Battery & Docking Station Charging Habits

[bluegti02]

So this is my first post on the site. I just flipped through about a dozen threads on this forum after doing a search for my question with no clear answer so here is my research paper/question. I should note, I tried to leave out any "it" or other pronouns in order to avoid confusion. I also use the word, tablet and pad interchangeably as the both mean the actual transformer prime WITHOUT the keyboard dock.

I am basically looking for a good habit to start when it comes to battery health for my pad and keyboard dock station. I have a Transformer Prime TF201-PAD-0215 tablet running ICS 4.0.3. I have a Galaxy Nexus and needless to say, I must have some terrible habits as lately I have to charge it twice a damn day. I know that the dock charges the pad but what I don't get is why it alternates doing so. In other words, say the pad gets to 70% and dock is at 50%, the dock charges the pad for like 15-20% (I'm guesstimating) and then stops before the tablet reaches 100%. That doesn't really make much sense to me. I was think an optimal setting is to tell the dock to always keep the pad at 100% or only charge the pad when it gets to 20% or so. I don't get why the dock starts charging the tab and then stop before a full charge. I figure it is like this so you can use the dock for longer as if it turns on and off as opposed to staying on, the dock would last longer but I was just able to use my dock at 0% and tablet at 50%. Does anyone know what tells the dock to start and stop charging the tablet?

Since there are two batteries with this device, is there a good habit to charge each? I would think, charging both separately would be optimal but not sure. What happens if I charge the pad in the keyboard dock and they are both at 5%? Does the AC "bypass" the dock and charge the pad first and then the dock or does it alternate charging like it does during a discharge?

Is there anyway to have control over charging of the pad and the dock, either native or through an app? I think it would be cool/more efficient if I could tell the dock to not charge the pad until I say so. So when they are both at 100%, I could set the dock NOT to charge until the pad was at 20% and then turn and leave on, dock charging the pad. Another way would be the opposite; set the dock to always charge the tablet so the tablet remains at 100%.So the dock discharges and when the dock reaches 20ish%, it stops charging the tablet and the tablet starts discharging. Just seems better to do full cycles.

Recap:

1. Can I control how charging is handled with the dock and the pad? If not, what's the best way to charge both since I doubt they'd both reach 20% at the same time.
2. What is a good cycle to charge either/both devices? A.K.A. 100% - 20% - 100%? Is it bad to let either/both drop below 20%?
3. Is it bad to leave it plugged in once either reaches 100%? In other words, can you overcharge or ruin the battery if it's left plugged into an AC source after reaching 100% fully charged?
4. Are there any apps meant strictly for the transformer or for its dock? Anything special, tools/utilities or anything, that was designed with this tablet/keyboard dock combo in mind?

Thanks for your patience reading this and look forward to your replies!

 

[digitalslacker]

Recap:
Can I control how charging is handled with the dock and the pad? If not, what's the best way to charge both since I doubt they'd both reach 20% at the same time.
What is a good cycle to charge either/both devices? A.K.A. 100% - 20% - 100%? Is it bad to let either/both drop below 20%?
Is it bad to leave it plugged in once either reaches 100%? In other words, can you overcharge or ruin the battery if it's left plugged into an AC source after reaching 100% fully charged?

The best I have determined is that the charge flow works like this AC > Dock > Tab. Meaning the AC just charges the dock and the dock then, charging or not, will charge the tab.

I think you are thinking too hard about Li batteries. Much of what you are suggesting here is a throw back to the old NiCad batteries and it doesn't really apply any longer

Lithium Ion's are easier and they work completely different.

First, they don't have a memory persay. Some argue that you can get better battery life from an LI if you discharge it completely every so often but that has more to do with the phone's software than the battery.

Secondly, they are rated for a certain number of charge cycles. A cycle is when the battery goes from 0-100%. It doesn't matter how many times it's charged in any given cycle so it's safe to take it off and on the charger as much as you need.
To elaborate on that point for clarity. Lets say your tab is at 100% and you use until it's at 25%. Then you charge it back up to 100% and use it again until it's at 75% and charge it again. That is 1 charge cycle. You took it down to 25 and up to 100 (+75) then down to 75 and up to 100 (+25) which is a round trip of 100% or 1 cycle.

Any LI battery is rated for a certain number of those but how you do it doesn't matter. There isn't really any benefit to fully discharging before you charge or starting a charge at any particular time.

