Solar Charge ? - Asus Eee Pad Transformer Prime

Does anyone know of a solar charger that will actually chearge the prime ? i have a freeloader solar charger with an internal 1200mAh battery that can ouput 5v 500mA and a Hymini Wind charger that has a 1200mAh internal storage that can output 5v 850mA
Both of these can alledgedly charge an Ipad but neither of mine seem to have the grunt to kick the charging circuit into life on either the tablet or the dock.
I just I want something that i can use to keep the unit topped off whilst i'm travelling around Greece
Before anyone says it, i understand the limitations of solar charge. from using it for my phone know they take many hours to charge their internal batteries and the loss associated with then dumping that charge into your device.

Not at 5v it won't

You'll need 15v to charge at normal rate, or 12v at a slower rate. 5v it will only charge completely off, and then only very slowly.

i take it that's just the tablet and not the dock ?

Harani said:
i take it that's just the tablet and not the dock ?
Click to expand...
Click to collapse
Either. The maximum input voltage for either is 15v.

ok cheers,
I thought it wasn't charging at all but i've read elsewhere that the charging light will not come on and that it will take up to 16 hours to fully charge on 5v
if that's true then if the solar charger is 1200mAh and is pushing out 500mA then it's only going to be able to charge the pad for just over 2 of the required 16 hours (i think ?) before it's depleted
I'll run some experiments and see exactly how much charge it will put into it overnight but it doesn't seem like it will be a practical thing to use.

Related

Maximum charger amperage?

Alright, so I have a mini USB car charger that is rated at 2.0A (got with GPS) and I just want to make sure the extra amperage is not going to charge my battery too quickly and then kill it in the process. All I have to go on is that my wall charger is capable of only 1.0A and the computer USB is on the level of mA. Does anybody have a car charger or know the maximum amperage possible that these phones can take?
Thanks in advance.
Its to Strong ! I have Crash a PDA with 1.5A
I've used a 2.0a charger but noticed that the battery didn't charge right.
On that note, also noticed that a .5a or 500mA charger after about 6 months killed my battery. (burned out and won't take a full charge anymore)
Recommendation is to stick to 1.0A charging as much as possible as the Wizard's charge circuit is designed at 1.0A charging and monitoring.
DOESN'T MATTER ..if u know the basic Ohms Law..its the max capacity of the charger.(or any source) the current regulating circuits will take care of the real charging current fed to the battery
I charge my phone on my computers USB connection all the time, all computers have a maximum of 500mA USB current.
Amps are pulled from the charger, not pushed to the phone.
Voltages are pushed to the phone, not pulled from the charger.
If the phone draws too much current from the charger, the voltage drops to a point where the maximum power (P (Watt) = U (Voltage) * I (Amps)) of the charger isn't exceeded.
According to the USB specification you need at least 200mA with 500mA recommended +5VDC.
More is never a problem, you could even use a 50A power supply without breaking your phone. Practically spoken: I wouldn't do that.
huh?
I have messed up a few devices before by putting the wrong charger on the device (2.0 amp charger on a droid eris and 1amp charger on the MOTOACTV) Is this a problem with the device's charging circuit? In general it should only pull up what it needs to charge but my devices were messed up?
I returned the first MOTOACTV after it wouldn't leave the boot screen and the second one I got acted funny on 1 amps as well. It charged fine on .75amp charger that came with the device but when I put it on my HTC Dinc charger it shot up from 10% to 20 to 30 etc. all within minutes. Hope I didn't mess this one up too.
Just trying to figure out what the deal is. My phone for sure charges faster when connected to 1amp vs .5amp (computer). This makes sense I understand because the device is able to handle 1amp, but I wonder if it would mess up with a 2amp charger.
Thanks!
The last two posts of 2008 are correct. Your phone is capable of drawing more than 500 mA but less than 1000 mA. If the charger is 1A, 1.5A, 2A, or 50A, it won't make a difference to the phone's charging time or life.
Wrong voltage can be bad, but phones are designed to support USB charging, as a minimum, and 1A to 2A is always safe. As was said in 2008, the charger pushes voltage to the battery, but the battery pulls current from the charger.
That's a really good way of describing it
Pushing and pulling current and voltage is a really good way of describing it.. Given that I am theoretically well within the charging parameters, how comes my phone (Galaxy mini/pop) becomes unusable when its charging (touch screen doesnt touch and screen jumps to new screen without touching?) Am I wrecking my phone?
No, your charger is to blame. Maybe it isn't properly grounded. Phones with capacitive touch screens (not the Wizard! but maybe your phone) can get really weird on some chargers. I have a Nexus One with an aftermarket charger that always makes the touch screen go haywire. When I use an HTC charger, the phone has no problem. As far as I know, the damage isn't permanent, it's just that the sensors get confused. When I disconnect from the charger, turn the phone off, then turn it on, all is well.
My wizards were never bothered by chargers, no matter what kind, as long as they were mini-USB, they were the right voltage. The wizard doesn't take as much current as more modern phones, either.
Hmm. Not properly grounded sounds very plausible. Viva mediterranean circuits. Thanks
Usb chargers will be rated at 5v, which is exactly the correct voltage to charge your device. What you want to make sure is you buy the correct "rated" amperage. Not because it will damage your phone. Amperage only exists as a sum of the power used by the device. You want to find a decent 1amp (1000mA) or higher if you wish, rated usb charger. The the mains charger for your phone is only rated at 1amp, so a 1amp charger is adequate. Avoid 500ma chargers as it will take twice as long to charge and gps / satnav applications will drain the battery even when charging at that rate.
Also if you have a new pc, most of the decent boards will specify 1amp charge even when off if it has on/off charge stated on manufacture details.
Newer phones will charge fine with higher amperage
The myth that charging your device at a faster rate will reduce the life of your device’s battery is false!
If you want quicker charging, look for a wall or car charger that delivers 2100 mA of current at 5 volts higher won't matter.... These lithium ion batteries can handle it... It was just back then if you were to try to put a faster charger in an older battery it (in any cases) just won't charge.

