Will this kill my phone? Using the "D-Link" "AF 1805-A" as a cellphone charger.. - Page 1
Forum section: electronics / beginners

author: Benxd10
author_rank: Newbie
timestamp: February 19, 2017, 12:46:00 am
content: In this instance specifically: I don't want to spend much or any money if I don't need to.I have had purchased a few micro USB cables from monoprice.com and they only charge my phone, battery banks,ps4 controller at a rate of 0.5 Ampers @ +5 Volts.I have verified that using a multimeter.So I was wondering if using the D-Link AF 1805-A is a good idea to charge my phone or will it kill my phone and then my parents would be upset with me.I have already tried the converted D-link adapter with some cheap devices and it appears to work well.I even tried it on my HTC ONE M7 for a few minutes and it worked. Unfortunately, while I was stressing out my phone with a program while using the D-link brand wall wart on my HTC ONE M7 my cellphone's battery percentage was decreasing by one percent every 10 minutes.If I had to guess why it wouldn't work would it be related to power conversion tolerances such as the adapter may output wired spikes of energy, that I can't detect without an oscilloscope, that would heat up or overheat my phone's equivalent "VRM".D-link AF 1805-A Specs:+5v @ 2.5 Ampers(manufactured by "Jentec Technology)

author: Rick Law
author_rank: Super Contributor
timestamp: February 19, 2017, 02:28:50 am
content: I am a hobbyist and not an expert to any degree, but let me share what I know.re: Battery dropping while "charging"The amperage going into the phone is low.The phone is burn up more power than the power coming invia the charging cable, so it need to get additional power from battery so the battery keeps dropping.It may be the charger, the cable, or both. There are three issues I can think of there:Cable(1) The construction of your cable may simply not be able to carry much amperage. So, it needs to get some more from the battery to keep itself going.Cable or Power Source(2) 500mA is the USB limit as defined by USB standard. For the device (phone) to draw >500mA (which may mess up your PC's USB), the device needs to know it is connected to something that can give > 500mA. Different manufacturer uses different techniques to say: "I am a power source". Recent standard has D+ short to D- as a method of doing just that. You can research that further for your phone to see what method it uses. D+ short to D- seems a good bet but you have to find out for sure.(Pretend your phone follows the D+/D- standard) Once your phone sees D+ shorted to D- then it will draw > 500mA. If not, it will/should draw below 500mA. Many tasks can consumes more than 500mA, so instead of charging, you are still taking from the battery.The phone's factory supplied power source will set up properly for the phone to know it is connected to the charger. The DLINK power brick doesn't have such setup.Power Source(3) Your power brick may be able to supply enough current, but if your brick's output voltage dips too much, your device will/should reduce current draw.My ASUS phone will throttle down current very quickly. It (when near empty) will draw about 1.1A from the ASUS 1.4A supply. When I use a different (Kindle 2A) charger on it, the 1.1A draw drops the output voltage to 4.8V briefly. That drop triggers my phone to reduce current by about 30% typically. So -counter intuitively, my 2A charger actually will put less into the phone than my 1.4A charger- all because of poor load regulation (load dropping the output voltage down).So, this 2.5A power brick you got, if high current draw causes it's voltage to drop, your phone may end up taking less.Bottom line:Your power brick, if it is not wildly swinging (ie: it is close to 5V) should work fine up till at least 500mA. Your phone may detects what it connects to before it decides how much current it draws. In that case, you will need to research how your phone does it. Tie D+ to D- is a good bet.2.5A is a lot for USB cable/plug/phone, I bet your phone wont take that much. If it does, your plugs may not make it. The contacts may heat up a lot. (I had a connector's plastic housing melting from heat at 4Amp once - the fuse spring turned into heat coil and burned the spring's wire-image on the the plastic housing. I caught it before it melted through). So,if you get it to draw > 1.5A, watch out. There may be danger there.Good luck and hope this helpsRick

author: Benxd10
author_rank: Newbie
timestamp: February 19, 2017, 02:53:44 am
content: I understand now why my phone's battery was losing power.I kinda knew about the D+ and D- and how it affects how devices charge.For instance, this D-Link charger I have created doesn't charge my Ps4 controller because it simply lacks the D+ and D- pins.I also understand the concept of current limiting when voltage dips due to resistance.Would it be smart to add a specific fuse that would trip or create an open circuit when the current or voltage goes above the norm?Thank you, Rick Law for taking time out of your day to enlighten me.EDIT: I forgot to mention that My new D-link charger's cable is 63 inches @ 18 AWG and at the end, it is, less than one inch @ 22/24 AWGI think that the resistance equates to roughly 0.34 ohms , although not accounting for the resistance of the connector(micro USB).

