A week or so ago I got a good deal on a nice solar charger, but was rather surprised at how ineffective it was at charging my Kindle Fire. The charger is basically a 4,000 mAh battery coupled with a 1.4 W solar panel, and puts out 1 A at 5.5 V. The Kindle, has a 4,400 mAh battery and can charge at up to 1.8 A (per the adapter), so I figured the two would be a good match.
Sadly, I only got about a +30% charge for the Kindle while depleting the charger. My first thought was that the 4,000 mAh charger battery really was too good to be true at that price, so I tested it with my phone's external battery charger, and got 2540 mAh of charge plus several hours of trickle charging between batteries.
Doing some research, lithium ion batteries have 80-90% charge/discharge efficiency, and charging efficiency is 97-99%. The charging circuits between the two batteries also must pull from these figures. So, 2,540 mAh and a fair bit of trickle charging seems reasonable for a 4,000 mAh battery to supply another battery. That's 80% minus 660 mAh of wasted charging/other inefficiencies.
Now, came the question of why my Kindle is getting less than half of that. Feeling that the charger was getting warm, I figure that the Kindle is taking advantage of the full amp offered, and perhaps more (I may have to catabolize some cables and rig up my multimeter to be sure). Furthermore, there is no way to charge the Kindle when it's powered off, so you get a constant drain from that (on AC power-management settings, no less).
To test that latter concept, I left my 95% charged Kindle on the charger last night, and it completely drained the charger in about 15 hours. This seems quite high for the power consumption of an idle device, but I'm sure it "thinks" it's on AC and there's little reason to conserve. Which explains why I'm getting such poor performance for my external charger. Or so I think...
All that said, does this mirror other people's experiences?
Related
Hi,
After feeling that something wasn't right with my HP Ipaq HX4700 running time I have decided to look into whether there is a problem.
I have now tested 2 batteries in my HX4700 and just need someone with some *knowledge* to give me some advice on my findings.
1st battery tested is an aftermarket Panasonic extended 3900mAh (assembled in China with Japan cells) with battery cover.
2nd battery tested is the original HP standard 1800mAh battery.
I set the HX4700 W2003CE (sp29841 with sp30939 update) with backlight approx 70% (my usual setting), all auto-off features disabled (backlight/standby), wifi / bluetooth / irda off, TCPMP player playing mp3 continuously from 100% charge until battery reached 10% left.
For measuring battery drain I used acbPowerMeter.
After completely tests of both batteries here are my findings;
Estimated length of test to reach 0% power remaining equaled 5 hours, mAh total drain 1800mAh;
Average drain was 355mA to 360mA
after 3/4 hours 250mAh used 85% power remaining
after 1 hours 350mAh used 80% power remaining
after 1 1/2 hours 500mAh used 70% power remaining
after 2 hours 700mAh used 60% power remaining
after 2 1/2 hours 900mAh used 50% power remaining
after 3 hours 1100mAh used 40% power remaining
after 3 1/2 hours 1250mAh used 30% power remaining
after 4 hours 1450mAh used 20% power remaining
after 4.5 hours 1600mAh used 10% power remaining
after 5 hours 1800mAh used 0% power remaining (This one is the estimate)
Getting the above test results from both batteries shows something is definately wrong!
I am happy that the HP standard battery is working correctly reaching it's 1800mAh potential.
I am shocked and upset that the Panasonic extended battery is only working like a standard battery.
1800mAh is lower than 50% of the Panasonic's 3900mAh batteries potential capacity.
Based on 355mA to 360mA average drain the 3900mAh battery should last around 10 3/4 hours!!!
Any ideas what I can do with the Panasonic extended battery now, or can only the batteries manufacturer fix it?
I have checked and the battery is still under warranty for another 5 months.
Thankyou,
Dan
Battery has been replaced under warranty.
Battery has been replaced under warranty.
Was quite a process but after two weeks of being stuffed around I got angry with the supplier and I was sent a replacement.
I have not used or tested the replacement battery as I have decided to sell the battery 'as new' condition.
