> ## Documentation Index > Fetch the complete documentation index at: https://learning.kent.co.in/llms.txt > Use this file to discover all available pages before exploring further. # Quiz — Battery and BMS: 10 Questions with Answers > 10 multiple-choice questions on battery and BMS: closed-loop comms, CAN protocol, crossover cable, storage SOC, dormant wakeup, and SOC freeze diagnosis. Ten questions from the [Battery & BMS](/battery/bms-comms-basics) group. Work through all ten before scrolling to the key. Suggested pass mark: **8 / 10**. Each miss points to a source page — re-read it, not the whole group. ## Questions **1.** In a closed-loop BMS setup, the inverter display shows: * A. A fixed default SOC of 50 % until fully charged * B. Live SOC from the BMS and the battery model name * C. Only voltage — closed-loop does not transmit SOC * D. SOC rounded to the nearest 10 % *** **2.** The communication protocol that carries BMS data between the Kent Lithium Battery and the inverter is: * A. RS485 (Modbus) * B. RS232 * C. CAN * D. Ethernet *** **3.** On the RJ45 BMS port of the Kent inverter, CAN-H is on pin \_\_\_ and CAN-L is on pin \_\_\_: * A. Pin 1 and pin 2 * B. Pin 3 and pin 6 * C. Pin 4 (CAN-H) and pin 5 (CAN-L) * D. Pin 7 and pin 8 *** **4.** The Kent Lithium Battery uses a mirrored RJ45 pinout. The correct communication cable between the pack and the inverter is therefore: * A. A straight-through RJ45 patch cable — same as a network cable * B. Any CAT5 cable under 3 m * C. A crossover cable — CAN pins 4 and 5 are reversed between pack and inverter * D. A USB-A to RJ45 adapter *** **5.** The recommended SOC range for storing a Kent Lithium Battery pack when the system will be idle for an extended period is: * A. 0–10 % — empty is the safest storage state * B. 30–60 % SOC * C. Always charge to 100 % before storage * D. Any SOC below 80 % is acceptable *** **6.** When the BMS communication link is lost, the inverter displays a frozen SOC value. This indicates: * A. A battery calibration problem — the BMS has lost its cell data * B. A communication problem — check the cable, pinout, and seating before touching any settings * C. The battery is at end of life * D. Normal behaviour when PV is not producing *** **7.** The Kent G3 Battery Healing switch is used to: * A. Charge the battery to 100 % from the grid without allowing discharge, restoring SOC accuracy * B. Balance cells by forcing a full discharge to empty * C. Replace faulty BMS firmware over the CAN link * D. Run an automatic monthly capacity test *** **8.** A dormant Kent Lithium Battery pack that has gone into deep-discharge protection should be woken using: * A. A bench power supply connected briefly to the pack terminals to inject a small charge * B. The official inverter function only — Kent G3 Battery Wakeup switch / Kent M1 Activate Bat * C. Shorting the battery terminals briefly to trigger the BMS reset * D. Holding the pack power button for 30 seconds *** **9.** The Kent F1-5120 battery pack maximum continuous discharge current is: * A. 100 A * B. 120 A * C. 60 A * D. 40 A *** **10.** In a multi-pack Kent Lithium Battery stack, the CAN communication cable runs from: * A. Every pack to the inverter, in a star topology * B. The master pack to the inverter — the master handles communication for the whole stack * C. The last pack in the string to the inverter * D. Pack to pack only — the inverter reads SOC via voltage *** ## Answer key | Q | Answer | Why | | -- | ------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 1 | **B** | Closed-loop BMS means live SOC and battery model name are shown on the inverter display. If the model name is missing or SOC is frozen, communication is broken. | | 2 | **C** | CAN is the lithium battery communication link on both Kent platforms. RS485 is used for meters and some older packs — not for the Kent Lithium Battery BMS. | | 3 | **C** | The inverter BMS RJ45 port has CAN-H on pin 4 and CAN-L on pin 5. The Kent battery pack mirrors this, which is why a crossover cable is needed. | | 4 | **C** | The Kent Lithium Battery pinout mirrors the inverter — CAN-H and CAN-L are on the same pin numbers at both ends. A crossover cable swaps them correctly. Use only the labelled Kent comm cable. | | 5 | **B** | Storage SOC is 30–60 %. Storing empty causes deep discharge; storing at 100 % accelerates calendar degradation. | | 6 | **B** | A frozen SOC is a communication symptom, not a calibration problem. Check the cable label, continuity, RJ45 seating, and pinout before changing any setting. | | 7 | **A** | Battery Healing on the Kent G3 charges the pack to 100 % from the grid without allowing any discharge, which re-anchors the BMS SOC calculation. | | 8 | **B** | Use only the inverter's official wakeup function. Jump-charging from a bench supply or shorting terminals can damage the BMS or the pack and voids the warranty. | | 9 | **C** | The F1-5120 maximum continuous discharge current is 60 A. System design must not demand more than this from a single pack. | | 10 | **B** | One CAN cable runs from the master pack to the inverter. The master manages communication for the whole stack — the inverter does not need individual connections to each pack. | ## Related pages * [BMS Comms Basics](/battery/bms-comms-basics) * [Cable Checks](/battery/cable-checks) * [Battery Safety](/battery/safety) * [SOC Mismatch](/battery/soc-mismatch)