[{"data":1,"prerenderedAt":595},["ShallowReactive",2],{"guide-en-jk-bms-alarms-list":3,"guides-en":517},{"id":4,"title":5,"body":6,"date":496,"description":497,"extension":498,"keywords":499,"meta":506,"navigation":507,"path":508,"related":509,"seo":513,"stem":514,"updated":515,"__hash__":516},"guides_en\u002Fguides\u002Fjk-bms-alarms-list.md","JK BMS Alarms List: Every Alarm, Its Cause and the Fix",{"type":7,"value":8,"toc":479},"minimark",[9,13,18,21,50,54,132,144,148,217,225,229,320,328,332,417,420,424,431,435,453,457,462,465,469,472,476],[10,11,12],"p",{},"A JK BMS reports its alarms as a set of flags in the live data it sends over Bluetooth. The app shows them as red text, and the Detail Log records the matching events. Some alarms are protections that switch a MOSFET off until a recovery condition is met. Others are faults in the hardware or the wiring that no setting will clear. This list covers every alarm the JK02 protocol reports, what it means and where to look.",[14,15,17],"h2",{"id":16},"how-to-read-an-alarm","How to read an alarm",[10,19,20],{},"Ask three questions for each alarm.",[22,23,24,32,38],"ol",{},[25,26,27,31],"li",{},[28,29,30],"strong",{},"Is it a protection or a fault?"," A protection (over-voltage, over-current, temperature) clears itself when the value returns past its recovery threshold. A fault (MOSFET, coprocessor, sensor) needs a check of the hardware.",[25,33,34,37],{},[28,35,36],{},"Which setting governs it?"," Every protection has a trip value, a recovery value or delay, and sometimes a related setting that makes it trip too early.",[25,39,40,43,44,49],{},[28,41,42],{},"How often does it happen?"," One trip on a cold morning is normal. The same trip every day is a setting or a cell problem. The Detail Log answers this, see ",[45,46,48],"a",{"href":47},"\u002Fguides\u002Fjk-bms-detail-log","reading the Detail Log",".",[14,51,53],{"id":52},"voltage-alarms","Voltage alarms",[55,56,57,73],"table",{},[58,59,60],"thead",{},[61,62,63,67,70],"tr",{},[64,65,66],"th",{},"Alarm",[64,68,69],{},"What it means",[64,71,72],{},"Settings that govern it",[74,75,76,88,99,110,121],"tbody",{},[61,77,78,82,85],{},[79,80,81],"td",{},"Cell overvoltage",[79,83,84],{},"A cell went above Cell OVP, charging stops",[79,86,87],{},"Cell OVP, OVPR, RCV, SOC-100% voltage, balance start",[61,89,90,93,96],{},[79,91,92],{},"Pack overvoltage",[79,94,95],{},"The whole pack is above its limit",[79,97,98],{},"Cell OVP and cell count",[61,100,101,104,107],{},[79,102,103],{},"Cell undervoltage",[79,105,106],{},"A cell went below Cell UVP, discharging stops",[79,108,109],{},"Cell UVP, UVPR, SOC-0% voltage, power off voltage",[61,111,112,115,118],{},[79,113,114],{},"Pack undervoltage",[79,116,117],{},"The pack voltage is below its limit",[79,119,120],{},"Cell UVP and cell count",[61,122,123,126,129],{},[79,124,125],{},"Battery fully charged",[79,127,128],{},"Information only: the charge reached the full condition",[79,130,131],{},"RCV and RCV time",[10,133,134,135,139,140,49],{},"Cell over-voltage that trips at the top of every charge usually means the charger voltage is above cells × OVP, or one cell runs ahead of the others. The ",[45,136,138],{"href":137},"\u002Fguides\u002Fjk-bms-cell-overcharge-protection-tripping","overcharge protection guide"," goes through both cases. Repeated undervoltage on one cell points to a weak cell, see the ",[45,141,143],{"href":142},"\u002Fguides\u002Fjk-bms-weak-cell-log","weak cell guide",[14,145,147],{"id":146},"current-alarms","Current