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Hi!
I had a battery probelm (same one everyone else seemed to get with there 1yr old uni) where it cuts out at 60% due to the voltage from the battery dropping below the threshold really fast.
Anyway I got a new battery .. my old one was 1650ma (or something like that) I got this new one which is 1750ma (or something like that).. definitely different.
Now I plug my original charger (5v 1a) into the pda and the charge light turns on .. I leave it for an hour and the battery hasn't charged any.. in fact its lost charge as you'd expect if it had been left switched on with no supply.
So.. I plug my motorola krzr charger (5v 550ma) into it and go for a shower/sh*t/shave come back and the battery has gained 10%.. great! atleast I can charge it now.
I also have a desktop cradle charger (5v 1a), same problem.. it sits there forever and a day and discharges... no charge.. (I only got it when I got my new battery so could not prove it before hand)
USB charging works with no problems (not from the cradle one though). So my question is ... Why?
Could it be something to do with my new battery?? I got it from PDAAddons and they've always been good in the past so I believe I can rule out it being a fake.
My new battery is a Li-on Poly.. I've got to admit I didn't look at my old one to see if that was a poly too ... was definitely a li-on though.
I can live with using my moto charger on my exec but unfortunately the ac adapter for my cradle is of a different connector type (female pin sleeve thingy like nokia) so before I search the world for a 5v 550ma version I could do with knowing if i'm barking up the wrong tree and about to waste my money..
Any electronics whizzes in the house say ho!
anyone? :''-(
Aahaahaa!
I'm here! Now, what you say sounds very interesting and yet very strange, why?
- Normally more current from the charger should be better, you cannot put in the PDA more current than it's factory maximum (which I don't know how much it is, but that's not a problem), the internal charger (inside the PDA) knows how much it is and how to limit, also takes care of the right charging profile for your battery.
- You don't have to worry about the exact battery type you bought, boths are Lithium, so chargind profiles are mostly the same, these (LiIon and LiPoly) are "exchangeable" usually (I've heard of no problems until now, since several years I mean).
- If your battery is discharging means only one thing, you're not puttin current into the battery, you're taking it out of it! So, either you might have a deffective charger, a deffective charging circuit (the one inside the PDA) or a defective battery.
- You can charge the battery with your Moto's charger, so battery is probably ok, you have used your original charger/craddle until now, so they might be ok, you have charged one battery at least to 10% so PDA should be ok.
What can it be?
Possibilities are:
Slightly deffective PDA's internal charging circuit, the fact that you can charge with a lower rating charger (the one for your Razr, thing that I've done myself two weeks ago), might point to this, because you have already "limited" the maximum current to 550mA (Razr's charger max current).
Slightly different battery, most of the batteries do have some kind of thermal protection circuit inside (chip + temp sensor, etc.), if the behavior of this circuit is not "compatible" somethin strange can happen, however I personally consider this option not to be the best.
One or two of your chargers might also be somehow "deffective", why? Your original battery might be ok and you are just having problems with your chargers or your High capacity chargers (the original one and that from the craddle) have some problem to give enough juice to your batteries.
I surely might proceed as follows:
try to charge both batteries with a stand alone charger, this is not an easy task, because Lithium batteries are the most "delicate" types, charging method is the "strangest" one, I have two stand alone battery chargers that came as gift with some Nokia batteries I bought from an Ebay seller, eventually, I could give you the full schematic so you can construct it (if you want and if you can).
In this way I will not have any more suspects from the batteries.
Second, test each of my chargers, it can be done by connecting a medium -and suitable- load to each charger for some minutes.
A wire wound ceramic resistor should do the trick, ie for the Razr charger (5V, 550mA) I could use a 250mA load, R=V/I, so 5V/.25A equals 20 ohm (1.25W max power, use at least a 2W resistor, 3 or 5W better).
If the internal PDA circuit should be defective, take it to fix or try to fix for yourself.
Hope this helps
kecido said:
Aahaahaa!
I'm here! Now, what you say sounds very interesting and yet very strange, why?
- Normally more current from the charger should be better, you cannot put in the PDA more current than it's factory maximum (which I don't know how much it is, but that's not a problem), the internal charger (inside the PDA) knows how much it is and how to limit, also takes care of the right charging profile for your battery.
