Sirs may you please explain me something .
lem 7 watch has onboard a battery with 580mah right? The doc station charge has onboard a batery 700 mah right?
If so how come I cannot fully charge my watch with a full charged doc station?
U only reach a 75 % !!!
Thanks for your explanation
Cheers
Oct 11, 2018 10:06:23 GMT 1 pacocarvalho said:
Sirs may you please explain me something . lem 7 watch has onboard a battery with 580mah right? The doc station charge has onboard a batery 700 mah right? If so how come I cannot fully charge my watch with a full charged doc station? U only reach a 75 % !!! Thanks for your explanation Cheers
There is a simple explanation providing you understand the basics of how voltage and current work, let me give it a whirl. When you connect your discharged watch on the battery bank the current begins to flow from the battery bank to the battery in the watch. The voltage level in the battery bank begins to slowly decrease. The voltage differential between them is what allows the transfer to take place or it takes a higher constant voltage to make the current flow from one battery to another. Thus the 700mah to 580mah differential. (Consider your car's 12V battery. Your car's alternator charges it at about a constant 13.5 to 14 Volts depending on the level or load on the system, not at 12 Volts.) The principle is the same with the watch battery, your car battery and the battery bank, the alternator. When the Battery Bank is plugged in and charged up, the voltage level in the battery bank will not decrease an appreciable level, similar to the constant output of your car's alternator and it can charge your watch to 100%. If using the battery bank as a standalone device the voltage must be greater than the device it is charging. Also consider that because the watch is powered on it will also be consuming a small amount of the current from the battery bank, which is not available for charging the watch.
At some point on average 50 to 70%, depending on the level when placed on the charger, as the voltage level in the watch battery increases they equalize and the current stops flowing from the battery bank to the watch battery causing the transfer or charge cycle stop. To continue to charge the watch from this point you would need to plug in the battery bank or replenish it to the point where the Battery Bank voltage is higher and the transfer can resume, before placing the watch back on it. Despite this limitation, consider that with a fully charged battery bank, you can still charge the watch to 50 or 60% when out and about and no other source of power is available. A feature not available on any other watch.
Goog morning
Thanks for your qualified and clever explanation.You show knowledge and inspire confidence on your words.
Cheers
Oct 11, 2018 14:21:47 GMT 1 capt jon said:Oct 11, 2018 10:06:23 GMT 1 pacocarvalho said:
Sirs may you please explain me something . lem 7 watch has onboard a battery with 580mah right? The doc station charge has onboard a batery 700 mah right? If so how come I cannot fully charge my watch with a full charged doc station? U only reach a 75 % !!! Thanks for your explanation Cheers
There is a simple explanation providing you understand the basics of how voltage and current work, let me give it a whirl. When you connect your discharged watch on the battery bank the current begins to flow from the battery bank to the battery in the watch. The voltage level in the battery bank begins to slowly decrease. The voltage differential between them is what allows the transfer to take place or it takes a higher constant voltage to make the current flow from one battery to another. Thus the 700mah to 580mah differential. (Consider your car's 12V battery. Your car's alternator charges it at about a constant 13.5 to 14 Volts depending on the level or load on the system, not at 12 Volts.) The principle is the same with the watch battery, your car battery and the battery bank, the alternator. When the Battery Bank is plugged in and charged up, the voltage level in the battery bank will not decrease an appreciable level, similar to the constant output of your car's alternator and it can charge your watch to 100%. If using the battery bank as a standalone device the voltage must be greater than the device it is charging. Also consider that because the watch is powered on it will also be consuming a small amount of the current from the battery bank, which is not available for charging the watch.At some point on average 50 to 70%, depending on the level when placed on the charger, as the voltage level in the watch battery increases they equalize and the current stops flowing from the battery bank to the watch battery causing the transfer or charge cycle stop. To continue to charge the watch from this point you would need to plug in the battery bank or replenish it to the point where the Battery Bank voltage is higher and the transfer can resume, before placing the watch back on it. Despite this limitation, consider that with a fully charged battery bank, you can still charge the watch to 50 or 60% when out and about and no other source of power is available. A feature not available on any other watch.
That's not really what's happening. The truth is that there's a step-up converter which makes 5V always available on the output, but that conversion from 3.7v (nominal) is not free, it's only about 80% efficient. That means that you will loose energy while doing the conversion. Then, there's another converter inside the watch, a step-down converter which takes the 5v and gets them back to the voltage the battery needs (between 3 and 4.2 volts), which is also 80% efficient (average), if you do the maths then I'm sure it will come out to about 75% of real battery charge.
Oct 12, 2018 13:01:26 GMT 1 iscle said:Oct 11, 2018 14:21:47 GMT 1 capt jon said:
There is a simple explanation providing you understand the basics of how voltage and current work, let me give it a whirl. When you connect your discharged watch on the battery bank the current begins to flow from the battery bank to the battery in the watch. The voltage level in the battery bank begins to slowly decrease. The voltage differential between them is what allows the transfer to take place or it takes a higher constant voltage to make the current flow from one battery to another. Thus the 700mah to 580mah differential. (Consider your car's 12V battery. Your car's alternator charges it at about a constant 13.5 to 14 Volts depending on the level or load on the system, not at 12 Volts.) The principle is the same with the watch battery, your car battery and the battery bank, the alternator. When the Battery Bank is plugged in and charged up, the voltage level in the battery bank will not decrease an appreciable level, similar to the constant output of your car's alternator and it can charge your watch to 100%. If using the battery bank as a standalone device the voltage must be greater than the device it is charging. Also consider that because the watch is powered on it will also be consuming a small amount of the current from the battery bank, which is not available for charging the watch.At some point on average 50 to 70%, depending on the level when placed on the charger, as the voltage level in the watch battery increases they equalize and the current stops flowing from the battery bank to the watch battery causing the transfer or charge cycle stop. To continue to charge the watch from this point you would need to plug in the battery bank or replenish it to the point where the Battery Bank voltage is higher and the transfer can resume, before placing the watch back on it. Despite this limitation, consider that with a fully charged battery bank, you can still charge the watch to 50 or 60% when out and about and no other source of power is available. A feature not available on any other watch.
That's not really what's happening. The truth is that there's a step-up converter which makes 5V always available on the output, but that conversion from 3.7v (nominal) is not free, it's only about 80% efficient. That means that you will loose energy while doing the conversion. Then, there's another converter inside the watch, a step-down converter which takes the 5v and gets them back to the voltage the battery needs (between 3 and 4.2 volts), which is also 80% efficient (average), if you do the maths then I'm sure it will come out to about 75% of real battery charge.
So the battery bank acting as the alternator in your vehicle just maintains a constant higher voltage to allow the watch battery to charge. Eventually the battery bank is depleted and the percentage of power transferred depends on the level at the start and the amount of current being consumed by the watch during the charge cycle. For example it would be greater if you had several apps running or Wi-Fi, BT or GPS turned on during the charging process.
I get 36 hrs with Bluetooth, hand bright screen and pedometer on permanently but everything else off unless I need to use wi-fi. Connected with watch droid, which works perfectly, a massive battery drainer is the Google play services update direct from play store. As soon as I installed it I got 6 hrs at best.
I replaced it with Google play services for wear os from APK mirror and everything is good again and no complaints from any app about updating it.