I have also sold my HX4700 now. It was a great device and I may regret selling it in the future.
Fingers crossed I will find another device that is a worthy successor.
In conclusion; Li-Ion batteries 'life span' is measured from the date they are manufactured not the date you purchase them. This means that a supplier with old stock may sell you a battery that is half dead. So take this as a warning of what can happen. I recommend checking a 'manufactured date' if possible to save from disappointment before purchasing. If you do get a battery that is half dead then under the consumer guarantees act you should be able to return the battery within the warranty period. Some suppliers are now stating that if a battery looses 20% or more 'life' in its first year of use they will replace the battery.
Thanks for looking.
Side note; Charging mAh???
I am currently charging my extended battery again.
Just noticed that with my HP 2A wall charger connected to my HP cradle it is only reading approxiamately 1000mA charging current via acbPowerMeter.
Shouldn't that be 2000mA? Is it because I am going through the HP cradle?
edit #1;
Just disconnected the wall charger from the cradle and plugged it directly into the HX4700. It still is only reading approxiamately 1000mA charge current.
edit #2;
Battery is now at 80% charge and charging current has decreased to 600mA. I guess the charge current decreases as the battery fills up.
Just connected a HP 1A wall charger directly into the HX4700 and is reading 600mA charge current as well.
Makes me wonder if paying extra for the 2A max output charger was worth it???
Any explanations, advice?
I will be quite annoyed if I found that the 1A and 2A chargers both took the same amount of time to charge the batteries. Ofcourse I am suppose to be looking at testing running time of batteries at the moment not charging, maybe that could be after..
Edit;
I will see if I can find out if the HX4700 limits the charge rate to 1000mA. If so, then HP is ripping people of with 2A chargers that will never be utilised beyond what the standard HP 1A charger can do.
Do you think the charge rate may have been programmed into batteries onboard chip by the batteries manufacturer as opposed to the HX4700 being the limiting factor??
Thanks,
Dan.
Hey everyone,where I can buy orriginal battery for my XDA IIs (blue angel),my position in Indonesia (samarinda - east borneo). I need it immidiately.
http://forum.xda-developers.com/showthread.php?t=478519
Sorry orb3000 doesn't help
orb3000 said:
http://forum.xda-developers.com/showthread.php?t=478519
Click to expand...
Click to collapse
No help sorry, the HP HX4700 has no phone functions.
May help others though.
Thread is now concluded
I have now finished updating/monitoring this thread.
Conclusion can now be seen in post#2 above.
If anyone wants to ask me a question or contact me please send me a PM.
I don't have much time to spend in this forum so response to communication will take a long time.
Hi,Everyone,
Unfortunately, quite a few iPAQ hx4700 owners noticed a huge reduction in how long their device's battery would last.
You see, ROM update 1.10 introduced an error where the hand held would think its battery was empty when it wasn't.
So I just ordered this charger and it charged my phone from 4% to %100 percent in exactly 3 hours!
http://www.amazon.com/gp/product/B0051ZJA64/ref=oh_o00_s00_i00_details
Wow, what a great improvement over stock which takes 6+ hours. This makes me believe, that even though the stock output is rated at 1000ma and this charger's output is only rated 700ma that this charges works correctly!
If you have a 1800mah battery and you charge it at a rate of .7A, it should take it exactly 2.57 hours to charge, (1800/700). With stock it should take less, because 1800/1000 = 1.8 hours, but it takes 6+ hours to fully charge! Something is f'ed up with the stock charger or phone's software...
Yeah. About that. I just got my E4GT yesterday and noticed it does charge extra slow compared to my O.G. Epic.
My wife stayed with hers, maybe I will try charging my phone on hers. I wonder if that would make a difference...
Android Amateur said:
Yeah. About that. I just got my E4GT yesterday and noticed it does charge extra slow compared to my O.G. Epic.
My wife stayed with hers, maybe I will try charging my phone on hers. I wonder if that would make a difference...
Click to expand...