- You don't have to worry about the exact battery type you bought, boths are Lithium, so chargind profiles are mostly the same, these (LiIon and LiPoly) are "exchangeable" usually (I've heard of no problems until now, since several years I mean).
- If your battery is discharging means only one thing, you're not puttin current into the battery, you're taking it out of it! So, either you might have a deffective charger, a deffective charging circuit (the one inside the PDA) or a defective battery.
- You can charge the battery with your Moto's charger, so battery is probably ok, you have used your original charger/craddle until now, so they might be ok, you have charged one battery at least to 10% so PDA should be ok.
What can it be?
Possibilities are:
Slightly deffective PDA's internal charging circuit, the fact that you can charge with a lower rating charger (the one for your Razr, thing that I've done myself two weeks ago), might point to this, because you have already "limited" the maximum current to 550mA (Razr's charger max current).
Slightly different battery, most of the batteries do have some kind of thermal protection circuit inside (chip + temp sensor, etc.), if the behavior of this circuit is not "compatible" somethin strange can happen, however I personally consider this option not to be the best.
One or two of your chargers might also be somehow "deffective", why? Your original battery might be ok and you are just having problems with your chargers or your High capacity chargers (the original one and that from the craddle) have some problem to give enough juice to your batteries.
I surely might proceed as follows:
try to charge both batteries with a stand alone charger, this is not an easy task, because Lithium batteries are the most "delicate" types, charging method is the "strangest" one, I have two stand alone battery chargers that came as gift with some Nokia batteries I bought from an Ebay seller, eventually, I could give you the full schematic so you can construct it (if you want and if you can).
In this way I will not have any more suspects from the batteries.
Second, test each of my chargers, it can be done by connecting a medium -and suitable- load to each charger for some minutes.
A wire wound ceramic resistor should do the trick, ie for the Razr charger (5V, 550mA) I could use a 250mA load, R=V/I, so 5V/.25A equals 20 ohm (1.25W max power, use at least a 2W resistor, 3 or 5W better).
If the internal PDA circuit should be defective, take it to fix or try to fix for yourself.
Hope this helps
Click to expand...
Click to collapse
I'm gunna buy another 5v 1a charger .. I've had it reported that this cradle charger (5v 1a) doesn't work properly anyway so it may be 2 seperate problems here Thanks for you advice fella much appreciated
Charging anomaly, workaround
vbJoe said:
...Now I plug my original charger (5v 1a) into the pda and the charge light turns on ..
Click to expand...
Click to collapse
Are you absotively, posilutely certain the AMBER charge light comes on fully?
I leave it for an hour and the battery hasn't charged any.. in fact its lost charge as you'd expect if it had been left switched on with no supply.
So.. I plug my motorola krzr charger (5v 550ma) into it and go for a shower/sh*t/shave come back and the battery has gained 10%.. great! atleast I can charge it now.
I also have a desktop cradle charger (5v 1a), same problem.. it sits there forever and a day and discharges... no charge.. (I only got it when I got my new battery so could not prove it before hand)
USB charging works with no problems (not from the cradle one though). So my question is ... Why?...
Click to expand...
Click to collapse
There is some anomaly about charging with a plug-in charger. You may have to turn the device on so that it can recognize the charger, then close it and let it turn itself off; or perhaps it's turn it off then on, I'm not sure, but I've encountered similar oddities with both 110v, 220v, and 12v chargers, and I've seen discussion about this anomaly on this and/or other fora. Once you get the AMBER light, you're fine (as long as it's putting out at least +5v; +5.5 is better).
I think it has something to do with its looking for a [non-existent] USB signal along with the voltage under some conditions, but not others, but that's just a wild guess. Anyway, I don't think there's necessarily anything wrong with your battery, device, or charger. Hope this helps. Cheers,
Thanks for the reply, I'm 100% that the amber light turns on. Not only that the screen brightens so it definitely knows its connected. I've tried several combinations of turning it off/on etc during the charge/before but nothing seems to make this desktop charger actually put anything in the battery.
I have had 5 different "cradle" chargers that have failed.
I don't need one that charges the phone or uses as a sync charger.
