Mobile Device Power Monitor Battery Connection Quick Start Guide

Transcription

1 Mobile Device Power Monitor Battery Connection Quick Start Guide Distributed By: Monsoon Solutions, Inc. Introduction The Power Tool software and the Mobile Device Power Monitor hardware provide a robust power measurement solution for Windows Mobile powered devices. The Power Tool software and the Mobile Device Power Monitor hardware can analyze the power on any device that uses a single lithium (Li) battery. Electrical engineers and software developers can utilize the Power Tool software and the Mobile Device Power Monitor hardware to optimize the design and analyze the performance of their Windows Mobile powered devices. This guide will assist in setting up the device under test and its battery to start monitoring its current consumption. Hardware and Software Requirements for the Development Workstation A dedicated workstation is required to be used with the Mobile Device Power Monitor to achieve the optimal performance and results. Microsoft Windows XP SP2, Windows Vista or Windows 7 (32 or 64 bit) 1 GHz 32-bit (x86) or 64-bit (x64) processor 1 GB of system memory 40 GB hard drive with at least 15 GB of available space Full Speed USB 1.1/USB 2.0 integrated chipset or PCI/PCI Express add in card. USB Hubs should not be used with the Mobile Device Power Monitor

2 Connecting the Mobile Device Power Monitor Hardware 1. To connect the Mobile Device Power Monitor hardware be sure that the power switch on the front of the Mobile Device Power Monitor hardware is not engaged. The hardware should not be powered-up. The power switch should be in the outward position, not the inward position. 2. Connect the 6 volt power supply to the back of the unit. 3. Connect the B side of a 2.0 USB cable to the back of the Power Monitor and the A side of the USB 2.0 cable to the workstation. Figure 1. Back view: Power connector and USB connector.

3 4. Turn on the Mobile Device Power Monitor hardware by engaging the power button on the front. After turning on the Mobile Device Power Monitor hardware, the internal fan briefly powers-up and then powers-down. Initially, the power light-emitting diode (LED) is orange, and then it turns green. The green LED is connected directly to the internal power of the Mobile Device Power Monitor. Figure 2 below shows a view of the front of the Mobile Device Power Monitor hardware, where you can see the power button is engaged, and the green LED is powered-up. Figure 2. Front view: Engaged power button and powered-up green LED.

4 Connecting the Mobile Device Power Monitor Hardware It can take 30 minutes or longer to configure a good test connection. You will need a device that can measure voltage and resistance, such as a voltmeter/ohmmeter. Note Wear safety goggles at all times while working with exposed battery terminals and wiring. ************************************************************** Connecting the Mobile Device Power Monitor to a device to collect current measurements can be complicated and dangerous. Be sure that the area you are conducting power measurements is protected from fire dangers, do not have flammable items nearby. These measurements are at your own risk, and these procedures are not guaranteed to prevent damage or injury ************************************************************** Note There is no way to guarantee completely that the proper connection can be found. When attaching the power measurement hardware to a device with a lithium battery, there is always a risk of damaging the device, or causing the device to heat-up, generate smoke, or catch fire. While this is unlikely, be extremely careful, and if anything gets hot, immediately remove the battery and the power source. The following sequence of steps outlines how to connect the Mobile Device Power Monitor: 1. Creating Test Leads for the Mobile Device Power Monitor 2. Finding the Ground Pins on the Battery Connector 3. Finding the Battery Voltage Pins on the Battery Connector 4. Applying Copper Tape and Insulating Tape to the Lithium Battery 5. Testing the Copper Tape Connections. 6. Connecting the Battery to the Mobile Device Power Monitor

5 Creating Test Leads for the Mobile Device Power Monitor Figure 3. Example of a Correct Test lead Implementation

6 If the device under test is exhibiting low battery warnings and the use a higher voltage to power the device up is required, it is likely that the test leads are too long and at the incorrect cable gauge rating. Figure 4 below shows cables that might produce a bad connection. Figure 4