Click to collapse
At first my charging was extremely slow but now it'll charge from 2 to 100 in under three hours
Sent from my SPH-D710 using xda premium
I use the Palm charger from my TouchPad. Will go from dead to fully charged in about an hour and a half.
What's you TouchPad charger's output in mah? I think I might have to splice into a spare USB cable and check how much current is actually used by phone when on stock charger...pretty sure it is nowhere close to 1000mah.
2000mah is the output from the TP charger.
According to BatteryMonitorWidget, it estimates avg mA charging at 270mA using the stock charger that came with this particular phone.
I have my original charger from my Evo 4g and have noticed that it charges my phone a lot faster then the stock one that came with the phone. :-( weird
Sent from my SPH-D710 using Tapatalk
sfhub said:
According to BatteryMonitorWidget, it estimates avg mA charging at 270mA using the stock charger that came with this particular phone.
Click to expand...
Click to collapse
That sounds about right! I'll see if I can test this with my AMP meter tonight and tell you all for sure on stock vs new samsung charger that I've got.
awesomeindeed said:
2000mah is the output from the TP charger.
Click to expand...
Click to collapse
Yeah, at 2000mah it should charge in less than one hour...I would say your actual charge current to be around 1200mah...
i would be careful with these chargers.
i have dealt with a lot of Li-Po's in the past and there was a formula to how fast you should charge them.
i imagine it is the same deal with Li-On.
charging outside such formula could kill the life of your battery or worse.
Seems like i must have gotten lucky as a ton of people are having problems with their phone or chargers.
I just charged my battery from 0 to 100% off the stock charger in 2 and a half hours and i also havent gotten any of the dodgy input problems using the phone while charging.
I went back and took a longer look at the battery history when charging. When starting the charge at 65% it starts off around 828mA, then 540mA, then 360mA, so it looks like (as expected) the phone knows how much current to pull to charge the battery safely and it adjusts based on how full the battery is. Not saying it does this for the charger included with your phone, but that is the behavior for the charger included with this phone.
These are all estimates provided by Battery Monitor Widget because there is no real-time mA current meter in this phone (according to the author)
Ordered one of these. Stock charger takes a lifetime to charge the phone.
My GF got Nexus S 4G and it's stock charger also takes 6+ hours to charge, so there's something wrong with the chargers I guess...
The pins on this charger must me different than the stock charger. Just because the stock charger is rated up to 1Ah doesn't meant the phone or batteries circuitry allows that much output. The resistance and length of the USB pins on the cable are what determines the output of the charger. Simply using a different USB cable with the stock charger will get you faster charge times.
Using a 2Ah charger will get you nowhere, the circuitry doesn't allow that strong of a current. Just a bit of an FYI. Save your money and save your phone, use a different USB cable.
Also, how is the charge time holding up? I doubt you're getting a saturated charge with that charger.
SpaceMonky said:
i would be careful with these chargers.
i have dealt with a lot of Li-Po's in the past and there was a formula to how fast you should charge them.
i imagine it is the same deal with Li-On.
charging outside such formula could kill the life of your battery or worse.
Click to expand...
Click to collapse
Ive dealt with 1,2, and 3 cell lipos ranging from 150mah to 5000mah, and every one of them either say to be (or ive been told its recommended to do so) charged at 1C. so a 500mah battery should be charged at .5A, 1000mah at 1A, 5000mah at 5A, etc...
my lipo charger displays a bunch of info as the battery charges and it definitely drops the current as the battery gets closer to being fully charged. if its the same with li-on then I would imagine that .18A should be the most you would charge this battery, but Id rather it take a long time because unless things have changed recently, doesnt the slower you charge the battery prolong its life cycle as well as extend how long it lasts each charge? I only charge mine at night when I am sleeping so who cares if it takes longer than an hour. if I get into an emergency situation I have the cig lighter charger and in the worst case I even have one of those crank flashlights I can use to charge the phone in the event my car battery shorted out or something...