alarms",[55,149,150,160],{},[58,151,152],{},[61,153,154,156,158],{},[64,155,66],{},[64,157,69],{},[64,159,72],{},[74,161,162,173,184,195,206],{},[61,163,164,167,170],{},[79,165,166],{},"Charge overcurrent",[79,168,169],{},"Charge current above the limit for longer than the delay",[79,171,172],{},"Max charge current, charge OCP delay and recovery",[61,174,175,178,181],{},[79,176,177],{},"Discharge overcurrent",[79,179,180],{},"Discharge current above the limit for longer than the delay",[79,182,183],{},"Max discharge current, discharge OCP delay and recovery",[61,185,186,189,192],{},[79,187,188],{},"Discharge overcurrent level 2 and 3",[79,190,191],{},"Faster, higher current stages of discharge protection",[79,193,194],{},"Hard-coded on most boards",[61,196,197,200,203],{},[79,198,199],{},"Charge or discharge short circuit",[79,201,202],{},"A current spike far above the rating",[79,204,205],{},"SCP delay and SCP recovery",[61,207,208,211,214],{},[79,209,210],{},"Short circuit release failed",[79,212,213],{},"The BMS could not recover after a short circuit",[79,215,216],{},"Check the load, then power cycle",[10,218,219,220,224],{},"Inverters that start a large motor or a capacitor bank can trip short circuit protection at switch-on. The ",[45,221,223],{"href":222},"\u002Fguides\u002Fjk-bms-ocp-scp-settings","OCP and SCP guide"," explains which values are safe to change.",[14,226,228],{"id":227},"temperature-alarms","Temperature alarms",[55,230,231,241],{},[58,232,233],{},[61,234,235,237,239],{},[64,236,66],{},[64,238,69],{},[64,240,72],{},[74,242,243,254,265,276,287,298,309],{},[61,244,245,248,251],{},[79,246,247],{},"Charge overtemperature",[79,249,250],{},"Battery too hot to charge",[79,252,253],{},"Charge OTP and OTPR",[61,255,256,259,262],{},[79,257,258],{},"Charge undertemperature",[79,260,261],{},"Battery too cold to charge",[79,263,264],{},"Charge UTP and UTPR, heating",[61,266,267,270,273],{},[79,268,269],{},"Discharge overtemperature",[79,271,272],{},"Battery too hot to discharge",[79,274,275],{},"Discharge OTP and OTPR",[61,277,278,281,284],{},[79,279,280],{},"Battery overtemperature",[79,282,283],{},"Battery temperature warning on newer boards",[79,285,286],{},"Discharge OTP",[61,288,289,292,295],{},[79,290,291],{},"Discharge undertemperature",[79,293,294],{},"Battery too cold to discharge (newer firmware)",[79,296,297],{},"Discharge UTP and UTPR",[61,299,300,303,306],{},[79,301,302],{},"MOSFET overtemperature",[79,304,305],{},"The BMS power stage is too hot",[79,307,308],{},"MOS OTP and OTPR",[61,310,311,314,317],{},[79,312,313],{},"Temperature sensor fault",[79,315,316],{},"A probe is missing, broken or shorted",[79,318,319],{},"Disable temperature sensors (troubleshooting only)",[10,321,322,323,327],{},"Charge undertemperature on the first cold night is the most common surprise. Many units leave the factory with Charge UTP at -20 °C, which is far too low for LFP. Set it to 2 to 5 °C, see the ",[45,324,326],{"href":325},"\u002Fguides\u002Fjk-bms-temperature-heating-settings","temperature and heating guide",". MOSFET overtemperature means the board is working too hard: too much current, poor airflow or a loose power connection.",[14,329,331],{"id":330},"hardware-and-wiring-faults","Hardware and wiring faults",[55,333,334,345],{},[58,335,336],{},[61,337,338,340,342],{},[64,339,66],{},[64,341,69],{},[64,343,344],{},"What to do",[74,346,347,362,373,384,395,406],{},[61,348,349,352,355],{},[79,350,351],{},"Balance wire resistance too high",[79,353,354],{},"A sense lead or its connector has high resistance",[79,356,357,358],{},"Check crimps and the wire resistance values, see the ",[45,359,361],{"href":360},"\u002Fguides\u002Fjk-bms-wire-resistance","wire resistance guide",[61,363,364,367,370],{},[79,365,366],{},"Cell count does not match the settings",[79,368,369],{},"Fewer or more cells detected than configured",[79,371,372],{},"Fix the Cell Count setting or a loose sense lead",[61,374,375,378,381],{},[79,376,377],{},"Charge or discharge MOSFET fault",[79,379,380],{},"The BMS could not switch a MOSFET",[79,382,383],{},"Contact the seller, the board may be damaged",[61,385,386,389,392],{},[79,387,388],{},"Discharge switch-on failed",[79,390,391],{},"The discharge MOSFET did not turn on, often into a large capacitive load",[79,393,394],{},"Use precharge, check the load",[61,396,397,400,403],{},[79,398,399],{},"Coprocessor communication error",[79,401,402],{},"The main chip lost contact with the measuring chip",[79,404,405],{},"Power cycle; if it returns, contact support",[61,407,408,411,414],{},[79,409,410],{},"Parallel module fault",[79,412,413],{},"The parallel current limiter (PCL) reported a fault",[79,415,416],{},"Check parallel wiring and the PCL setting",[10,418,419],{},"A cell count mismatch also hides other alarms, because the BMS cannot measure correctly. Fix it first.",[14,421,423],{"id":422},"remote-and-information-flags","Remote and information flags",[10,425,426,427,49],{},"The list also has flags that are not faults: GPS disconnected and Locked by GPS (for units with a GPS tracking module, used by rental and fleet owners), and Password change due, which some boards show while the default settings password is still in use. See the ",[45,428,430],{"href":429},"\u002Fguides\u002Fjk-bms-password","password guide",[14,432,434],{"id":433},"finding-the-pattern","Finding the pattern",[10,436,437,438,442,443,447,448,452],{},"A single alarm tells you what happened. A pattern tells you why. Export the Detail Log and drop it into the ",[45,439,441],{"href":440},"\u002Flogs","log analyser",". It pairs each trip with its release, shows the cell voltages and temperatures around it and links each finding to the setting that governs it. When you need to change a value, ",[45,444,446],{"href":445},"\u002F","connect your BMS"," in the browser, read the settings and fix the threshold with a backup in hand. The ",[45,449,451],{"href":450},"\u002Fparameters","parameters reference"," explains every field mentioned here.",[14,454,456],{"id":455},"faq","FAQ",[458,459,461],"h3",{"id":460},"can-i-clear-an-alarm-from-the-app","Can I clear an alarm from the app?",[10,463,464],{},"A protection clears when its recovery condition is met. A fault alarm stays until the cause is gone or the BMS restarts.",[458,466,468],{"id":467},"why-do-i-see-an-alarm-in-the-app-but-nothing-in-the-log","Why do I see an alarm in the app but nothing in the log?",[10,470,471],{},"The log records events, not every live flag. Short warnings such as wire resistance may only show live.",[458,473,475],{"id":474},"is-an-unknown-alarm-dangerous","Is an \"unknown alarm\" dangerous?",[10,477,478],{},"It means a flag without a published meaning. Note when it appears and export the log, then ask the seller.",{"title":480,"searchDepth":481,"depth":481,"links":482},"",3,[483,485,486,487,488,489,490,491],{"id":16,"depth":484,"text":17},2,{"id":52,"depth":484,"text":53},{"id":146,"depth":484,"text":147},{"id":227,"depth":484,"text":228},{"id":330,"depth":484,"text":331},{"id":422,"depth":484,"text":423},{"id":433,"depth":484,"text":434},{"id":455,"depth":484,"text":456,"children":492},[493,494,495],{"id":460,"depth":481,"text":461},{"id":467,"depth":481,"text":468},{"id":474,"depth":481,"text":475},"2026-10-12","All