How to know if your chargers are efficient

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

The phone has been charging for two hours, but it's all useless - some 30%. We are accustomed to blaming a prematurely dying battery, although it is often not the case at all. A guest post from Andrey Yakovlev will tell you how to find out if your charger is really fulfilling its purpose.

Recently, Lifehacker talked about how to find problems in charging your gadgets using a USB tester. We present to your attention another method for which you do not need any additional equipment.

Modern smartphones and telephones provide their own charging by controlling the charging voltage level, charging current, battery voltage and battery temperature. The phone knows all these data and can show its owner in the service mode. It is also called engineering, factory or test.

Attention! If you are not sure of your actions, please do not enter your phone into service mode. Rumor has it that someone somehow managed to ruin their device while doing this.

And for those who are confident and not afraid, we continue.

For the purity of the experiment, we transfer our phone to the "airplane" mode (so that its consumption from charging does not float, depending on the strength of the GSM signals, Wi-Fi and Bluetooth). We turn off the GPS-receiver, turn off the automatic adjustment of the screen brightness.

We transfer the phone to the service mode. For my Lenovo, this is the #### 1111 # combination dialed in the dialer; for a Samsung phone, the combination * # 0228 # is suitable. I think you can easily find this combination for your device on the Internet. By the way, I came across a combination like * 777 #, which many complained about: after completing this USSD request, the owners of smartphones received some wildly expensive set of unnecessary options from the mobile operator. Probably, it was a layout of a site with service codes, I don't know. In any case, the included "airplane" mode will protect you from this. Also, keep in mind that service codes for phones usually start with * # (yes, there must be a hash mark) and do not requirepressing the call button.

So, we entered the service mode. The structure of the service menu is unique for each device manufacturer. In my Lenovo, I selected Item Test → BatteryChargingActivity, some parameters just appeared in Samsung, and I scrolled down a couple of times until the desired values appeared.

To check the charges, we will monitor the amperage. It can be designated as Charging Current, is measured in mA (milliamperes) and has a value of "zero" when charging is not connected.

We collect the chargers we are interested in. It is better if there are more of them and they have detachable cables, then the quality of the analysis will be better.

I took several chargers with USB output and, accordingly, several USB → microUSB cables. Having connected them in various combinations to my device, for each combination I determined the minimum and maximum charging current (it floats a little in time) and wrote them down in the table.

Charge current in various combinations of charges and cables in milliamperes (minimum and maximum values)

	Cable 1	Cable 2	Cable 3
Charge 1	820…970	820…970	130…340
Charge 2	−150…0	−130…0	0
Charging 3.1	820…970	900…970	130…280
Charging 3.2	820…970	820…900	280…410
Charge 4	820…970	820…970	430…490
Charge 5	411…485	411…485	−73…+58

»

At the same time, we will calculate how many percent the current floats when charging. Let's write the results into the second table.

Change in current during charging in percent

	Cable 1	Cable 2	Cable 3
Charge 1	15	15	62
Charge 2	-	-	-
Charging 3.1	15	7	54
Charging 3.2	15	9	32
Charge 4	15	15	12
Charge 5	15	15	-

»

Based on the measurement results, the following conclusions can be drawn:

• The displayed current is not measured accurately, but with some step. Accordingly, do not pay close attention to the exact values of the measured current.
• My phone consumes about 1000 mA when charging (this can be seen on cables No. 1 and 2 in combination with chargers No. 1, 3 and 4 - the current values are similar to each other and the maximum of all measurements). This is evidenced by the maximum current written on the "native" charging - 1000 mA.
• Cables # 1 and # 2 transfer charging voltage equally well.
• Cable # 3 has a high resistance, so the charge current is much less than the intended one. It can be used for charging only in a hopeless situation. With the included GSM, Wi-Fi, Bluetooth modules, it is unlikely to be able to even maintain the battery level.
• Charge # 2 (declared as one amp) produces negative current, that is, flowing in the other direction. Instead of charging it, it discharges the gadget. By the way, the Samsung phone showed no negative current, but only zero.
• Charger No. 4 - from iPad, claimed to give 2,400 mA, has the highest power (this can be seen on "high impedance" cable No. 3). Charge No. 3 (declared as three-ampere) - dual, both connectors charge the phone equally well, but when a more powerful load (for example, a tablet) is connected to it, more current will be given through the second port. If we roughly estimate the ratio of the maximum currents on its connectors, obtained on a bad cable (280 and 410 mA), the first connector is capable of delivering 1200 mA, and the second - 1800 mA. This is indirectly confirmed by the maximum current drawdown (in the second table): the more powerful the charging, the less the drawdown.
• Charging No. 5 (car, cigarette lighter) gives insufficient current for charging (compared to charges No. 1, 3 and 4). Indeed, when traveling south with a smartphone in navigator mode for 16 hours of travel, she was only able to maintain the percentage of charge at one value.

To rehabilitate cable No. 3 a little, let's say that when it operates at a less demanding load, it interferes less: when charging a Samsung phone, instead of the required 453 mA, it transmits 354 mA, which can already be tolerated.

Here's what happened after the test of my exercises. Your results will be slightly different, but I think you got the general meaning: we find the maximum current from all combinations, determine the successful cables and chargers, and separately analyze the combinations that give lower current.

Good luck with your measurements!