7 Finding the Ground Pins on the Battery Connector The battery connector could have one or more pins that are wired to ground (Zero volts) Often, there are multiple battery connector pins to lower the resistance and improve reliability. To find the ground pins on the battery connector: 1. Remove the battery. 2. Look at the device to see if the Positive (+) and Negative (-) terminals are labeled. If they are not, proceed to Step Use an ohmmeter to detect if there are multiple pins that are shorted together. If this is the case, then these pins are usually either the ground pins (GND), or the battery voltage pins (VBAT). 4. Measure the resistance between the various chassis points and the mating connector pins on the phone. The resistance to the ground pins should be less than 1 ohm. The chassis is usually grounded. For example the jacket on the USB connector is often grounded. Alternatively, inside the device, look for a metal shield soldered to the printed circuit board (PCB), or a shield trace on the PCB, these are usually DC grounded. Finding the Battery Voltage Pins on the Battery Connector It is not always trivial to identify the VBAT pins. Here are some common pitfalls. A pin on the battery connector is used as a thermal detector, which connects to a negative temperature coefficient resistor. These can be connected to GND or VBAT. A battery has a gas gauge (GG) on it. The GG communicates with the system over a one-wire bus with a pull-up resistor to VBAT or an intermediate voltage. The VBAT is disconnected from the pins by one of the battery's protection mechanisms, which makes finding VBAT non-trivial. Batteries may have antennas or other unrelated signals. To find the battery voltage pins on the battery connector. On the battery, use the GND pin to measure the voltage on the other pins of a fully charged battery. The voltage on VBAT should measure between 3.7 V to 4.2 V. If a 1 k resistor is attached between the suspected ground pin and the VBAT pin, the voltage should remain at 4.2 V. If the voltage does not remain at 4.2 V, then the pin is probably not the ground pin. If the voltage drops under this load more than 0.1 V, then these are not the battery voltage pins. Try another pin and do not go on to the next step.

8 Applying Copper Tape and Insulating Tape to the Lithium Battery Apply copper tape to the battery so the copper tape contacts with the GND pins on the battery connector. Allow enough length on the copper tape so you can connect the copper tape to the test leads from the Mobile Device Power Monitor. Be sure the sticky side of the copper tape for the GND pins is pressed firmly against the battery ground conductor. For better contact with the battery, very carefully solder the sticky side of the tape to the battery. IF soldering is the option selected, use just enough heat to connect the copper tape to the battery contact, but not too much heat that might damage or destroy the battery. Be very careful. Apply insulating tape over the battery's voltage terminal to isolate the voltage terminal from any ground connection. Apply copper tape over the battery terminal's insulating tape. Allow enough length on the copper tape so you can connect the copper tape to the test leads from the Mobile Device Power Monitor. Figure 5 below shows an example of how to apply copper tape to the ground pins and how to apply insulating tape over the battery's voltage terminal. Figure 5

9 This copper tape is used to complete the positive voltage connection from the Mobile Device Power Monitor to the device via the battery. Be sure that the positive voltage copper tape is insulated from the battery positive voltage pins. Place the battery back into the device. Figure 6 below shows how to apply the copper tape over the insulating tape and how to place the battery back into the device. This will insure that the the copper tape can be connected to the test leads from the Mobile Device Power Monitor. Figure 6 Application of copper tape over the insulating tape.

10 Testing the Copper Tape Connections 1. Test the copper tape connections by first placing the battery back into the device. Do not connect Mobile Device Power Monitor yet. 2. Try to power-up the device. The device should not power-up because the battery voltage has been bypassed with the copper and insulating tape. If the device powers-up, then go back and reassess the GND and VBAT pins and the application of the copper and insulating tape. 3. If the device does not power up, then the connections are correct and testing may begin. Connecting the Battery to the Mobile Device Power Monitor ******************************************************************* Use extreme caution when connecting the battery to the Mobile Device Power Monitor. A reversed battery connection or a short between the positive voltage and the GND could cause the battery to catch fire or explode. ******************************************************************* To connect the battery to the Mobile Device Power Monitor: Connect the battery to the main channel on the front of the Mobile Device Power Monitor by: a. Connecting the positive voltage copper tape to the red terminal post. b. Connecting the GND copper tape to the black terminal post. Select Vout Enabled in the Mobile Device Power Monitor UI and start testing.