, hopefully it will be OK. Shed should keep above 7-10C.
I do downloads trough mobile phone.
I start to appreciate simple/easy solutions.

0 Andy275 over 7 years ago

I agree with simple/easy. One potential drawback I see with repeatedly charging it unnecessarily every day is that the battery life has a large but not unlimited number of charge cycles. As the power will remain on between charges, you'd likely dray down your battery each day (maybe 10-20%) and then top it off. Just leaving it off and then charging as needed would likely prolong the battery life. In your case, charging with a time (perhaps set to 2hrs) once a month would probably suffice. Even leaving it plugged in for a couple of days wouldn't be a problem. Just my (simple/easy) 2 cents.

0 mdgarf over 7 years ago

I do understand, problem is me. I am creature of habit, once things gets erratic it is a problem.
Charging as needed (every 2 or 3 run means every 4-6 days) ended up many times me siting/reading in the "running shed" waiting forerunner to charge at least for that one run. Because I underestimated the charge or skipped one run. It is OK when it is comfortable trough summer I get stuff done, but at 10C not fun.
I will try to use trough its full range, using timer as a buffer (skipping charge or two). It should work.

0 mdgarf over 7 years ago

Just to update on this.
Switching forerunner off does not help much.
But I found unused internet controlled plug and it works really well.
Forerunner charges quite fast, so I just switch charging on 10-20min before actual run. It will get even from dead to 50%.
Update on forerunner was done trough phone so is uploading my runs.