SOLVED: iPhone 6 not showing any current, only show voltage — iPhone 6
Repair information and guides for the iPhone 6 that was released on September 19, 2014. Model Numbers: A1549, A1586, and A1589
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Azim WHITE
@azimwhite
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Hi I got an IPhone 6 sent in to me for repair regarding charging issue. This phone has no water damaged history. When charging the ammeter showing 0.01 — 0.02 (current), then I probe the battery connector while charging, my multimeter showing normal voltage (3.5v — 4.2v)
Okay let me straight forward, I’ve changed Charging Port, Battery, Tristar, Tigris and also i already checked the FL2511 it showing good sign. PP_5v0_USB also normal. PP_Tristar_Pin shows normal too
So what should I do next ?
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Minho
@refectio
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Hello Azim.
Is the phone booting properly with a know good battery or DCPS?
You’ve already done quite a few replacements under the assumption that this was a charging problem. However if the phone is not booting, a low current consumption can be caused by several issues. If the phone is only drawing 0.02A, then the boot sequence has failed almost immediately and it’s likely not a charging problem.
You’ll need to take a more analytical approach and test the primary voltage rails and then check what the PMIC is outputting (look for shorted lines) and then work your way toward I2C lines and RESET signals.
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jessabethany
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From your statement “Phone keeps rebooting” Does it reboot when booting with a known good charged battery? If so, then you have a gas gauge problem which points to battery or tigirs.
If it only reboots on DCPS, then that is because DCPS does not provide gas gauge and that is normal.
In a never been opened iPhone 6 that consumes no charging current but does boot, this is going to be tristar or tristar AND tigris. If you changed tristar and then tested, and the fault was actually bad tigris—-sometimes a bad tigris can kill a new tristar. Change them both again, but this time probe around tigris and make sure that you don’t have a short on any of its lines.
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reza.hassas
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I’ve also encountered this problem
When I turned on the device with a full battery, it indicated a 1% battery
I did the following steps, the problem was solved
1 — check for stuck battery pins.
Sometimes they wear out and stop working properly
2- check for corrosion in the line between bsi and tigris
But keep in mind that this method only works if the iphone keeps rebooting when plugged in without battery
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Battery: test for proper voltage? — iPhone 3GS
Revamped version of the iPhone 3G with faster processing speeds. Repair of this device is similar to the 3G, and requires simple screwdrivers and prying tools. Model A1303 / 8, 16 or 32 GB capacity / black or white plastic back.
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Chad Whitaker
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I have a iPhone 3GS that won’t power on, I have it all torn apart and have the battery out.
How can I test the battery with a multimeter to make sure it has a charge. Also I hear there is a way to use exposed wires on a usb wire to charge the battery?
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Joe Seraphim
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The outer two contacts are the main battery contacts — you should read about 3.
7 volts across them. The inner two contacts are for current monitoring (I think) as they only have small conductors.
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Mark
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A couple of points here from a design engineer of 30 years. On charge (and fully charged) a LiPo (Lithium Polymer) battery should have about 4.
20 — 4.30V across its terminals. With the charger freshly switched off the voltage will be about 4.1V. When fully discharged the battery voltage can be as low as 2.7V. Any lower than that and the battery is permanently dead! That’s why most LiPo batteries have overdischarge cutout built in.
As for Jonathan’s Amps, if you short out the iPhone battery (or connect your multimeter across it set to measure current) I would expect TENS of Amps to flow. This is a bad idea! Never connect a multimeter across a battery when set to measure Amps. The ability of a battery to supply current is not related to the capacity of the charger.
Measuring voltage is fine, but as Jonathan correctly points out it tells you nothing about the Amp-Hour capacity of the battery. To measure this you need to take a known current out of the battery and measure the time taken for the battery to reach end voltage (2.7-2-9V). Amp — Hours is exactly that, Amps(load) x Hours (Time).
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Jonathan
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Volts tested do not give indication of battery quality.
(confirmed) I bought a new battery off ebay and found I was experiencing the same low battery symptoms with my iphone that I had with the old battery. I tested the voltage of both batteries after a full charge and got 4volts *and 8.5 to 9 amps*. (*Correction I don’t know what I’m talking about in regards to amps. SOrry.*) After taking the phone to the technicians it turns out the batteries were no good. Next time I have my phone apart I’ll check the amps on the new battery. Any ideas how many amps a new battery should read?
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Replacement charge controller for Apple iPhone 5S. The iPhone is quickly discharged, when the battery is completely discharged, the iPhone does not charge from the charger.