I just want a standalone separate battery charger. I'd prefer if it plugged directly into the wall instead of via a cable but either works ok I guess
why not have a look on ebay?
J
Can those found on Ebay be considered reliable? I was hoping that maybe someone has already purchased something similar for the Kaiser and wouldn't mind sharing their thoughts and opinions. I would love to have a cradle for my Tilts so I can charge them and their extra battery. However, a simple battery charger would be nice as well.
I bought this cradle and I'm very happy. Working excellent.
HTC also has a cradle/charger, and though it looks much nicer and taking less space, the price is exaggerated.
There is a a battery charger as a stand alone. From the picture the battery is definitely not genuine, but the price worth it even if you'll throw the battery away. I don't know about the reliability of this seller/product though.
I bought this http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230228595112 did not receive it yet but looks like what I want. Even though it is only USB but I think I can hook it with a USB wall charger that will also charge it direct
Here's one from Sedio with flip-out AC prongs;
http://www.seidioonline.com/index.asp?PageAction=VIEWPROD&ProdID=948
NetSkipper said:
There is a a battery charger as a stand alone. From the picture the battery is definitely not genuine, but the price worth it even if you'll throw the battery away. I don't know about the reliability of this seller/product though.
Click to expand...
Click to collapse
I bought one from ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=250215286540&ssPageName=STRK:MEWA:IT&ih=015
It was very inexpensive, has flip-out ac prongs, and works great. It arrived in about 10 days from HK.
NetSkipper said:
I bought this cradle and I'm very happy. Working excellent.
Do you know if this cradle can charge the extended battery (the one that is 3000mah)? I asked the ebay seller that you reference the same question and he said that he thinks it can, but he was not sure.
Thanks,
K Crumbley
Click to expand...
Click to collapse
kcrumbley, sorry, I don't have the 3000mAh battery so I can't help you.
I bought a 2 pack of these chargers on Woot a while back. They have worked great for me charging spare batteries. Haven't seen them for sale anywhere else (not that I have looked too hard). Highly recommend them if you can find them.
http://www.woot.com/Blog/BlogEntry.aspx?BlogEntryId=2885
NetSkipper said:
I bought this cradle and I'm very happy. Working excellent.
Click to expand...
Click to collapse
And then:
kcrumbley said:
Do you know if this cradle can charge the extended battery (the one that is 3000mah)? I asked the ebay seller that you reference the same question and he said that he thinks it can, but he was not sure.
Thanks,
K Crumbley
Click to expand...
Click to collapse
I have one of those cradles as well and aside from having to do a little 'pin tweaking' with a pair of needle nose pliers (to get the cradle pins to line up with the battery contacts) it works fine. I bought it as a bundle with a spare 1350 mAh battery as well but since the larger capacity batteries still have the same contacts and basic sizes apart from thickness (after all they do fit in the same phone as a standard thickness battery) the higher capacity battery should fit fine. It'll just take longer to charge.
I purchased the Seido charger and it did not work, nor did the replacement they sent. The problem with the design is that it is a universal charger that has inserts for different batteries. Unfortunately the tolerances are not tight and the insert has trouble making contact with the main charger.
http://www.seidioonline.com/index.asp?PageAction=VIEWPROD&ProdID=948
Anyone seen where to buy extra power adapters? Be nice to have one with a longer cable. Stock one is very short.
Wish it was USB charged....
Sent from my Nexus One using XDA Premium App
http://www.androidtablets.net/forum/acer-iconia-tab-a500-forum/13840-chargers.html
Found another forum discussing the lame power cable.
Sent from my Nexus One using XDA Premium App
I couldn't stand it anymore so I snipped my wire and added another 4 ft.
I have been trying to get an additional PSU and car charger for my Acer. Went to Frys, tried almost EVERYTHING they have on those Universal PSU and NONE of them work in the pin connector for the Acer. What gives!
Try to get a free tip for my Energizer Xpal and also result in zero search. Any fellows have a pointer to where in getting the right tip? Thx
So far the ONLY one that I have found that works is the Enercell 12 / 1.5 with the 'G' tip, but it's like $30 at RadioShack. The tip itself is a little long and if it wiggles it will stop/start charging off and on.