author: Rick Law
author_rank: Super Contributor
timestamp: February 19, 2017, 05:21:06 am
content: First - I just said "not wildly swinging (ie: it is close to 5V) should work", I did not emphasize it enough.Do you have a DMM? You should find out how manyvolts your DLINK plug is giving out. All the DLINK power bricks I got are regulated, but just in case... If it is unregulated, it could be giving a hell of a lot more than 5V.Anything over 5.4V, it is not a good thing. It may kill your phone.Best would be within 5% of 5V.Second, you're welcome...re: "Would it be smart to add a specific fuse that would trip or create an open circuit when the current or voltage goes above the norm?"A fuse is a good thing, but it will only protect on over current and can't protect against over voltage. Second, each fuse will end up causing some voltage drop. A 1.5A fuse would not be a bad thing. I very much doubt your phone would pull that much current, but a fuse is not a bad idea.Third, since your plug doesn't have D+/D-, it is not a data cable plug. Which leads me to wonder, what plug is that? Could that anUSB-OTGplug. USB-OTG makes that socket a host socket - meaning, you can connect other USB device to it like an sd card reader but that too needs D+/D-. Either way, If it is a plug from an OTG cable,your phone would actually put out power on that USB-OTG pluginstead of taking power in! You can use an OTG cable to use your phone to power an LED reading lamp for example.You should first check what voltage the power brick puts out. That is most important. if it is 5V-ish, it is safe to try other things.Then, if you have a means to measure current, you can actually see how much is flowing into the phone. If you do not have a means to measure current, try the App "Ampere".Great little appfor what you need. If that app is compatible with your phone, it will help you. I think the author is also a forum member here. If will tell you approximately how many Amps are going into your battery.Start the app before you plug in your home-made recharger. It should show how many mA your phone is chewing up. (Let say 400mA, the App will show -400mA) Once you plug in your charger, it move that number to +100mA if your setup is able to give it 500mA. The number varies and accuracy is not high, but it will give you an idea.Again, first check how many volts your power source is really giving.Don't go further if it put out more than 5.4V, it is not safe.Lets do that first before we move further.Rick

author: Benxd10
author_rank: Newbie
timestamp: February 19, 2017, 07:21:56 am
content: I used this exact cable for this mod.https://www.monoprice.com/product?p_id=13924Alright, so I have tested this modified adapter, for a few hours, with a "cheap" or value battery bank I made a while ago, It has 12 18650 cells in it that are in parallel and takes over 24-48 hours to charge because it has one cheap 1 amp charger/regulator.The D-link adapter Produces +5.19 Volts under a "no load" situationWith the D-link charger plugged into my battery bank it produces these results:+5.06 Volts @ 0.55 Ampers(initial)+5.06 Volts @ 0.55 Ampers(5 Minutes later)I decided to test it with my HTC ONE M7 and it produced this result:Via the "Ampere" app 0.4 Ampers or 400 mAVia Multi-meters +5.08 Volts (sometimes jumps to +5.09 Volts)@ 0.44 Ampers

author: Rick Law
author_rank: Super Contributor
timestamp: February 19, 2017, 06:09:16 pm
content: Now you can use the app "Ampere" to see if your charger is working right. Good luck. Good thing to do is to run "Ampere" without charge plug in to get a feel for how much power your phone is using and how it changes over time. Then plug your charger in and see how it changes again. The power that charges the battery would be the power that your charger put out minus what your phone is using.Then tie D+ to D- to see how it goes. "Ampere" should report an increased power in if indeed your phone use that method of detection before it goes high-power.While "Ampere" can't give good accuracy, it does give you a feel as to how things are going.Kudos toBraintrapp- from what he said on his google-play store, he is an EEVBLOG forum member.As to your home made power bank... I would not be that courageous. There is so much power in 12x18650.It can start quite a fire if something goes wrong; and there are a lot of little things that can go wrong. I would not be comfortable to run that in my house. Look at this thread:https://www.eevblog.com/forum/beginners/diy-li-ion-from-toshiba-battery-pack/I think eBastler is right on with this reply in the thread linked above:Quote from: ebastler on February 19, 2017, 01:57:13 pm

author: Benxd10
author_rank: Newbie
timestamp: February 20, 2017, 06:42:52 pm
content: I think I may have solved my problem.When I shorted D+ and D- togeather on the USB side of my adapter while charging my phone, it yielded these results:+4.83 Volts @ 0.98 AmpsMy only concern is, does that V-droop indicates something could go wrong.Also, I see the concern about my battery bank. I figured those 18650s wouldn't heat up then explode by themselves because of such a low current draw between them, but in the case that some freak accident occurs such as the regulator being cheap and could be broken by an external power source that has a huge spike in power...FYI I got the batteries from "DELL"

