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Why do 8" tablets have worse battery life than 7" tablets?


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#1 mTab

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Posted 15 December 2012 - 10:26 AM

It's not a rule by any means, but it seems to be the case with the products I've seen. Things like the Teclast P88 only last half as long as the Nexus 7. Granted the screen is larger, but not by that much. Same goes for resolution.

#2 rushking19

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Posted 16 December 2012 - 10:33 PM

because of the bigger screan it uses more engergy to light it up and produce picture

#3 Nickos-V

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Posted 17 December 2012 - 11:16 AM

It's not a rule by any means, but it seems to be the case with the products I've seen. Things like the Teclast P88 only last half as long as the Nexus 7. Granted the screen is larger, but not by that much. Same goes for resolution.

#1. Screen size. About 40% difference. That will take some extra power.

#2. Tegra3 VS Chinese ARM chip. Tegra3 is 4+1. 4 high speed Cortex A9s + 1 "special" low speed Cortex A9 w/max clock of 500 MHz.

The Tegra 3 (codenamed "Kal-El")[18] is functionally a SoC with a quad-core CPU, but includes a fifth "companion" core. While all cores are Cortex-A9s, the companion core is manufactured with a special low power silicon process that uses less power at low clock rate but does not scale well to high clock rates; hence it is limited to 500 MHz.
http://en.wikipedia..../Tegra3#Tegra_3

#3. Asus spent lots of time checking the board design and made sure there was no power loss. They checked every joint for voltage loss & heat. ie. high quality & efficient PCB board design.

#4. Kernel & power saving modes. Each ARM chip maker changes the kernel to work with their chips. They also may have different power modes depending on sleep, idle or use. Tegra3 is made by Nvidia and the Android kernel is made to work with Tegra3 by Nvidia's highly skilled developers.

#5. Different tablet makers can come up with different and better board designs and use different parts too. Thus, some boards (ie. tablets) will provide better power use and performance. Ever notice how well some x86 motherboards can overclock compared to others? The board design and electronic components used matters too.


PS, to be fair, you have to compare 8" Chinese tablet with 7" Chinese tablet and both with the same ARM chip and very close battery size. Do that and you will see that "most" Chinese 7" tablets only get 4-5 hours battery life. ie. very similar to 8" tablets. Momo7 may get 6 hours. Nexus 7 does 8+ hours.

Comparing Nexus 7 to 8" Chinese tablet is not fair because of points 2-5 listed above.

Edited by Nickos-V, 17 December 2012 - 11:23 AM.


*MINIX NEO X5 (RK3066) - OK. Not fun because uses mouse cursor.
*YUANDAO N80 DUAL (RK3066) - Very good
*CUBE U30GT (RK3066)- Defective; buttons broke in 2-3 weeks; Bad quality control!!! I will never buy a Cube again!!! - Very good while working
*WOPAD I7 (RK2918)- About OK. Sluggish because has weaker ARM chip (RK2918) & less RAM (512 MB).