max Charging mAh

Hey, i am trying to figure out what type of charger should i get for Vibrant GPS and accessories in my car. Ive read that using a normal charger such as 500mAH doesn't actually "charge". The Vibrant would actually use more than the charger could charge. I read in the other Galaxy S forum(i9000) that someone used a 2000mAh but never replied after that. Would going that high with a charger damage the battery?
I think you are good to go with a 1,000mAh. The 500mAh will charge a phone overnight without warming up the phone but its not enough juice if you are having the screen on, using GPS, etc.
The phone will only use what it needs to. 500ma is standard for USB, 1000ma is the norm for a wall charger. Its doubtful that the phone would use more than that, but nothing would be hurt by trying, as long as it is a 5V USB charger.
To expand on what Saiboogu wrote... the amperage rating of the charger is the capacity of the transformer -- how much it *can* supply, not how much it *will* supply. The phone decides how much juice to pull.
It's voltage that you have to be careful with. You want to buy a charger that outputs *only* 5 volts.

Extended battery for the S7?

Any third party extended battery options for the S7? I prefer the slim version if possible.
Sent from my SGH-T849 using XDA App
I rigged up a battery pack using 4 rechargeable Energizer AAA's and just plug it into the DC power socket and double-sided taped it to the back of the unit
I imagine I could use some left over spare Li-Ion batteries from other phones though.
UPDATE: someone asked how
STEP 1: Buy something similar to this http://www.littlebirdelectronics.com/products/4%2dAAA-Battery-Holder.html
STEP 2: Buy a male plug that fits the female power socket on the S7 Like this but the correct size http://www.littlebirdelectronics.com/products/1.3MM-PLUG%2d2.5MM-SOCKET-DC-ADAPTOR.html
STEP 3: Solder them together so that the + and - charge come out of the same wires as the wall-charger
STEP 4: Plug in batteries
If this looks/sounds difficult, don't even attempt it, you WILL break your tablet.
Since the original battery do last too long, i found this 2 option that i think that work with S7:
Good price and free shipping
lol i cant post links yet, sorry guys...
here goes the links for the battery extender....
http://www.dealextreme.com/details.dx/sku.4284~r.14121877
http://www.dealextreme.com/details.dx/sku.48449~r.14121877
Nice guys! I was searching for an internal battery solution.
These battery packs look nice but be carefull, the output is only 500 mA. The S7 charger is a 2amp output charger. I'm not sure how well it will run on a lower input.
Ives
mowermech said:
These battery packs look nice but be carefull, the output is only 500 mA. The S7 charger is a 2amp output charger. I'm not sure how well it will run on a lower input.
Ives
Click to expand...
Click to collapse
The DC pack will only feed what the unit draws, and I doubt very much that it draws the entire 2000mA.
I have rigged up a USB charging cable for myself, USB pumps out 5v at 500mA max per port (I'm only using 1) and it charges a little slower than from the wall, depending on which computer I'm charging from, but apart from that it works great still and I can use the same cable to charge from other USB-charging devices like the one I have in my car.
The 500mA output will just mean it charges slower, and seeing how it's only a battery extender (IE, the oem battery is still required) and not a charging solution (the S7 can run without the battery off only the charge from the wall), the charge provided will be fine for extending the battery life.
davidcampbell said:
The DC pack will only feed what the unit draws, and I doubt very much that it draws the entire 2000mA.
I have rigged up a USB charging cable for myself, USB pumps out 5v at 500mA max per port (I'm only using 1) and it charges a little slower than from the wall, depending on which computer I'm charging from, but apart from that it works great still and I can use the same cable to charge from other USB-charging devices like the one I have in my car.
The 500mA output will just mean it charges slower, and seeing how it's only a battery extender (IE, the oem battery is still required) and not a charging solution (the S7 can run without the battery off only the charge from the wall), the charge provided will be fine for extending the battery life.
Click to expand...
Click to collapse
500mAh as supplied by standard USB will charge but as you say only slowly.
It will not start a charge if the battery has been allowed to drop too low. That's common with all Lion batteries and is why you get a high current wall charger to do the job.
