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Is there a section to talk about Java ME? Apps, etc. (7)
to General by teroyk - 22 hrs, 57 mins ago - more...
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2009-10-03
, 20:30
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Posts: 145 |
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Joined on Dec 2007
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#32
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Update: I had several problems with Mugen batteries, and now can not recommend them. In addition to the flaky lugs mentioned above, the capacity of my Mugen battery is not any higher than the Nokia battery, advertised claims to the contrary. And two batteries I've had were unable to survive a deep discharge, unlike the Nokia batteries.
Regarding capacity, here are the results from some tests I ran:
I used flip clock to keep the N810 awake, and browsed to a web page that I set to refresh every five minutes. As the graph shows, the capacity of the new "1800 mAh" Mugen, on two different runs, was about the same as the well-used 1500 mAh Nokia, which had been deep discharged on several occasions. The other 3rd party battery (magenta line) was marked 1300 mAh, and indeed it has less capacity.
(Li batteries gain capacity when used for a bit, so I ran the Mugen through a few cycles before and during these tests.)
The real problem, though, is an inability to survive deep discharge. When I first purchased a Mugen battery, I put it in the N810, connected the charger, and then tried to boot the N810. Well, this is a mistake. I figured it would run off the charger, but apparently during the boot process the charger is cut off, and there was not enough juice in the battery to get through the boot.
Too late, I remembered having the same experience with the Nokia battery when I first got the N810. It had to be charged up a while before booting, even with the charger attached.
But unlike the Nokia battery, the Mugen was unable to survive this treatment. It would not charge any more, either in the N810 (which refused to go into charge state) or in a third-party charger.
Mugen generously exchanged the battery. But the other week I inadvertently left the N810 with the Internet radio on, and ran the new Mugen battery down. That killed it.
This doesn't happen with the N810 batteries. If they run down, the N810 shuts off, I recharge, and they recover (although no doubt a bit worse for wear).
Mugen customer support has been responsive down the line. They said that the lugs work with all the other devices that take a BP-4L, but are redesigning them to work with the N810. However, they have not responded in almost two weeks to my report about the batteries dying after one discharge.
Regarding capacity, here are the results from some tests I ran:
I used flip clock to keep the N810 awake, and browsed to a web page that I set to refresh every five minutes. As the graph shows, the capacity of the new "1800 mAh" Mugen, on two different runs, was about the same as the well-used 1500 mAh Nokia, which had been deep discharged on several occasions. The other 3rd party battery (magenta line) was marked 1300 mAh, and indeed it has less capacity.
(Li batteries gain capacity when used for a bit, so I ran the Mugen through a few cycles before and during these tests.)
The real problem, though, is an inability to survive deep discharge. When I first purchased a Mugen battery, I put it in the N810, connected the charger, and then tried to boot the N810. Well, this is a mistake. I figured it would run off the charger, but apparently during the boot process the charger is cut off, and there was not enough juice in the battery to get through the boot.
Too late, I remembered having the same experience with the Nokia battery when I first got the N810. It had to be charged up a while before booting, even with the charger attached.
But unlike the Nokia battery, the Mugen was unable to survive this treatment. It would not charge any more, either in the N810 (which refused to go into charge state) or in a third-party charger.
Mugen generously exchanged the battery. But the other week I inadvertently left the N810 with the Internet radio on, and ran the new Mugen battery down. That killed it.
This doesn't happen with the N810 batteries. If they run down, the N810 shuts off, I recharge, and they recover (although no doubt a bit worse for wear).
Mugen customer support has been responsive down the line. They said that the lugs work with all the other devices that take a BP-4L, but are redesigning them to work with the N810. However, they have not responded in almost two weeks to my report about the batteries dying after one discharge.
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2009-10-05
, 16:07
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Posts: 1,258 |
Thanked: 672 times |
Joined on Mar 2009
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#33
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Originally Posted by bilofsky
I have a mugen battery for N800. The advertising and text on the battery claims 1800mAh, but the battery itself tells the N800 that it's 1300mAh, which is roughly correct according to my own tests.
the capacity of my Mugen battery is not any higher than the Nokia battery, advertised claims to the contrary.
And two batteries I've had were unable to survive a deep discharge, unlike the Nokia batteries.
The most damaging state of charge for Li-Ion batteries is empty and full. The more time you spend at empty, even the 3.2V empty state, damages the battery and reduces capacity. High temperature further accelerates degradation.
I used flip clock to keep the N810 awake, and browsed to a web page that I set to refresh every five minutes. As the graph shows, the capacity of the new "1800 mAh" Mugen, on two different runs, was about the same as the well-used 1500 mAh Nokia, which had been deep discharged on several occasions. The other 3rd party battery (magenta line) was marked 1300 mAh, and indeed it has less capacity.
(Li batteries gain capacity when used for a bit, so I ran the Mugen through a few cycles before and during these tests.)
The real problem, though, is an inability to survive deep discharge. When I first purchased a Mugen battery, I put it in the N810, connected the charger, and then tried to boot the N810. Well, this is a mistake. I figured it would run off the charger, but apparently during the boot process the charger is cut off, and there was not enough juice in the battery to get through the boot.
But unlike the Nokia battery, the Mugen was unable to survive this treatment. It would not charge any more, either in the N810 (which refused to go into charge state) or in a third-party charger.
Mugen generously exchanged the battery. But the other week I inadvertently left the N810 with the Internet radio on, and ran the new Mugen battery down. That killed it.
| The Following User Says Thank You to shadowjk For This Useful Post: | ||
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2009-10-12
, 01:06
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Posts: 145 |
Thanked: 33 times |
Joined on Dec 2007
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#34
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Originally Posted by shadowjk
Oh, please don't think I disabled that. I wouldn't even know how.
The software on the tablets should shut down before 3.2Volts though, but there are ways to disable that. I hope you didn't.
Originally Posted by shadowjk
battery-status.
What did you use to take the measurements?
Originally Posted by shadowjk
I inferred this from the Mugen instructions, which say:
Originally Posted by bilofskyNot generally true for Li-Ion, though some manufacturers recomend it for LiFePo4 chemistries.(Li batteries gain capacity when used for a bit, so I ran the Mugen through a few cycles before and during these tests.)
"The first time, please charge the battery in the device for at least 8 hours ... After fully charged, please use the device until the device tells you the battery is verly low, then recharge. Repeat this process for 2-3 more times, where after (sic) you can recharge the battery whenever is suitable. Important: NEVER drain the battery completely to 0%."
Originally Posted by shadowjk
If you say so. But as I said, the original Nokia battery that shipped with my N810 wouldn't boot either in the same situation.
Originally Posted by bilofskyThat's a seriously defective battery. If the battery has been shipped empty, then it will have degraded seriously during storage and transport, to the point that it might even pose a safety hazard.The real problem, though, is an inability to survive deep discharge. When I first purchased a Mugen battery, I put it in the N810, connected the charger, and then tried to boot the N810. Well, this is a mistake. I figured it would run off the charger, but apparently during the boot process the charger is cut off, and there was not enough juice in the battery to get through the boot.
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2009-10-12
, 04:27
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Posts: 1,258 |
Thanked: 672 times |
Joined on Mar 2009
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#35
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Those mugen instructions are probably more an attempt to make the battery meter calibrate itself... Unfortunately I don't think it ever does 
George Fragos
Internet Coach & Writer
Maemo Mapper HowTo
Personal Blog -- 3 Joe's Blog
N810 -- 5.2010.33-1