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When should you recharge watch?

ScottG
over 4 years ago

I don't know if it is just an urban myth or something but I seem to remember hearing you should let a device go down to low battery before charging it to help give it longer battery life (i.e. dont charge it every night let it get down to 10% then charge it).

Is this true or does it make no difference?

  • 0 over 4 years ago

    That used to be true for NiCad batteries, but not for lithium-ion. There are tons of studies out there. In general, the batteries should last about 500 discharge cycles. Don't constantly let it get down  near zero. So without getting OCD about it, keeping it charged up as much as possible should be fine. 

  • 0 over 4 years ago

    Any time it's convenient.  It can't be overcharged.  The higher you keep the charge level, the better you will be prepared for any unexpected activity or use requirement.  Besides, I like being in charge of when I charge my watch (while showering, or other times when I am not usually wearing the watch) when it is convenient instead of having to interrupt my routine to make sure I charge the watch.

    Forget about the urban myths and charge your watch.

    HTH

  • 0 over 4 years ago in reply to gaijin

    Cheers guys thanks very much! I'm going to get in the habit of plugging it into my computer whenever I sit down to it

    Whilst showering though is my favourite time to scroll through my widgets :)

  • +2 over 4 years ago

    To minimize stress, keep the lithium-ion battery at the peak cut-off as short as possible.

    • Lithium-ion does not need to be fully charged; a partial charge is better.
    • Avoiding Very High States of Charge
      For SoCs above 80%, an increasing cathode degradation has been observed. This has led to coupled side reactions and a marked increase of the charge transfer resistance of the NCA cathode. If the SoC cannot be kept in the low or medium SoC regime during long-lasting nonoperating periods to avoid accelerated side reactions at the anode, at least the very high SoCs of 80% and above should be avoided to reduce cathode degradation. However, the beneficial effects of this mean remain limited as the anodic side reactions remain the dominant driver for capacity fade. 

      have a look at battery universaty and studies about it. 

    https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries  : 

    Li-ion does not need to be fully charged as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge because a high voltage stresses the battery.

    Some portable devices sit in a charge cradle in the ON position. The current drawn through the device is called the parasitic load and can distort the charge cycle. Battery manufacturers advise against parasitic loads while charging because they induce mini-cycles. This cannot always be avoided and a laptop connected to the AC main is such a case. The battery might be charged to 4.20V/cell and then discharged by the device. The stress level on the battery is high because the cycles occur at the high-voltage threshold, often also at elevated temperature.

  • +1 over 4 years ago

    I believe lithium batteries are stressed at both full charge and complete discharge. They will have the longest life if charged between 20% and 80%. Occasionally allow complete discharge and full recharge to re-calibrate the % charge meter.

  • +1 over 4 years ago in reply to scarboroughjohn

    I follow the 80-20 rule for all my Lion products where possible - watches, phones, tablets, laptops. The only products that get a full roasting are my action cams, because there is no way to monitor state of charge while charging.

    I charge my 6X Pro Solar to 80% every Friday afternoon and it lasts me comfortably to the following Friday, rarely dropping below 20%, if ever. It may receive a brief interim charge during the week if there is new firmware to install, but that only adds 1-2%.

    The 80-20 guidance applies to EVs too, and that is how I shall treat mine when I get it - in a few years time - unless the battery tech at the time no longer requires it.

  • 0 over 4 years ago in reply to scarboroughjohn

    Fully agree - and technically that is the most correct response...charge to keep it in 20-80% range...

    Needing a watch fully charged before the ultra is fully legitimate - but has nothing to do with the fact that Li batteries DO degrade faster if overcharged... Batteries are not iron-men... and are not replaceable...