If you are using the device at the same time (and depending on the functions in use and the state of charge of the battery) you will definately struggle with any positive charge and will experience heat build up in the USB port, cable and device so be carefull!
If you are also using the device as a phone and get a call there will be an extra high peak current draw that has to be contended with and that complicates things further.
With all the tests that I have done allong these lines 1000mAh is a bare minimum to cope with eventualities and even then it's borderline.
I have blown car adapter fuses and had low current phone chargers get really hot.
I now only use 2000mAH rated chargers.
Are there any? I would really want to have a battery that could last at least 6 hrs... Any suggestions?
Stjom said:
Are there any? I would really want to have a battery that could last at least 6 hrs... Any suggestions?
Click to expand...
Click to collapse
Energizer XPAL XP18000
That will give you about an extra 12-18 hours,
But no internal battery larger than standard. Why would you want one when the external packs are usable with any device and don't become redundant when you upgrade to a different model?
I made such a battery of two packages of Chinese Tablet battery voltage of 7.4V LiJon / 1500mAh connected in series and used a converter on the circuit LM2576 (with car charger navigation) [//chomikuj.pl/wibi) -> Huawei Ideos S7/Dodatkowa bateria]. This additional charger to recharge your battery voltage 8.4V. Pictures and diagrams from the following link will explain everything.

[Q] clarification about USB vs AC charging: battery life

i'm reading different opinions about this when i searched through the xda forums and on google.
i'm using the same custom rom and kernel for about a week now. a few days ago, i charged purely on wall socket. left overnight, my battery lost only 2%.
last night, i charged my phone when it was about 30%. i charged using usb up to 85%, then i finished it off on AC up to a 100%. my overnight loss went up to 5% (i did not install any additional apk, or change my setcpu profiles, etc).
there are no topics on this, specifically for SGS2. mostly are from HTC threads.
from what i learned, usb's only pour out about half of what AC's can give (500 mah vs 1,000 mah). does that translate into a poorer batt life?
How you charge your phone, usb vs AC will not effect the battery life, 100% is 100%, it will just charge slower via usb.
Sent from my GT-I9100 using xda premium
I have noticed something similar with my captivate.I would guess that when you use the wall charger with 1amp the battery gets more of a charge than when you use a usb charger at .5amps. 1amp can cause more chemical change in the battery than half an amp.
sent from my Infuse at Tranquility Base.
SGS2 will only let 650mA into the battery, AFAIK it's hardware restricted to do this. Wall charger will charge faster, but only slightly.
I see no difference and 2% to 5% is within a tolerable variation of overnight drain .
Its all the same electricity .
jje
Sticks02 said:
SGS2 will only let 650mA into the battery, AFAIK it's hardware restricted to do this. Wall charger will charge faster, but only slightly.
Click to expand...
Click to collapse
Firmware, actually, and the phone determines how much it will draw based on the resistance between the two USB data pins. If the resistance is < 200 ohms, it assumes it's plugged into an AC charger, and will draw up to 650 mA. Otherwise, it assumes it's plugged into a PC's USB 2.0 port, and will draw up to 450 mA, just under the 500 mA that a USB 2.0 port is supposed to provide, per the USB 2.0 spec.
Since it's firmware, it should be possible to change the current draw by re-compiling the kernel sources with new values. Note that you don't want to go too high on the charging current, as that could cause overheating or fire.
Sticks02 said:
SGS2 will only let 650mA into the battery, AFAIK it's hardware restricted to do this. Wall charger will charge faster, but only slightly.
Click to expand...
Click to collapse
And how about charging a spare battery using a separate battery charger?
I have two batteries and I never charge them plugging the phone, just using a spare battery charger. Does it have any negative effect on the batteries' lifespan?
dont know what happened but my phone is being charged with ac adapter as same speed as usb.(more than 4 hours) :S
I have a USB charger capable of delivering 1A.
Even with the data pins shorted (phone side), it still seems to draw only 350 mA :-(
Any ideas?
Known made-up cables that do work?

