1.1. How to wake-up the smart battery (exit shipping mode)?
When a battery is delivered to the customer, it is in "shipping mode". In this mode, the battery outputs 0 V and does not shows any LEDs. To wake the battery (exit shipping mode), apply maximum charging voltage to the battery. Wait 10 seconds before establishing communication with the smart battery and make sure no other devices are communicating on the bus.
Keywords: no LED, no light, no voltage, no current, doesn't work, storage
1.2. Do I need to establish an SMBus communication between battery and charger?
We strongly recommend using a smart charger with SMBus communication.
The smart battery sends information about Charging Voltage and Charging Current. These parameters depend on battery type, temperature, and age of the battery. Without a smart charger, you risk charging the battery wrong, which may lead from increased aging to triggering its internal protective circuits.
1.3. Do I have to establish SMBus communication between battery and host?
RRC smart batteries can be used safely without establishing communication between the battery and the host.
However, it can be advantageous to exchange status information such as RelativeStateOfCharge(), RunTimeToEmpty() or BatteryStatus().
Setting Up Communication
2.1. What is the SMBus address of the smart battery?
As listed in the smart battery specification, the smart battery 7-bit address is 0b0001011.
2.2. What are the differences between I²C and SMBus?
I²C and SMBus look very much alike but are not the same. Some differences:
- Pull up resistors in the range of 10 to 15 kOhm for 3V3 systems and 15 kOhm for 5V systems.
- Clock speed 10 to 100 kHz
For more details, have a look at:
- General information: https://pdfserv.maximintegrated.com/en/an/AN476.pdf
- Physical layer specification: http://smbus.org/specs/smbus110.pdf
- Protocol layer specification: http://sbs-forum.org/specs/
Keywords: I2C, pullup, pull-up
2.3. How can I disable battery broadcasts?
You can switch off the ChargingCurrent() and ChargingVoltage() broadcasts by writing into register BatteryMode() (address 0x03) and setting flag “ChargerMode” (Bit 14) to 1.
Equally, you can switch off the AlarmWarning() broadcast by writing into register BatteryMode() (address 0x03) and setting flag "AlarmWarning" (Bit 13) to 1.
Please note that after the battery is reset (e. g., after waking up from shipping mode or a deep-discharged state), these flags are also reset, and the broadcasts begin anew.
Charging - Trouble Shooting
4.1. What is the procedure to charge a Li-ion battery?
The figure below shows that the charging process for Li-ion cells is split into two stages: the constant current phase (CC) and the constant voltage phase (CV). With a fully discharged battery, the CC phase is the first to take place. In this phase, the battery is charged by a constant current. Gradually, the voltage rises until it reaches the maximum charging voltage. Then the CV phase begins, in which the charging occurs at a fixed voltage. The charging current gradually decreases. When the charge current reaches a threshold called the "taper current", the battery is considered fully charged.
Li-ion Cell Charging Profile
4.2. How does a smart charger optimally charge a smart battery?
A smart charger either "listens" to the battery broadcasts of ChargingCurrent() and ChargingVoltage() parameters, or actively polls these registers. Both parameters are dynamically updated according to the JEITA profile, which optimizes the charging process of Li-ion batteries. The smart charger then applies the requested charging current and voltage to the battery terminals.
4.3. Do RRC batteries support JEITA profiles?
Yes. All RRC standard smart batteries support JEITA profiles. They serve to adapt ChargingCurrent() and ChargingVoltage() as a function of temperature and battery health.
4.4. What is the difference between SMBus charger level 2 and level 3?
A "Level 2" smart charger acts as an SMBus slave device only. It adjusts its output in direct response to ChargingVoltage() and ChargingCurrent () broadcasts sent by the smart battery. In Level 2 charging, the Smart Battery is completely responsible for initiating the communication and for providing the charging algorithm to the charger.
In contrast, a "Level 3" smart charger can act as an SMBus master device. Thus, the battery does not necessarily need to broadcast its charging parameters. The Level 3 Smart Battery Charger can also poll the Smart Battery to determine the charging voltage and current the battery desires, and then dynamically adjust its output to meet its charging requirements.
A Level 3 Smart Battery Charger is free to implement an alternative specialized charging algorithm. It may also interrogate the Smart Battery for any other relevant data, such as time remaining to full charge, battery temperature or other data used to control proper charging or discharge conditioning. For example, a medical device with stricter temperature limits than the Smart Battery's self-contained charging algorithm may use a Level 3 Smart Battery Charger that factors the battery's reported temperature into its charging algorithm.
4.5. What is PEC, and how can I use it correctly?
Packet Error Check (PEC) is an additional byte in the SMBus protocols used to check for an SMBus transmission error. Thus, it improves the communication reliability and robustness between the smart battery and the host/charger. If a charger level 2 is used paired with a battery that uses PEC in its broadcast, the charger must be PEC compliant.
The smart batteries which use PEC are: RRC2020; RRC2024; RRC2040; RRC 2040-2; RRC2054; RRC2057.
Discharging - Trouble Shooting
Coupling Multiple Smart Batteries
5.1. Do all smart batteries have the same SMBus Address?
As listed in the smart battery specification, the smart battery 7-bit address is 0b0001011. This is valid for all smart batteries. If you consider using more than one battery in your system, view question 5.2.
Keywords: communicate, communication, several, parallel, serial, series, two, 2
5.2. Is it possible to communicate with two or more batteries at once?
Since all smart batteries have the same SMBus address, it is necessary to use a 1-to-2 DEMUX (e.g., PCA9544A) to ensure independent communication with only one battery.
Keywords: communicate, several, parallel, serial, series
Smart Battery Qualification
6.1. How do I store smart batteries?
RRC batteries have a shelf life of 12 months under the following conditions:
- The battery is in shipping mode
- Ambient temperature is 25°C
- Initial SOC is 30% at 25°C.
To prevent the batteries from becoming deeply discharged, the user must recharge them to 30% SOC at least every 12 months. If the temperature is higher than 25°C, it may be necessary to recharge more often.
6.2. How much discharged capacity corresponds to one cycle count?
One cycle count corresponds to an accumulated discharge of 90% of design capacity.
6.3. What certificates and declarations have RRC’s smart batteries?
Please refer to the respective smart battery specification or the battery label to access the list of certificates that each smart battery has. This table shows the correspondence between the certificates and the countries in which they are valid.
Belarus /Kazakhstan / Kyrgyzstan
USA / Canada
Australia /New Zealand
6.4. How to obtain the smart battery certification documents, and how can they be acknowledged?
To access the certification documents, please ask your RRC sales representative. To acknowledge RRC smart batteries certificates in combination with your target application, you just need to present these documents to the certification authorities.
6.5. How will the new certifications for smart batteries affect RRC products?
RRC smart battery certificates are updated on a regular basis. Any new certificate introduced in the world market will be analysed. RRC is constantly paying close attention to this topic. In case there is any question regarding upcoming certificates, please contact your sales representative.
Keywords: obsolete, old
6.6. What concerns must be addressed when shipping Lithium-ion battery packs?
6.7. How does RRC ensure product quality?
RRC Power Solutions designs, develops and manufactures its products based on the quality management systems ISO9001, ISO14001 and ISO13485.
6.8. Does RRC have a Conflict Mineral Report?
6.9. Does RRC have a safety datasheet for the smart batteries?