Hi there, I'm trying to charge my tablet this way
Can someone please tell me why this is not working?
Thank you
I'm new to this forum, so there may be a way to do that, but as far as I know, you can't directly charge a LiIon battery; they have a charge controller. If you by-pass the charge controller, I think you can blow up the battery.
Related
hi everybody!
what I really don't like is, that my MDA Comapct is always charged when I connect it with the usb cable to my computer.
as everybody knows every battery, no matter if li-ion or not, gets worse when charged all the time for short times.
does anybody know if theres a program which deactivates usb charging?
thanks for your help!
stefan
Because of that reason i use bluetooth for sincronization, you can do the same. it's a good solution.
You could modify a usb cable to sync only, by removing the power connections I suppose. It could be made switchable also if you are ok with a solder gun.
as everybody knows every battery, no matter if li-ion or not
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Hi,
interestingly enough, that is not true for LiIon Batteries. The worst you can do is, always decharge nearly completely and then fully recharge. The method that is recommend for all the 'usual' batteries is no good for LiIOn.
http://en.wikipedia.org/wiki/Li-ion e.g.
The dangers of 'deep' discharging are a lot worse than problems with a high number of recharges. The lifetime of a LiIon is NOT dependent from the numbers of chargiong cycles. And with the non-existing memory effect, there is no reason, not to recharge a LiIOn whenever convenient.
So, to summarize, do not worry about charging the MDA via USB.
Regards
marco
Very good link and a very good advice marco99, thx a lot.
got an SDA with no prior knowledge of its history other than "it wouldn't power on" well when I got it the battery was completely dead "0 volts". Since I didn't have an external charger I did a little work to my external MPx220 charger "uses a 3.6v LiIbattery" to fully charge the SDA battery. I put it in and tried the key sequence to get the bootloader to appear.. no go. Tried camera button while I plugged in USB with and without battery.. nothing. So I left it plugged in while I was searching the forums last night for more information the screen turned white and all the keys lit for about a minute then it turned off again.. and I haven't been able to get it to repeat this since.. is there any hope at this point? Thanks!
now I'm confused.. I've seen yet another method for entering bootloader on the Tornado's http://wiki.xda-developers.com/index.php?pagename=HTC_Tornado the camera + botton on opposite side and power.. this doesn't seem to work for me either.. but which one is right? does the battery need to be in or out? usb plugged or unplugged.. I can't believe this device would be so "dead" as to not do anything at all.. will T-Mobile honor the year warranty of these new phones?
Is this model just so new that not much is known about it? I'm surprised that I haven't gotten any type of input yet.
the same problem
hallo
i have the same problem, please if you have found the solution, tell me or send me an E-mail [email protected]
To me it seems like the battery is not charging at all. I've seen this with Motorola Li-Ion batteries. Unless there is enough amperage in the charger, the battery won't charge, regardless of what it looks like. If you really want to go forward with this, one idea may be to get an actual SDA charger, or replacement battery.
bipinsen said:
To me it seems like the battery is not charging at all. I've seen this with Motorola Li-Ion batteries. Unless there is enough amperage in the charger, the battery won't charge, regardless of what it looks like. If you really want to go forward with this, one idea may be to get an actual SDA charger, or replacement battery.
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Or maybe a Motorola charger? USB cable is 5v, Motorola charger w/USB connector is 5.9v. Motorola phones can charge from PC USB port/hub, but only if the phone is turned on. If phone cannot be turned on because the battery is dead, you need the wall charger...
Hi guys,
I know if you unplug a charging phone in and out a lot it kills the battery, however my question is (as this was a big battery killer on my nokia n95) if I plug my touch pro into my pc and it has charged, will it then run purely off external power?
On my n95 it would charge, use a tiny bit of power on the battery and very shortly charge again. Obviously if my battery dipped again by a whole bar id want it to kick in the charger but that was crazy.
I'd like to leave my touch pro plugged in a lot for activesynch etc and charge at the same time so it would be nice to know if it's going to kill my battery.
I find that when the battery is charged the USB power will stop charging it. I charge overnight with my PC off on USB and come back and the full charged status is on.
Your PC should be able to provide 500mA through the port if the Touch Pro requests it, however the standalone charger is rated at 1A (1000mA) so if you are worried about using your device while charging then perhaps use it with the external charger.
I see no reason why your battery wouldnt be charged adequatly by the USB port though, generally you would be using less than your are getting from the usb port.