By that logic there isn't really any issue with leaving it plugged in all the time with one caveat. To preserve the longevity of the battery (the number of charge cycles it's capable of, not the capacity of the battery) LIs will never sit and not charge if they are plugged in. What I mean by that is it's not like filling a container with water and just stopping when it's full and the AC switches over to power the phone. When the device is plugged in the battery is being filled. The device draws it's power from the battery, not the AC charger so while charging the battery is trickling down and being refilled by the AC power.
Now, you'll notice something if you look hard at the battery %'s on almost all devices now. They will charge up to between 96-99% and then down to like 92-94% and then back up to 96-99% all while on the charger. This freaks people out and I've seen a ton of threads about how it's an issue or bug or something. It's not. It's a technique used to prevent overfilling the LI and causing damage to the longevity.

Remember that LI's are rated for a certain number of charge cycles. Well you are still using
those charge cycles even if you keep the device on the charger all the time.

So the short of it is you have the luxury of being able to charge when you need to and not have to think about much else. The battery tech is sophisticated enough to handle the rest. So don't worry about it and enjoy your device

I'm not an expert at this, it's just how I heard it explained once on an episode of the Cell Phone Junkie. Anyone that know better please correct me!

 

[strudel#AC]

The best I have determined is that the charge flow works like this AC > Dock > Tab. Meaning the AC just charges the dock and the dock then, charging or not, will charge the tab.

I think you are thinking too hard about Li batteries. Much of what you are suggesting here is a throw back to the old NiCad batteries and it doesn't really apply any longer

Lithium Ion's are easier and they work completely different.

First, they don't have a memory persay. Some argue that you can get better battery life from an LI if you discharge it completely every so often but that has more to do with the phone's software than the battery.

Secondly, they are rated for a certain number of charge cycles. A cycle is when the battery goes from 0-100%. It doesn't matter how many times it's charged in any given cycle so it's safe to take it off and on the charger as much as you need.
To elaborate on that point for clarity. Lets say your tab is at 100% and you use until it's at 25%. Then you charge it back up to 100% and use it again until it's at 75% and charge it again. That is 1 charge cycle. You took it down to 25 and up to 100 (+75) then down to 75 and up to 100 (+25) which is a round trip of 100% or 1 cycle.

Any LI battery is rated for a certain number of those but how you do it doesn't matter. There isn't really any benefit to fully discharging before you charge or starting a charge at any particular time.

By that logic there isn't really any issue with leaving it plugged in all the time with one caveat. To preserve the longevity of the battery (the number of charge cycles it's capable of, not the capacity of the battery) LIs will never sit and not charge if they are plugged in. What I mean by that is it's not like filling a container with water and just stopping when it's full and the AC switches over to power the phone. When the device is plugged in the battery is being filled. The device draws it's power from the battery, not the AC charger so while charging the battery is trickling down and being refilled by the AC power.
Now, you'll notice something if you look hard at the battery %'s on almost all devices now. They will charge up to between 96-99% and then down to like 92-94% and then back up to 96-99% all while on the charger. This freaks people out and I've seen a ton of threads about how it's an issue or bug or something. It's not. It's a technique used to prevent overfilling the LI and causing damage to the longevity.

Remember that LI's are rated for a certain number of charge cycles. Well you are still using
those charge cycles even if you keep the device on the charger all the time.

So the short of it is you have the luxury of being able to charge when you need to and not have to think about much else. The battery tech is sophisticated enough to handle the rest. So don't worry about it and enjoy your device

I'm not an expert at this, it's just how I heard it explained once on an episode of the Cell Phone Junkie. Anyone that know better please correct me!

I think you said it perfectly, I have had my Prime with keyboard dock since sometime in January. I basically have the Prime docked all the time (it is basically an Android laptop for me) and charge it either when the dock is dead and the tablet is getting low or when it is a good time to get both fully charged. Between the two the battery life is phenomenal and it is wonderful having a device that if it is used for a couple hours a day or less can last a week. I haven't powered up my desktop computer in couple weeks and I really don't need to because my Prime/keyboard dock combination serves my computing needs the majority of the time. I am typing this on my Prime right now and if it wasn't for the keyboard dock I would have booted up my desktop to type this.

Long story short, engineers that are interested in battery lifespan probably decided how and when the keyboard dock will charge the tablet. When it comes down to it, charge them when they need to be charged or when it is convenient to do so. Otherwise enjoy your Android laptop and don't worry about the rest, that is what I do and I have zero complaints!