Is it possible to see how many Amps of power are being provided?

Just curious if there is an app or something similar that would show how many amps are being provided when charging through a wall charger/USB powered hub? The reason I ask is that I'm thinking of buying a powered USB 3.0 Hub. The adapter that came with our phone says it's 2 Amp, so I am assuming our phone can pull 2 amps for charging. Just wanted to verify in some way that a 2 Amp dedicated port would really work for this phone.
*Madmoose* said:
Just curious if there is an app or something similar that would show how many amps are being provided when charging through a wall charger/USB powered hub? The reason I ask is that I'm thinking of buying a powered USB 3.0 Hub. The adapter that came with our phone says it's 2 Amp, so I am assuming our phone can pull 2 amps for charging. Just wanted to verify in some way that a 2 Amp dedicated port would really work for this phone.
Click to expand...
Click to collapse
When I get home, I'll download the kernel source and see if I can find out how much power it draws during charging. I doubt however, that it will draw 2A during charging as most chargers are rated to supply more power than the phone will accept.
Yeah, 2A seems like that could melt a battery charging that fast. Someone sent me a private message and told me to try CurrentWidget. I threw that on the phone and it registers as 1A while charging. But it appears like the widget doesn't break it down with decimals. For instance it could be charging with 1.8A and wouldn't know it. I put it in a standard USB port and it reported as charging with 0 Amps but the battery was indeed charging.
I took a quick look at the N7100 (International Note 2) source posted on Github by CM and it looks like AC charger is 650mA, USB is 450mA. It's a little hard to tell what exactly it's using for charging, so I'll try to verify that when I get home and have a chance to take a better look.
*Madmoose* said:
Yeah, 2A seems like that could melt a battery charging that fast. Someone sent me a private message and told me to try CurrentWidget. I threw that on the phone and it registers as 1A while charging. But it appears like the widget doesn't break it down with decimals. For instance it could be charging with 1.8A and wouldn't know it. I put it in a standard USB port and it reported as charging with 0 Amps but the battery was indeed charging.
Click to expand...
Click to collapse
A 3100mAh Lithium Ion battery can easily handle a full 2A charge rate. The ideal charge profile for Lithium Ion is a CC/CV profile, starts at constant current between like 3V and 4V, which most LI batters can take a rate of 1C, meaning it can handle a charge rate of 3.1A, recommended charge rate to achieve the most possible charge/discharge cycles is usually 0.2C so for a 3100mAh battery that would be 620mA. Once the charge gets to the correct voltage it gets to constant voltage and charges until termination current usually in the 100mA range. So yes, it can handle a 2A charge no problem.
Hey there. I very much appreciate that breakdown. Makes me wonder why they dropped the amps so much during charge.
bose301s said:
recommended charge rate to achieve the most possible charge/discharge cycles is usually 0.2C so for a 3100mAh battery that would be 620mA.
Click to expand...
Click to collapse
If this is true (first time I've seen this anywhere), that would line up great with the 650mA max charge rate I found. Also, I downloaded the VZW source, and it doesn't look to significantly different from the N7100 source, at least as far as the charger stuff is concerned, so I would say they both probably have a max charge rate of 650mA.
I appreciate the info and time you both put into this. I guess it means a 2A usb port will be slight overkill. Even changing the charge rate to a higher value seems to indicate a lower battery life. Makes you wonder how apple did it's math for the ipads charge rate. The battery must be huge to accommodate a 1.1A charge rate. Or they are sacrificing battery life for fast charging.
Wont the kernel dictate the charge rate no matter what the charger is rated at?
If the kernel is set for a charge rate of 650mA (0.650A), then why does the Note 2 have a more powerful 2A wall charger, while the GS3 has a 1A wall charger.
FAUguy said:
If the kernel is set for a charge rate of 650mA (0.650A), then why does the Note 2 have a more powerful 2A wall charger, while the GS3 has a 1A wall charger.
Click to expand...
Click to collapse
The original nook color 7" came with a 2A wall charger and that was 2 years ago... both my note 2 and nook color charge about the same rate (quick to 99% and slow to 100). The charger is probably cheaper to make at 2A rather than anything and plus it could be used to charge future devices. Also if you used a 1A charger to charge the note it might possibly get warm/hot from running at near full capacity.
Im using my OLD blackberry 700mA wall charger to charge the phone at night while im sleeping. No problems with heat.

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