JK BMS alarms in one table: what each one means, what usually triggers it and which setting governs it, from cell OVP and MOS OTP to wire resistance.","md",[500,501,502,503,504,505],"jk bms alarms","jk bms alarm list","jk bms error codes","jk bms mos overtemperature","jk bms coprocessor communication error","jk bms temperature sensor fault",{},true,"\u002Fguides\u002Fjk-bms-alarms-list",[510,511,512],"jk-bms-log-messages-explained","jk-bms-parameters-explained","jk-bms-temperature-heating-settings",{"title":5,"description":497},"guides\u002Fjk-bms-alarms-list",null,"Kxq1OjtvauEfDklL0QA-lQUAZNyabGkiekQLgEGcYks",[518,519,523,527,530,535,540,545,548,551,555,559,563,567,570,574,577,581,585,589,592],{"path":508,"title":5,"description":497,"date":496,"updated":515},{"path":520,"title":521,"description":522,"date":496,"updated":515},"\u002Fguides\u002Fjk-bms-inverter-communication","JK Inverter BMS Communication: Deye, Victron and Growatt Setup","Connect a JK inverter BMS to Deye, Victron or Growatt over CAN or RS485: protocol number, port mode, DIP address, cable pinout and the inverter-side settings.",{"path":524,"title":525,"description":526,"date":496,"updated":515},"\u002Fguides\u002Fjk-bms-model-number-explained","JK BMS Model Numbers Explained: B2A8S20P, PB2A16S20P and More","Decode any JK BMS model name: series, balance current, cell count and current rating, plus the -H, -HC and -R suffixes and what they mean for heating, CAN and RS485.",{"path":325,"title":528,"description":529,"date":496,"updated":515},"JK BMS Temperature and Heating Settings: Safe Values for LiFePO4","Set JK BMS charge and discharge temperature limits, MOS OTP and the heating function. Why the -20 °C factory default is wrong for LiFePO4 and what to use instead.",{"path":531,"title":532,"description":533,"date":534,"updated":515},"\u002Fguides\u002Fjk-bms-soc-stuck-at-99","JK BMS SOC Stuck at 99%: Why It Never Reaches 100% and the Fix","JK BMS SOC stuck at 99% and never showing 100%? See what the BMS waits for at the end of charging, the six usual causes, and the settings that fix it.","2026-10-07",{"path":536,"title":537,"description":538,"date":539,"updated":515},"\u002Fguides\u002Fjk-bms-bluetooth-browser","Change JK BMS Settings over Bluetooth in Your Browser","Connect to a JK BMS from Chrome or Edge, read every setting, apply a preset and write it back in a safe order with read-back checks. No JK app needed.","2026-10-04",{"path":541,"title":542,"description":543,"date":544,"updated":539},"\u002Fguides\u002Fjk-bms-balance-settings","JK BMS Balance Settings: Start Voltage, Trigger, Current","JK BMS balance settings explained: start balance voltage, balance trigger voltage, max balance current and the Balancer switch, for LFP, NMC and LTO.","2026-10-02",{"path":137,"title":546,"description":547,"date":544,"updated":515},"JK BMS Cell Over Charge Protection Keeps Tripping: Causes and Fix","JK BMS cell over charge protection tripping and releasing every minute? See why a charger set too high causes it, how to tell it from a weak cell, and how to fix it.",{"path":47,"title":549,"description":550,"date":544,"updated":539},"How to export and read the JK-BMS Detail Log","What the JK-BMS Detail Log contains, how to export it from the app, how to read its events and what the log analysis page tells you about trips and faults.",{"path":552,"title":553,"description":554,"date":544,"updated":539},"\u002Fguides\u002Fjk-bms-export-import-settings","Export and Import JK BMS Settings: The .jkcfg File Guide","How to export and