I'm working with a few people to find some at decent price for us.
anyone measured the dimensions of the charging tip at all? If worse comes to worse we could always buy a generic 12v 1.5a AC adapter from ebay and buy the tip separately to solder on.
The USB port wont be able to charge the tablet fast enough and the battery will still drain. I've found that this happens on my Xperia X10 mobile phone. I have to disable 3G data in order get it to start charging.
julz said:
anyone measured the dimensions of the charging tip at all? If worse comes to worse we could always buy a generic 12v 1.5a AC adapter from ebay and buy the tip separately to solder on.
The USB port wont be able to charge the tablet fast enough and the battery will still drain. I've found that this happens on my Xperia X10 mobile phone. I have to disable 3G data in order get it to start charging.
Click to expand...
Click to collapse
The 'g' tip for the Encercell is 1.1mm x 3.0mm
Hope that helps
thanks for hte dimensions... unfortunately they don't sell that brand over here in Australia. I'm also reluctant to pay ~$30 for a charger.
I wonder if one of the round tips on this USB charger would fit:
http://www.dealextreme.com/p/10-in-1-usb-powered-charging-cable-for-ipod-psp-cell-phones-34674
It may still charge if the device is switched off completely.
atomicwedgie said:
I couldn't stand it anymore so I snipped my wire and added another 4 ft.
Click to expand...
Click to collapse
Yeah nice one, I was thinking of doing the very same thing as it should not cause any problems.
So did it go ok, what did you use for the extra wire?
________________________________________________________________________
ZTE Blade - Rooted OC 729mh - CM7 RC2 V/nice
Advent Vega - Rooted OC 1.4gh - Corvous5 rom gorgeous smooth and qqqick
Iconia A500 - Rooted - HComb Sweet
I can confirm the Radio Shack Enercell (12vdc, 1.5a) with the 'G' tip works. Picked one up today for $29 (get the tip for free) and its currently charging the Acer as I type this.
Tip: http://www.radioshack.com/product/index.jsp?productId=3807935
Plug: http://www.radioshack.com/product/index.jsp?productId=3807944&numProdsPerPage=60
MJ-12 said:
Yeah nice one, I was thinking of doing the very same thing as it should not cause any problems.
So did it go ok, what did you use for the extra wire?
)
Click to expand...
Click to collapse
No charging difference at all except I don't have to have my face mashed up against the wall while it charges.
I used a piece of wire from an old 1amp charger I had. The extra piece doesn't even get slighty warm. 1.5 amps isn't all that much juice. I did solder the connetions too.
huh and it is only $10 for a new one.
http://us-store.acer.com/product.aspx?pn=LC.ADT0A.024
atomicwedgie said:
huh and it is only $10 for a new one.
http://us-store.acer.com/product.aspx?pn=LC.ADT0A.024
Click to expand...
Click to collapse
Even at $10 it is grossly overpriced
Acer needs to offer a PS with a six foot cable that is not crazy thin like the stock PS.
rushless said:
Even at $10 it is grossly overpriced
Acer needs to offer a PS with a six foot cable that is not crazy thin like the stock PS.
Click to expand...
Click to collapse
True story
Did a quick google on my powersupply PSA18R-120P.
Came up with http://pdf1.alldatasheet.com/datasheet-pdf/view/284284/PHIHONG/PSA18R-120P.html
or
http://www.phihongusa.com/html/pr_psa18r-120p.html
"The PSA18R-120P is priced at $10.23 per unit at OEM quantities"
Assuming they bought off the shelf:
DC Output Connector
2.1x5.5mm Center Positive Standard
For us australians: Going to see if I can visit Jaycar and will report back in with what I find.
Wal-Mart Car Charger
The Wal-Mart Car charger for portable DVD players works perfect.
a quick look at the wall power supply says that it it needs 12V at 1.5 amps with center of tip positive.
The Wal-Mart car charger puts out 2000ma (2amps), and has a tip that works.. It works PERFECT and it only costs 15 bux.
usb charging is out.. usb is only 5V at 500 ma (.5 amp).. not sure why everybody complains about wanting USB to charge their tablet. Even if they did add it, it would take so terribly long to charge it, you would get mad. With the proper charger and voltage, it only takes about 2-3 hours to fully charge the thing...
