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Samsung Galaxy S2
Freedom Kira:
There are a few flaws with the source. But first, let me start off with a disclaimer that by "complete discharge" I do not mean "0% remaining" - I mean when the phone shuts itself off due to low power. Completely discharging a battery past the threshold that phones and laptops set (about 3%) is much more damaging than partial discharge charging could ever be.
Anyway, let me continue here. First thing I noticed was the fact that they showed graphs for lithium polymer batteries for Figure 1. Lithium polymer and lithium ion batteries are very different technologies and work very differently.
If you look at Table 2, you will see that a 10% discharge will result in 4700 charge cycles while a 100% discharge will result in 500 cycles. If you do the math, the 10% discharge gives you 470 full cycles worth of battery charge. That does not seem very attractive. However, the 50% result giving 1500 cycles is interesting - that's 750 full cycles worth. Perhaps there is some merit there, and some discharge level that is best for the battery.
Anyway, from my understanding, the whole full discharge thing was a much bigger problem with nickel-metal hydride batteries. It had to do with sending a current through the battery while the chemical reaction had not completely proceeded in the operational direction, forcing the reaction to reverse early, resulting in some wear and tear. Lithium ion batteries are built differently and the backing technology is always improving, so the "memory effect" is probably not as prevalent anymore.
If you observe people with laptops, though, the ones that complain the most about their battery life being extremely short are those that plug in their laptops whenever they get the chance and use the battery when they don't. That should be saying something.
mrdkreka:
Do you got any proof or sauce that your claim is correct?
--- Quote from: Freedom Kira on April 15, 2012, 11:48:26 PM ---If you observe people with laptops, though, the ones that complain the most about their battery life being extremely short are those that plug in their laptops whenever they get the chance and use the battery when they don't. That should be saying something.
--- End quote ---
Not really I got the opposite result, when I was observing my class.
Here is another sauce
kitamesume:
memory effect... seriously?
http://www.hardwaresecrets.com/article/The-Truth-About-NiCd-Batteries/292
--- Quote ---What is this ”memory effect“ anyway?
”Memory effect“ is when your battery ”thinks“ that it is fully charged but it isn’t. So let’s say that is 70% charged but it ”thinks“ that it is 100% charged. Under this condition, when installed on its charger it will stop recharging, because it is thinking that it is already full. When you start using your gadget, it will last shorter, since it is only 70% charged – and thus the assumption that older NiCd batteries last less than brand new ones. Which is true, but that are ways of preventing the ”memory effect“ to occur.
--- End quote ---
--- Quote ---That’s why newer rechargeable battery technologies do not use Cadmium anymore (e.g., Nickel-Metal Hydride [NiMH], Lithium-Ion [Li-ion] and Lithium-Ion Polymer [Li-Pol]). Laptop computers, cell phones, cordless phones and motherboards found today on the market don’t use NiCd batteries anymore and you won’t have any kind of problem or ”memory effect“ if your electronic gadget uses a different battery technology from NiCd. Just to make sure, if you take a look at your battery you will find a sticker showing which battery technology it uses. If it isn’t NiCd, you won’t have the ”memory effect“ problem.
--- End quote ---
--- Quote ---Batteries not based on Cadmium do not suffer from ”memory effect“.
--- End quote ---
Freedom Kira:
Fair enough, I stand corrected. I'll accept kita's source (too tired to think really).
--- Quote from: mrdkreka on April 16, 2012, 10:50:56 AM ---Not really I got the opposite result, when I was observing my class.
--- End quote ---
That's really interesting. Perhaps the issue has more to do with the fact that their batteries are always being charged up to 100% and heated up in the process?
mrdkreka:
--- Quote from: Freedom Kira on April 17, 2012, 07:37:14 AM ---Fair enough, I stand corrected. I'll accept kita's source (too tired to think really).
--- Quote from: mrdkreka on April 16, 2012, 10:50:56 AM ---Not really I got the opposite result, when I was observing my class.
--- End quote ---
That's really interesting. Perhaps the issue has more to do with the fact that their batteries are always being charged up to 100% and heated up in the process?
--- End quote ---
A theory build on heat being the biggest cause of shorting amount of battery power are quite possible. I have had two HP pavilion, which both had habit of becoming a bit to hot, and the time it took for them to become useless on batteries was ridiculous (roughly a year if I remember correctly).
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