import JK BMS settings with the app, what the .jkcfg file contains, why hand edits break it, and how to edit it safely in your browser.",{"path":556,"title":557,"description":558,"date":544,"updated":539},"\u002Fguides\u002Fjk-bms-lifepo4-settings","JK BMS Settings for LiFePO4: 8S and 16S, 280Ah and 314Ah","JK BMS settings for LiFePO4 packs: per-cell voltage, balance, current and temperature values for 8S and 16S with 280Ah and 314Ah cells, in three wear levels.",{"path":560,"title":561,"description":562,"date":544,"updated":515},"\u002Fguides\u002Fjk-bms-log-messages-explained","JK BMS Log Messages Explained: Boot, Time calibration, Protections","What each JK BMS log message means: Boot, Time calibration, APP open charge, protection trips and releases, Discharge On Failed and Unknown Log Code [0].",{"path":564,"title":565,"description":566,"date":544,"updated":539},"\u002Fguides\u002Fjk-bms-nmc-lto-settings","JK BMS Settings for NMC and LTO: Safe Per-Cell Values","JK BMS settings for NMC and LTO packs: per-cell OVP, UVP, balance, temperature and C-rate values in three wear levels, plus how the editor detects chemistry.",{"path":222,"title":568,"description":569,"date":544,"updated":539},"JK BMS Overcurrent Protection Settings: OCP and SCP Guide","JK BMS overcurrent protection settings explained: charge and discharge OCP limits, delays, recovery times and SCP, with ranges and sizing for inverters.",{"path":571,"title":572,"description":573,"date":544,"updated":539},"\u002Fguides\u002Fjk-bms-parameters-explained","JK BMS Parameters Explained: Every Setting by Group","JK BMS parameters explained in one glossary: cell OVP, OVPR, UVP, UVPR, balance, SOC, RCV and RFV, current and temperature limits, with typical LFP ranges.",{"path":429,"title":575,"description":576,"date":544,"updated":539},"JK BMS Password: Default Codes, Change and Reset Guide","Your JK BMS password is really two codes: Bluetooth and settings. See factory defaults, how to change them, what to try if one fails, and what to do if lost.",{"path":578,"title":579,"description":580,"date":544,"updated":539},"\u002Fguides\u002Fjk-bms-reboots-power-events","JK BMS Reboots and Charge MOS Off: Reading Power Events in the Log","JK BMS reboots or the charge MOS switched off by itself? Learn to read Boot rows and MOS state in the Detail Log and tell expected restarts from real faults.",{"path":582,"title":583,"description":584,"date":544,"updated":539},"\u002Fguides\u002Fjk-bms-sending-failure","JK BMS Sending failure: Causes and Step-by-Step Fix","JK BMS Sending failure on import? See why the firmware rejects settings (voltage chains, write order, SCP delay) and how to fix it step by step.",{"path":586,"title":587,"description":588,"date":544,"updated":534},"\u002Fguides\u002Fjk-bms-soc-calibration","JK BMS SOC Calibration: Fix SOC Drift, Jumps and Reset","JK BMS SOC calibration explained: why SOC drifts or jumps, what the SOC-100% voltage and SOC-0% voltage do, and how to set them and recalibrate the pack.",{"path":142,"title":590,"description":591,"date":544,"updated":515},"Find a Weak Cell with the JK BMS Log: Trips, Spread and Balance","Find a weak cell in the JK BMS Detail Log: which cell trips first, how wide the spread is at the trip, and whether it is balance drift or a bad cell.",{"path":360,"title":593,"description":594,"date":544,"updated":539},"JK BMS Wire Resistance: Fix Abnormal Balance Wire Alarm","JK BMS wire resistance explained: what the abnormal resistance of the balance wire warning means, normal values, common causes and how to fix a bad lead.",1791798183925]