Scribe said:
I know if you unplug a charging phone in and out a lot it kills the battery
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erm... where did you hear that?
no it doesn't
maybe you mix it with the car ignition eating too much gas if you do it a lot?
Well, it used to be that way with the old NiCd batteries. Nowadays it's not an issue anymore.
My apologies, whilst lithium ion's don't have memory they do still lose overall power by each charge and discharge, even if it's not a complete one.
my 5 years old LOOX 720 disagrees with you
also my 5 year old HP IPAQ disagrees.
battery is as new and i charged it whenever i wanted.
same situation with my HTC Artemis, i bought it since the first day it went on sale and battery is as new!
Upquark said:
Well, it used to be that way with the old NiCd batteries. Nowadays it's not an issue anymore.
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This issue has come up so many times ..... i post again a link to a website with details on how to maximise a li-ion batterry. It clearly states that it prefers small discharges, with full discharges in every 30 charge cycles.
http://www.batteryuniversity.com/parttwo-34.htm
Sorry if this is the wrong board but I'm new to XDA :/
So one day I left my Versus touchtab to charge and then when I came back it wouldn't turn on. The problem is that sometimes when I plug it in the tablet would act as though it's charging but it wont so I run out of charge. My theory is that it didn't charge properly and it's completely out of juice. Please could anyone tell me why they think it's not working and how to fix the issue. Thanks in advance!
P.S It doesn't charge via micro USB and I've already been told to charge it via USB and it's actual charger many times!
Has anyone tried running their Samsung Galaxy Tab 7.7 without a battery? My tab died and I think its the battery. I already replaced the tab with a Nexus 7, so I figured its time to experiment on the old 7.7 like its Frankenstein's monster.
I popped the case and pulled the old battery. I'm thinking of wiring the 30-pin connector's power + and - to where the battery plugs in. That would supply 5v from USB.
But... is 5v too much? The battery has a nominal voltage of 3.7v and can go as high as 4.2v. So I'm afraid to try it because I might fry my tab.
Also, I'm not sure what to do with the third wire on the battery. It somehow tells the tab how full the battery is but testing its voltage. I've got no idea how to fool the tab into thinking the battery is full.
Has anyone tried wiring up 5v to the battery connector? Is it safe?
Does anyone have into on how to fool the battery empty/full indicator?
Thanks in advance,
Tom
Arobase40 said:
Why don't you simply buy a new battery available on eBay ???
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Sure. I could do that, but like I said, I already replaced the tab. So now I'm just experimenting, and I don't want to spend $60+ on an experiment. Plus, I'm not 100% certain that the battery is the problem.
I've got cables and wires and such lying around that I can experiment with for free. I'm thinking of building the unit into an old PC subwoofer/speaker. It would make a cool WiFi speaker/stereo. I may even wire up some old NiMH rechargeables I have lying around from my remote control car days and make the unit portable/rechargeable.
Well, while I had it all apart, I grabbed my meter and checked the voltage on the battery. It was 2.74v, which I guess is below the level that will allow the tablet to power on. So I decided to hook the battery up to a programmable charger that I have for remote control batteries. That charger took it from 2.74v to 4.2v
I put it back in the tablet and powered it up to find the tablet complaining that the battery was at 0%. So I booted into recovery and deleted the battery stats. After that, the tablet correctly identified the battery as being fully charged. I tested the tab for a while and it worked great, though the charge % seems to drop pretty fast. I played a silly game (2048) for about an hour or two and the battery is down to 72% already. I suspect that since I deleted the battery stats, I will need to run it all the way until it shuts down, charge it, and run it some more before the tab "gets a feel" to the battery again.
I think the battery is very suspect and I think I will continue to have problems with it.
So I am still very interested in anyone who has wired up their tab to run without the battery. What voltage did you supply it? Amps? I'm thinking 4.2v at 1.5a.
Tom2112 said:
So I am still very interested in anyone who has wired up their tab to run without the battery. What voltage did you supply it? Amps? I'm thinking 4.2v at 1.5a.
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I think what you want to do can be done..
sorry i cant help you with what to use but ive seen threads before ages ago about a guy
that wired a mobile phone into his company vehicle so he could gps track it for a few months.
The wiring had 3 wires connected to phone to fool it to think it had a full battery he said it worked no problems.
if can work with phone then it can work with tablet?....also with battery removed you could install a socket into the back to plug in the power cable...
Thanks MRBR7. I wish I knew what to do with that third wire!
http://www.makestuff.eu/wordpress/powering-a-mobile-phone-with-no-battery/
I Found that old link...
seems like you need a 82k resister on the middle one....