I've notice many ppl discuss about their aftermarket battery were unable to
reach 100% when using standalone aftermarket charger.
Just to point out that the S3's battery is using 4.35v cell instead of the usual 4.2v cell.
Most standard charger stops at 4.2v thus they'll stop at around 90%.
If you're looking for standalone charger. Best to look for charger rated at 4.35v.
(I rooted and change kernel to undervolt the CPU. the result is excellent, anyone who want longer run time should do it)
Every charger is 5 volts. The phone sets the charge voltage, not the charger, which is 5 volts.
The OP is referring to the voltage of the battery cells, not the USB charger (which is always 5V). The battery on the GS3 is in fact a higher voltage than most other phones (like the GS2). If you use an offline/standalone battery charger that does not charge to the full voltage of the GS3 battery the battery will show about 90% charged when you place it in the phone.
i wrote a review a few days ago on a stand alone charger i bought.
so far no problems with it charging my battery to 100%.
http://forum.xda-developers.com/showthread.php?t=1924706
I have an LG Lucid which isn't half bad. Unless you factor in battery life.
So I'm ready to pull the trigger on a spare battery or two, as well as a wall charger. You know those ones that you plug the battery into itself.
Anyone have recommendations on an inexpensive, decent charger that will charge a 1800-1900mah battery within maybe 6 hours or so?
Thanks!
Oh- looking on amazon if I can, as I have a gift card.
I just did this for my S3.
I can't recommend one for your phone, but once you know what to look for, it's the same basics across all batteries and chargers.
Do you want it to charge slowly ? You say 6 hours, but that seems awfully slow to me. Is that the point - so you can leave it on overnight ? I have a charger that chargers my 2200mAh battery in ~4 hours.
Look for a charger that will charge at 600+mAh. Often it will charge faster if connected to USB. You want to avoid the ones that charge as slowly as 300mAh. I guess they're good if you want to leave something overnight, but they're going to take ~8 hours to charge the battery !
Anyway - no matter if you want it to charge fast or slow, just look at the mAh output and do the math compared to your battery capacity - you can even use a "calculator" that will do the math for you (but it's really easy - "2200 / 600 = 3.6" - so 3.6 hours, but with some wiggle room for lower than 100% efficiency).
I got mine from the brand Anker - they were one of the few that offered a charger that wasn't ridiculously slow. It's 600mAh from an outlet, 1000mAh from USB (meaning it could charge the battery almost twice as fast). It came with two spares and the charger. All the reviews I read didn't say great things about the "universal" chargers, and they all seemed to have lower rates of charging - but maybe I wasn't looking at the right ones.
I'm curious if anyone has been using Qi charging with their TabPro? Anyone's comments would be appreciated.
I used a micro-usb Qi coil receiver between my TabPro 8.4 and the Poetic case for a few weeks without issues.
But then something happened to cause the Qi charging pad to overheat. I ended up having to have the TabPro 8.4 replaced by BestBuy as the TabPro would no longer charge at all, even trying different micro-usb cables and 2.1 amp power adaptors. What was even stranger, was the battery continued to drain even after powering the TabPro off! I'm puzzled as to what was damaged, but the end result was the battery went from 41% charge to 7% charge overnight even though it was powered off (not sleeping, but powered off) and not connected to a charger. When I discovered it was at 7% I removed my account info, but even with the charger plugged in, the battery went down to 3% while working on the TabPro. When I checked on it an hour latter it was dead. If I plugged in the charger, after about 20 seconds it would flash the green battery for about a second, then it would go out. No boot, no charging, even after leaving it charging for 24 hours.
So I'm very reluctant to try to use Qi wireless charging on my replacement tab. I suspect the Qi charging pad failed and overheated. There is a spot about the size of a dime where the plastic partially melted on the charging pad. The Poetic case and the TabPro look fine, and the charging pad still acts like it is working. Very puzzling. Any ideas or cautions?
ron12 said:
I'm curious if anyone has been using Qi charging with their TabPro? Anyone's comments would be appreciated.