Recently, a customer contacted us with an Apple iPhone 5S and complained about the rapid battery drain. The client told us that he had previously contacted another service center in Lipetsk and they replaced the battery with a new one, but the problem remained.
The iPhone was still quickly discharged, and once it was discharged to zero, it turned itself off, and no longer charged, did not turn on. Turning to this service under warranty, the «specialists» pushed the battery from the power supply and, lo and behold, the iPhone turned on again and started charging. But the percentage of iPhone charge was melting before our eyes. Since this «service center» could not solve the problem with the rapid discharge of the iPhone, the money was returned to the client.
It wasn’t the battery at all! If a client contacts us to replace the iPhone battery, we always carry out free diagnostics in order to identify a malfunction of the Tristar U2 charge controller. If the diagnostics shows a malfunction of this microcircuit, we change it and the iPhone starts charging properly again, and the battery holds its charge well! How we do this is described below.
Trying to charge the iPhone 5S from the power supply. We set the voltage to 5 volts (as in the charging unit) and insert the cord into the iPhone charging socket.
There is no current consumption, which means the battery is not charging at all!
Next, remove the display module, disconnect the battery and connect an external power source instead, setting the voltage to 4.2 Volts (as at the battery output) to the iPhone board and look, briefly press the power button and fix the increased current consumption (0.22A, instead of 0.06A).
This high current draw indicates a problem with the U2 Tristar power controller and should be replaced.
We unscrew the screws that secure the system board and remove it from the iPhone case. Using a board preheater or hot air gun, solder the protective screen from the board. The metal screen is soldered to a low-melting alloy, so a temperature of 200 degrees is enough to desolder it.
Unsolder the faulty U2 chip. You can solder the microcircuit using a hot air gun or a soldering iron with a special tip.
We take a new charge controller with knurled solder balls. Note that these balls are on lead-free solder, so the soldering temperature must be high and bottom heating of the board must be used.
We will not take risks once again and roll balls on lead-containing solder. We use 0.2 mm solder balls and a stencil with a suitable pitch and hole diameter.
Solder the chip.
We insert the system board into the iPhone case, put the cable of the charging socket on it and connect the charging cable to the socket. Now we see a current consumption of 0.88A, which means that the battery is charging! iPhone 5s repair
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Using an iPhone battery to develop wearable electronics / Sudo Null IT News
Greetings, reader.
Quite often I have the task of developing portable devices powered by a single Li-ion battery cell. And, if the customer usually does not care, then I, as an experienced engineer, shiver runs down my back at the sight of such a technical specification.
This is because estimating the battery charge level as well as the remaining operating time is a very difficult task, although at first glance it may seem otherwise.
There are several options in this case, we will talk about them below.
— The simplest thing is to do nothing to determine the battery charge level. Charging circuit on a simple linear charger (for example, on TP4054) and a voltage converter to power the device. It will turn off without warning and at the most inopportune moment.
— Measure battery voltage. The result is approximately the same as the previous paragraph, but requiring more effort. Typical scheme for measurement:
In fact, this is a voltage divider on resistors R19 and R21, connected through the VT6 key. Transistor VT7 is needed to eliminate the parasitic power supply of the MK through the EN pin.
VBAT — battery voltage
VBAT_mes — voltage coming to ADC
EN — divider control signal (0-off, 1-on)
Now we know the battery voltage, we are great fellows.
BUT it does almost nothing! The fact is that the typical Li-ion battery discharge curve, to put it mildly, is not linear and it depends on the current consumption and the temperature of the battery itself:0003
Looking at these graphs, what is the remaining battery capacity at 3.5V? I don’t think so…
This method can be slightly improved by using the thermal sensor built into the MCU to roughly estimate the temperature of the battery, and either put a sensor to measure the current, or (if the current consumption is approximately constant) plot a discharge curve for a typical current consumption. This will at least slightly justify the labor costs, but there can be no question of any accuracy. To indicate the charge on 3 LEDs — yes, it will.
In the case of constant current consumption, you can read the operating time from the battery and evaluate the consumed charge and the time spent on charge to estimate the accumulated charge. This method gives a cumulative error, since the calibration can only be at two points (full charge or full discharge), and they are not always achieved.
In addition, as the battery wears out, the maximum operating time should be adjusted, but in general, the method has the right to life.
— Make your own battery charge monitoring system (BMS). To implement it, we need current, temperature and battery voltage sensors. We believe that the MK is already in the device and it remains “only” to write software for it, which once took me a little less than a year.