Good luck!
mikldom said:
The Wal-Mart Car charger for portable DVD players works perfect.
a quick look at the wall power supply says that it it needs 12V at 1.5 amps with center of tip positive.
The Wal-Mart car charger puts out 2000ma (2amps), and has a tip that works.. It works PERFECT and it only costs 15 bux.
usb charging is out.. usb is only 5V at 500 ma (.5 amp).. not sure why everybody complains about wanting USB to charge their tablet. Even if they did add it, it would take so terribly long to charge it, you would get mad. With the proper charger and voltage, it only takes about 2-3 hours to fully charge the thing...
Good luck!
Click to expand...
Click to collapse
This has been a topic of discussions for a LONG time hopefully you'll know.... Couldn't there be a potential issue with charging at 2 amps when it calls for 1.5?? I was told you could use less but not ore without causing damage to the battery?
I have a 'demo' on the way from overseas to try that I should get Wednesday. I will let you know ASAP.
This is a big issue with me as I prefer a charger at home and the office and I'd like something that I can charge on my desk 'without my face mashed up against the wall' (as atomicwedgie so perfectly put it)
it2steve said:
This has been a topic of discussions for a LONG time hopefully you'll know.... Couldn't there be a potential issue with charging at 2 amps when it calls for 1.5?? I was told you could use less but not ore without causing damage to the battery?
I have a 'demo' on the way from overseas to try that I should get Wednesday. I will let you know ASAP.
This is a big issue with me as I prefer a charger at home and the office and I'd like something that I can charge on my desk 'without my face mashed up against the wall' (as atomicwedgie so perfectly put it)
Click to expand...
Click to collapse
The Amp rating on wall chargers is what the charger is CAPABLE of outputting, not what it is always outputting. As long as there is current limiting built into the charging circuit (which is a must), then the charging circuit in the A500 won't pull any more amperage than it needs to charge. Don't worry about buying a higher amperage charger than is needed, but do worry about buying one that is lower as it can overload the charger.
silic0re said:
The Amp rating on wall chargers is what the charger is CAPABLE of outputting, not what it is always outputting. As long as there is current limiting built into the charging circuit (which is a must), then the charging circuit in the A500 won't pull any more amperage than it needs to charge. Don't worry about buying a higher amperage charger than is needed, but do worry about buying one that is lower as it can overload the charger.
Click to expand...
Click to collapse
Absolutely correct.
silic0re said:
The Amp rating on wall chargers is what the charger is CAPABLE of outputting, not what it is always outputting. As long as there is current limiting built into the charging circuit (which is a must), then the charging circuit in the A500 won't pull any more amperage than it needs to charge. Don't worry about buying a higher amperage charger than is needed, but do worry about buying one that is lower as it can overload the charger.
Click to expand...
Click to collapse
Yes... pulling too much amperage is a very bad thing.
Hi!
I made big big big mistake. I thought I am able to make the inductive mod and solder it directly to the usb connector of the phone. Big fail! Dumb me...
First everything was working but then I wanted more and tried to resolder the new cable to the very small VCC pin of the usb connector. Puff and nearly the complete pad for USB VCC disappeared :-(. Seems I soldered to hot or to long.
I now have a phone which I can't charge any more. Right now I'm on 30% battery so I don't have much time...
I think there are some possibilities:
1st:
Find out where the USB VCC pin goes and solder a cable from there. Right now I had no luck and I can't measure with a ohm-meter to find an other pad with the same net. I also have no board layout from the pcb. Maybe someone of you can help with measuring or pcb data?
2nd:
I find a temporary solution by charging the battery (i have to of them) manual with a lab power supply and some resistor? Does anybody know the max ampere load for the battery of the SGS? Any ideas for charging voltage and series-resistor value?
3rd:
Is there a way to get a working main pcb for the GT-I9000? Maybe from a phone with a defect display? This shouldn't cost too much since I am also thinking about a new model.
4th:
Will it blend? Kaboom? Burn baby burn? ...
Hope I can get help with this!
Well you need a hardware engineer to answer you and here youll rarely find one.
hit thankxx if i helped. sent from my mind through telepathy (ya its possible)!
Purchase another battery (have at least 2) and an external battery charger.
upichie said:
Purchase another battery (have at least 2) and an external battery charger.