author: Rick Law
author_rank: Super Contributor
timestamp: February 20, 2017, 07:44:09 pm
content: Quote from: Benxd10 on February 20, 2017, 06:42:52 pmYup! Actually almost 1A is not too bad. That is why I described my Kindle-2A charger voltage dip problem. The voltage was dropping below what the USB-charge-port needs to draw more current. I found most power-bricks will dip quite a bit. That is also the reason why I was seriously doubting that you can draw close to 1.5A.As long as your power-brick is holding out, it should do ok. BUT since it dips that much, I would not rule out that after a while, it could freak out.Who knows what it may do when it freaks out so surly there is no guarantee.Spend some time with it while it runs. Touch and see if anything is getting too hot to touch/hold. Run it for a couple of days to see if you are comfortable using it.This is a good time to have a dummy-load. I have a dummy load (home made, +-5%) that I can log to PC to make myself comfortable with the connection and the power source capability.re: "Also, I see the concern about my battery bank. I figured those 18650s wouldn't heat up then explode by themselves because of such a low current draw between them."Yeah, may be. Charging 12x18650 with 1A isnot going to get it too hot if things are going right- but what if something goes wrong?- (self-developed internal short due to battery way out of shape) If you look at the other thread I linked to, I described a playing around with my old (10+ year old) StarTac sub-1000mAH battery which all a sudden went hot by itself. Since I was playing with it, I do not rule out it was my dumb mistake instead of it being a purely self-developed short. Whatever it was, it went hot. Say if one of your battery starts to go, you have 11 other battery shorted by it. Poof! Fireworks!- (old battery too out of shape) I have some recovered 18650 that after charging to near 4.0V (not yet full, obviously), it stops charging and turns the incoming current into a heat. If I did not have a temperature monitoring charge process, I could be crispy to very-crispy later that evening.- How good/bad is the charger you are using? I am referring to the one that goes from your +5V input to the batteries. What if something goes wrong there and it tries to charge the batteries at 4.5V or even 4.8V? (ie: your charger voltage regulation died and just pass the 4.8V along directly to the batteries.)A boat load of little things can happen.If you use a good 18650 charger, charge them individually, and power-bank each battery as 12 separate 1x18650 power-banks, the damage is limited. When you have 12 in one pack, just one of them going south could make the whole pack go with it...Call me Chicken - I am probably too conservative. In my view, life is risky enough without adding unnecessary risks.

author: Benxd10
author_rank: Newbie
timestamp: February 21, 2017, 12:24:21 am
content: I have tested my D-link charger in this config for 4 hours:1 peltier+ 1 blower fan, which produces:+4.55 Volts @ 1.84 AmpsI'm not sure if I was supposed to test it with a similar load compared to my cell phone, but I figure a bigger load if my d-link adapter was going to fail, would put it in a worse cases situation or something like that.So far I have not seen any funny business from my adapter that I can see from my multimeters that is.So about my battery bank, I will disassemble it. If it was to explode I'd be in so much debt I wouldn't know what to do. Thanks for informing me.Edit: I forgot to mention that my D-link adapter durring this 4-hour test has only felt warm to the touch.

author: Rick Law
author_rank: Super Contributor
timestamp: February 21, 2017, 01:51:23 am
content: Quote from: Benxd10 on February 21, 2017, 12:24:21 amAs long as you feel comfortable. Looks likeyou have a "new" 1A charger for your phone.Since it is a 2.5A power source... If you want to try to charge at >1A, this trick may be work for you too:My Kindle-2A charger dips too much and wont charge at 1.1A (1.1A looks like it is my phones max), so this is just like your power brick situation of voltage dipping too much.One way I have learned to trickthe system is immediately after I plug in the phone, as quickly as I can, I turn off the screen (which reduces the current draw and that in-turn reduce the voltage dip). I have to do that very quickly, but if I catch it while the phone is still deciding, that screen-off reduction in voltage dip prevented my phone from lowering max current draw. I can charge it at 1.1A which is the same rate as my "better" ASUS 1.4A charger. Most of the time, I found it not worth the trouble. If it is so important to me to get it charged just a bit sooner, I just take the trouble to grab the ASUS 1.4A charger.As to your 12x18650 power bank. Sorry to have been a party pooper. That StarTac battery going hot really scared me. So hot I could not hold it and had to grab it with pliers to take it out door. It was a good thing. I learned to respect the power those LiIon batteries can deliver.