I used a micro-usb Qi coil receiver between my TabPro 8.4 and the Poetic case for a few weeks without issues.
But then something happened to cause the Qi charging pad to overheat. I ended up having to have the TabPro 8.4 replaced by BestBuy as the TabPro would no longer charge at all, even trying different micro-usb cables and 2.1 amp power adaptors. What was even stranger, was the battery continued to drain even after powering the TabPro off! I'm puzzled as to what was damaged, but the end result was the battery went from 41% charge to 7% charge overnight even though it was powered off (not sleeping, but powered off) and not connected to a charger. When I discovered it was at 7% I removed my account info, but even with the charger plugged in, the battery went down to 3% while working on the TabPro. When I checked on it an hour latter it was dead. If I plugged in the charger, after about 20 seconds it would flash the green battery for about a second, then it would go out. No boot, no charging, even after leaving it charging for 24 hours.
So I'm very reluctant to try to use Qi wireless charging on my replacement tab. I suspect the Qi charging pad failed and overheated. There is a spot about the size of a dime where the plastic partially melted on the charging pad. The Poetic case and the TabPro look fine, and the charging pad still acts like it is working. Very puzzling. Any ideas or cautions?
Click to expand...
Click to collapse
The only thing I can think of is maybe the Qi charging pad failed to deliver 2.1 Amps to correctly charge it (I don't think they even make 1 Amp coils yet? - though I could be wrong.) , maybe the tab went into charging mode but it was really discharging since not enough current was going in that it needed to charge + keep the tablet running so in the end maybe it destroyed the battery since it went completely flat which is usually a bad thing for l-ion battery's
Usually when android says the battery is at 0% the battery really has about 20% remaining for protection of the battery and preventing it from going completely empty (l-ion can really be drained to 2.5v but android reads 0% around 3.4v or 3.2v if i remember correctly as protection from flat-lining the batt), however if it was under charging mode I'm sure it would override this as it thinks it's plugged in so it's not paying attention to the battery, but really the batt is draining to compensate for the underpowered charger, that would be my guess maybe constantly using the Qi charger the battery circuitry changed the battery status from lv 2 (good) to ~ lv 4 (bad) since it wasn't receiving the current it was supposed to and the circuitry thought something was wrong with the battery cells or the battery just went bad since it was always under a charging / discharging state never reaching 100%.
on a side note
I found this tablet to be very fussy when using other chargers then its official one, I have tried several chargers and they just dont function like the stock one for example
HP Touchpad charger 5.3v - 2.0A - Very high quality charger and even won some awards for beating out other chargers - I found this would sometimes not fully charge the tablet to 100% it would idle around 98% (I have two of these chargers) - Charge current starts around 1800 mAh drops to 200 mAh when battery gets full don't think its enough to top it off. (charges at 5v)
10,000 mAh Power-bank (5v , 2.0A), found out this would not fully charge the tablet either it would get to 80%, upon further inspection the 2A port was only delivering about 1 Amp of current according to my amp reader (voltage drop to 4.98)
Samsung official charger (5.3v 2.0A)- though seems to start at a pretty high 5.60 volts (higher then other chargers) , and charges at about 1870 mAh , always reaches 100% with this charger. (I have two of these chargers since I bought another one as backup - both do the same thing)
otyg said:
The only thing I can think of is maybe the Qi charging pad failed to deliver 2.1 Amps to correctly charge it (I don't think they even make 1 Amp coils yet?
. . .