Click to expand...
Click to collapse
I already have 2 batteries. Where do I get such a "external battery charger"? Most of them seems to use usb connectors and this is broken on my phone.
Search for it on ebay and if ypu cant find one search for it on google.
hit thankxx if i helped. sent from my mind through telepathy (ya its possible)!
BHuvan goyal said:
Search for it on ebay and if ypu cant find one search for it on google.
Click to expand...
Click to collapse
For example, one of these.
(Note: I merely searched "i9000 battery charger" and sorted by price. I in no way recommend, have tested, or endorse the usefulness of the previously linked to product.) ...
fpdragon said:
...
2nd:
I find a temporary solution by charging the battery (i have to of them) manual with a lab power supply and some resistor? Does anybody know the max ampere load for the battery of the SGS? Any ideas for charging voltage and series-resistor value?
...
Click to expand...
Click to collapse
it is dangerous but possible:
use a precision voltage source of
4.195 V +- 10mV
and a series resistor of 2.2Ohm, 1%, 1/2W
if your batt is down to 3.3V it will start charging with about 400mA and goes up to 4.195 V ( will need several hours, you can charge it over night)
never charge to a voltage above 4.210V !!! your LiIon batt will die !!!
best solution is: go and buy an external charger with a battery (approx. 12-19€ with shipping) on ebay
look for a polarcell 1800mAh batt, like this one
http://goo.gl/Cun7U
it's worth the money, i've bought one and use it since two weeks and am very pleased with it.
But be careful, there are some other batterys from hongkong, which also claim 1800mAh, but they don't have it, i had one too and it measured only 1300mAh.
tiwag said:
it is dangerous but possible:
use a precision voltage source of
4.195 V +- 10mV
and a series resistor of 2.2Ohm, 1%, 1/2W
if your batt is down to 3.3V it will start charging with about 400mA and goes up to 4.195 V ( will need several hours, you can charge it over night)
never charge to a voltage above 4.210V !!! your LiIon batt will die !!!
best solution is: go and buy an external charger with a battery (approx. 12-19€ with shipping) on ebay
look for a polarcell 1800mAh batt, like this one
http://goo.gl/Cun7U
it's worth the money, i've bought one and use it since two weeks and am very pleased with it.
But be careful, there are some other batterys from hongkong, which also claim 1800mAh, but they don't have it, i had one too and it measured only 1300mAh.
Click to expand...
Click to collapse
thanks for the detailed infos.
I already have one of these 1800mAh batteries and my subjective impression was good. The second battery I have is the original one.
I will buy one of these charging adapters. Until it is coming I was thinking about using a labratory power supply with your mentioned 2,2Ohm Resistor and with a Ampere limitation of 400mA. Should be no risk, isn't it? Then slowly rise the voltage until I get the current of about 300mA.
The thing is... I have no spare phone and I really would need it on Monday.
I configured the power supply to 4,21V at 400mA max (current delimiter).
It startet at about 4V and I had a constant 400mA load. After about one hour the current delimiter switched off and I now have stable 4,21V. The current lowers slowly.
I think this should be a save charging procedure?
Guys, I've looked around some, but can't find the information I need for this project. I've come into posession of a friend's Nexus 7 8GB that's cracked, as I have two projects in mind for it. The first is making my own external battery pack with the battery from the tablet.
I know the battery is rated for 3.7V at 4325mAh. A standard USB input is powered with 4.5-5.5V. I'm somewhat electrically knowledgeable, but I'm stumped on how to make sure I don't fry my phone or my Nexus 7 by plugging this battery into the USB port. My other dilemma is charging the battery back up, I'm assuming that this will take a small circuit to do.
Any ideas?
Thanks,
Austin
atminside said:
Guys, I've looked around some, but can't find the information I need for this project. I've come into posession of a friend's Nexus 7 8GB that's cracked, as I have two projects in mind for it. The first is making my own external battery pack with the battery from the tablet.
I know the battery is rated for 3.7V at 4325mAh. A standard USB input is powered with 4.5-5.5V. I'm somewhat electrically knowledgeable, but I'm stumped on how to make sure I don't fry my phone or my Nexus 7 by plugging this battery into the USB port. My other dilemma is charging the battery back up, I'm assuming that this will take a small circuit to do.