— Take a ready-made Gas Gauge chip (for example, from TI or Maxim Integrated), configure it, calibrate it and run it. For example, the circuit for bq27220:
There are several nuances when choosing this concept:
- Gas Gauge, which allow the battery to be disconnected. In the first case, the battery of your device becomes unique and its replacement is possible only with your participation, which is not always convenient. In the second case, there is a problem of placing a temperature sensor on the battery.
- High cost solution.
Main components: Gas Gauge chip, protection chip, transistors, thermistor, current sensor resistor.
— Use simpler ready-made solutions like CW2015:
This is the Chinese equivalent of the MAX17048 chip. An absolutely simple microcircuit without temperature and current sensors, with a correspondingly low accuracy, but at the same time cheap, easy to use and program. It has the ability to work on the side of the device, which allows you not to modify the battery itself. The microcircuit was found in the vastness of the network in the process of writing the material, there is no experience with it, but there is a desire to try it, since the option is really interesting. Perhaps in the next article I will talk about this chip in more detail.
— And, finally, the last method known to me, to which I want to devote today’s article. In my opinion, this method is the simplest, but gives the best result. It consists in the fact that we take a battery from an iPhone with a built-in Gas Gauge and protection, connect via HDQ or I2C, poll and work.
In this case, the battery is already assembled and calibrated. Below is a table with battery options known to me:
The table is partially taken from the sites ripitapart.com and www.macplus.ru. Please pay special attention to the unknown controller marked A1141. This chip is manufactured by PowerFlash and that’s all the information we could find. The author of the blog from which I took the table was not sure that he got the original battery from the iPhone SE. Thanks to feedback asterix_tyumen , who dismantled the original battery from SE, it was found that it contains sn27545. Below we will be forced to consider A1141 in more detail. But for now, let’s look at the batteries:
As you can see, batteries for every taste and color, with and without an apple. They can also be connected in parallel to increase capacity, with separate polling. Among the shortcomings, it is worth noting that the length / width proportions are approximately 3: 1, which is not always convenient, as well as a unique connector for connecting.
Due to the popularity of Apple phones, these batteries can be easily bought in many places and in large quantities (as it turned out, this is not entirely true).
This is exactly the path we took when developing the wireless standalone RFID reader.
We chose a battery from the iPhone 6, which suited us both in terms of capacity and dimensions. Several copies were purchased in different places for testing:
The right one was bought in China, the rest in Moscow. Cost $6-11. When they are tested, quite interesting results will be obtained. Pay special attention to the box with the inscription «Orig», we will return to it later. Testing was done using the RFID reader itself, TI’s EV2300 programmer, and Battery Management Studio.
RFID reader power circuit is shown in the figure:
Linear memory based on STC4054 (TP4054), charge current 500 mA, power switch with auto-recovery based on reed switch SF1, capacitor C19, diode VD4 and resistor R15, as well as a pulse converter based on NCP1529.
The first I connected a copy from China for $6:
The battery responds, BUT the current was not displayed either when charging or discharging, the voltage did not correspond to the actually measured one and the degree of charge did not change. The battery did not respond to commands. There was an assumption that this copy is a fake, so I removed the protective tape from it to look at the board:
That’s a twist… I didn’t even redraw the circuit — here it’s clear that there is a bq27545 emulator and an overdischarge/overcharge protection circuit. Immediately the idea came to save yourself time and open all the batteries.
The neighbor to the left of the Chinese colleague for $ 8 is similar with a difference in the markings on the microcircuits. The rest behaves the same. These 2 copies go straight to the trash. Unfortunately, I did not have an iPhone 6 on hand to test these batteries in the target device, it was very interesting to see how the phone would behave when running on these batteries.
And this is the $8 central battery. It even has a current sensor and some kind of 8-pin microcircuit with a modest 6G3 marking. In Battery Management Studio, this battery pretends to be bq27545 more artfully. Displays the charge level, correct voltage, battery current. But if it were all real, then the fake wouldn’t be fake. In reality, the temperature was set to a constant, the current was measured very poorly. The picture shows the current consumption of the RFID reader, which is measured by the battery while constantly reading the card.
In reality, it is ~55 mA for this mode of operation, and since the reader field is always on, it cannot be zero. When charging (when the current is constant over a long period of time), the current sensor works normally. Naturally, all other parameters are calculated incorrectly (charge level, operating time until full discharge, etc.). The FC (Full charge) flag is set at 4.4V.