Usually when android says the battery is at 0% the battery really has about 20% remaining for protection of the battery and preventing it from going completely empty (l-ion can really be drained to 2.5v but android reads 0% around 3.4v or 3.2v if i remember correctly as protection from flat-lining the batt), however if it was under charging mode I'm sure it would override this as it thinks it's plugged in so it's not paying attention to the battery, but really the batt is draining to compensate for the underpowered charger, that would be my guess maybe constantly using the Qi charger the battery circuitry changed the battery status from lv 2 (good) to ~ lv 4 (bad) since it wasn't receiving the current it was supposed to and the circuitry thought something was wrong with the battery cells or the battery just went bad since it was always under a charging / discharging state never reaching 100%.
on a side note
I found this tablet to be very fussy when using other chargers then its official one, I have tried several chargers and they just dont function like the stock one for example
HP Touchpad charger 5.3v - 2.0A - Very high quality charger and even won some awards for beating out other chargers - I found this would sometimes not fully charge the tablet to 100% it would idle around 98% (I have two of these chargers) - Charge current starts around 1800 mAh drops to 200 mAh when battery gets full don't think its enough to top it off. (charges at 5v)
Click to expand...
Click to collapse
That could be the case. Yet, for two weeks, the Qi charging had no problems taking the charge to 100%. It would charge a bit over 15% an hour. The Galaxy Charging Current app reported between 670 and 750ma charging current using Qi charging.
At this point I'll likely never know, but it could be the battery itself simply failed on the tablet. My question is mainly to see if anyone else has used Qi charging, and what their experience is. How can I display the battery status (you referenced lv 2 (good) to ~ lv 4 (bad))? The battery app from the Play Store does display "battery health" but I've only seen it say "Good".
On your side note, I occasionally plug the tablet into the USB port on my computer (measures 5.10V), and it charges at about 10% an hour while sleeping, and has repeatedly charged the battery to 100% when I leave it connected. I have an EnrePlex Jumper Prime 4400mAh that measures 5.18V, and charges at 1.5A. It has charged the battery to 100%, though will run out of juice if the battery is lower than 40% before I use it, it measures 5.18V.
I have an old Galaxy Tab 2 10.1 that I often charge via the computer's USB port, although it takes a long time, and it's battery is still fine after almost 3 years.
ron12 said:
That could be the case. Yet, for two weeks, the Qi charging had no problems taking the charge to 100%. It would charge a bit over 15% an hour. The Galaxy Charging Current app reported between 670 and 750ma charging current using Qi charging.
At this point I'll likely never know, but it could be the battery itself simply failed on the tablet. My question is mainly to see if anyone else has used Qi charging, and what their experience is. How can I display the battery status (you referenced lv 2 (good) to ~ lv 4 (bad))? The battery app from the Play Store does display "battery health" but I've only seen it say "Good".
On your side note, I occasionally plug the tablet into the USB port on my computer (measures 5.10V), and it charges at about 10% an hour while sleeping, and has repeatedly charged the battery to 100% when I leave it connected. I have an EnrePlex Jumper Prime 4400mAh that measures 5.18V, and charges at 1.5A. It has charged the battery to 100%, though will run out of juice if the battery is lower than 40% before I use it, it measures 5.18V.
I have an old Galaxy Tab 2 10.1 that I often charge via the computer's USB port, although it takes a long time, and it's battery is still fine after almost 3 years.
Click to expand...
Click to collapse
The battery app from the play store probably does the same thing just shows a status as a replacement of the health, you can see the status with logcat occasionally you will see something like this ---
you might need root for some of these commands., you can use Terminal Emulator , adb shell, or sshd to access these commands.
Logcat::
1.
"D/BatteryService( 934): level:83, scale:100, status:3, health:2, present:true, voltage: 4091, temperature: 234, technology: Li-ion, AC powered:false, USB powered:false, Wireless powered:false, icon:17303447, invalid charger:0, online:1, current avg:-378, charge type:0, power sharing:false"
2. (shell)
dumpsys battery
will output something like this
Current Battery Service state:
AC powered: false
USB powered: false
Wireless powered: false
status: 3 < - unplugged
health: 2 <- health:2 would translate to good , health 1 would be excellent (though I have never seen a 1 status , 3 poor, 4 bad
present: true
level: 83
scale: 100
voltage: 4114
current now: -140
temperature: 248
technology: Li-ion
3. (shell, you can check out other files in the /sys/class/power_supply/battery/directory but be careful not to modify them)
cat /sys/class/power_supply/battery/health
Good