Any ideas?
Thanks,
Austin
Click to expand...
Click to collapse
Hey Austin,
tell us exactly how you would like this battery to be used-
1. do you want to recharge battery over the USB port?
2. for what exactly you want to use the battery? For some other device? or for Nexus 7? Be more specific please.
I would generally advise if you want to do cool thing like
"external battery that can be hooked to device on-the-go as a mobile range extender"
you want to do this?
in this line of thinking we take note of;
-Voltage of battery nominal
-Voltage of the charging sources (110V,220V,USB +5V /4.5-5.5V/ )
+now when you are sure of this here you go
-at the bare minimum;
- resistors to lower the voltage in/reduce charging current (yes,minimalistic circuit),with a method to check/determine when battery is nearly full 99% cap as per li-ion battery requirement.Take note lithium ion batteries are absolutely forbidden to be overloaded or else kaboom!, self destruct, fire etc./take a look at youtube "li-ion self destruct"
-dig the li-ion charge reqs and methods from the available knowledge sources (e.g. the internet,electronic forums)
Are you up to this project?Wanna companion for this?Just let me know..
You need 3 things to use a raw battery as a USB source:
- a boost converter, to convert the battery's approximately 3.7V to a stable 5V
- a battery charger
- a protection circuit
The protection circuit is very important. If you over-discharge or over-charge a Li-ion battery, you can run into (explosive) trouble.
The battery may have a circuit on board. Can you see any circuitry in the cell? How many wires come out of it?
For example, eBay has plenty of random parts that should do the job:
Protection unit
Charger
Boost converter
You'll want to be really careful if the battery doesn't have on-board protection circuity. Lithium based batteries tend to explode or catch fire if they're improperly charged. Heck, you even hear about it happening to batteries in phones while they're in peoples pockets. Though I would assume some are from dodgy third party batteries.
You might be able to use something like the LiPo Rider Pro which is a premade board for charging Lithium Polymer batteries. It has two USB ports, one for charging and one for supplying power.
If you've never designed a power supply PCB before then I recommend using a ready made device like that, otherwise you could end up getting burned, literally.
A few years ago I just used one of those big 6V batteries and put a USB connector on it. Worked without any problems!
jhlaird said:
You need 3 things to use a raw battery as a USB source:
- a boost converter, to convert the battery's approximately 3.7V to a stable 5V
- a battery charger
- a protection circuit
The protection circuit is very important. If you over-discharge or over-charge a Li-ion battery, you can run into (explosive) trouble.
The battery may have a circuit on board. Can you see any circuitry in the cell? How many wires come out of it?
For example, eBay has plenty of random parts that should do the job:
Protection unit
Charger
Boost converter
Click to expand...
Click to collapse
This is of interest to me. I have a Zerolemon 7000mah battery and I'd like to use it as a recharging power pack for my i747 Gs3. With the newer high capacity batteries, this seems like a natural to me--if I'm out somewhere and don't want to put the Zerolemon in my Gs3, just hook it up to recharge. Is the lack of this kind of accessory due to varying battery types? I'd buy something like this if I could find one.
How to make it:
atminside said:
Guys, I've looked around some, but can't find the information I need for this project. I've come into posession of a friend's Nexus 7 8GB that's cracked, as I have two projects in mind for it. The first is making my own external battery pack with the battery from the tablet.
I know the battery is rated for 3.7V at 4325mAh. A standard USB input is powered with 4.5-5.5V. I'm somewhat electrically knowledgeable, but I'm stumped on how to make sure I don't fry my phone or my Nexus 7 by plugging this battery into the USB port. My other dilemma is charging the battery back up, I'm assuming that this will take a small circuit to do.
Any ideas?
Thanks,
Austin
Click to expand...
Click to collapse
Steps:
1. Learn or know battery and charger technology - especially concerning heat and fire safety. You do not want your house or car burn down "just because you hacked together a little interesting project". Take full consideration of all the sides of it. Experience..
2. Do it.
3. Share it here.
4. Evolve the design together with electronic-savy guys here.
Thats that.
Aside of the notes above - it is an interesting stuff if you have time for it.