The battery does not respond to commands, the QEN and RUP_DIS flags are not set.
In general, this is an unsuccessful attempt by the Chinese to write a snag bq27545 on MK (in any case, I think it is). Also in the trash.
Remember, I asked you to pay special attention to the copy in the box with the inscription «Original»? It was he who turned out to be as close as possible to what we were looking for (and how can we not believe the advertisement now?):
Its cost was $9. In the center, the chip marked SN27545 is clearly visible — this is exactly what we were looking for. With this instance, I began to work more closely. During the test charge-discharge cycle, problems arose. I could not get the FC (Full charge) flag set, which meant the end of the charge process. The charge current at a battery voltage close to 4.2V became extremely small (about 20mA) and the charging process threatened to never end. One of the possible reasons turned out to be a USB cable with a large voltage drop (4.5V reached the memory chip), we replaced it with a better one with a lower voltage drop.
The indicators improved, the battery was charged to 4.2V, the current dropped to 0, but the SOC (State of charge) only reached 85, so the FC flag was not set.
For several days I cycled with the expectation that the battery would learn, but this did not help. The problem turned out to be commonplace, but it took 2 days to find it. At some point, I noticed that the battery was 4.35V and this was the answer to all questions. The memory is standard at 4.2V and I did not pay attention at all that the battery is 4.35V and an incomplete charge occurs. Since the boards were already manufactured, the only way out of the situation was to find a replacement STC4054 with a voltage of 4.35V. It turned out that such microcircuits exist, but in our great country you can’t easily buy them (apparently unpopular from the word at all). Therefore, the MCP73832T-3 variant was ordered with a wait of a couple of weeks.
In the meantime, the order is on its way, we will make a collective farm patch to test the concept.
To do this, we will make a “backup” of 0.15V for the memory chip using a diode:
,15V).
It is important to note that you can charge up to 4.2V with a corresponding loss of ~ 15% of capacity, but at the same time significantly extend the life of the battery. We have finished with the Orig copy — it can be safely put into development.
Last copy left. The most expensive ($11), in the coolest packaging and requiring the most time for myself. Let’s look at what’s inside:
Here it is an unknown chip A1141 for which there is no documentation other than the manufacturer’s page. With a forced connection as to bq27545 in Battery Management Studio, we see the following picture:
Complete garbage. When trying to charge with a current of ~ 500 mA, it shows 125 mA, when discharging with a current of ~ 25 mA, it shows 214 mA. It is clear that if A1141 has other parameter addresses or a data storage format different from bq27545, then nothing will shine with this battery without documentation.
Therefore, it was put aside, but at the end of writing the material, I decided to connect it again. I took the instruction table of the chip bq27545:
And read the voltage registers (0x08 and 0x09) through the Advanced Comm menu:
We get 0x10<<8 | 0x38 \u003d 4152 or 4.152V, which corresponds to the voltage measured by the multimeter 4.15V. So if the data is correct, why is 57mV displayed in the program ??? We notice that 57mV is exactly 0x38, that is, the value of the 0x08 register. With a battery voltage of 4.152V, the charge level of 96% looks quite correct, it can be obtained by reading registers 0x2c and 0x2d. Read 0x2c = 0x60, 0x2d = 0 (in the case of the SOC parameter, the high register is always zero). There was an assumption that the program or the EV2300 cannot read (or the battery does not respond) either the high byte in the request, or the byte with an odd address. To test this theory, the battery was connected directly to the RFID reader and the battery was polled through the MK.
The HDQ interface has been implemented according to a document from TI. The bq27545 microcircuit uses the single-wire HDQ protocol to communicate with the control controller, which is quite conveniently implemented on the STM32 based on a single-wire UART due to support for the Half Duplex mode.
our RFID reader is powered by MicroPython, we wrapped the HDQ work in a class and got the charge controller work like this:
from hdq import HDQ
bat = HDQ(pyb.UART(1))
bat.charge() # charge
bat.read_u16(0x14) # random register
It turned out that A1141 did not respond to a request to read bytes with odd addresses.
The oscillogram shows that there is a request, but no answer. When they added a reload of the data exchange logic (Break) before each request — every other time, but the microcircuit began to respond correctly.
Then we compared the exchange rate of EV2300 and RFID reader and it turned out that EV2300 uses a rate lower by 10-15% than set by TI:
After reducing the HDQ rate and performing Break on each request, the battery worked fine! The main parameters of the battery were read:
Complete victory! In fact, A1141 turned out to be a quality clone of bq27545 with minor flaws.