[{"data":1,"prerenderedAt":270},["ShallowReactive",2],{"guide-en-jk-bms-cell-overcharge-protection-tripping":3,"guides-en":212},{"id":4,"title":5,"body":6,"date":191,"description":192,"extension":193,"keywords":194,"meta":201,"navigation":202,"path":203,"related":204,"seo":208,"stem":209,"updated":210,"__hash__":211},"guides_en\u002Fguides\u002Fjk-bms-cell-overcharge-protection-tripping.md","JK BMS Cell Over Charge Protection Keeps Tripping: Causes and Fix",{"type":7,"value":8,"toc":181},"minimark",[9,13,18,21,24,27,31,34,37,53,56,60,63,89,92,96,99,133,136,139,143,146,178],[10,11,12],"p",{},"If the JK app shows \"Cell 01 over charge protection\" followed by \"Cell overcharge protection is released\" over and over, the JK BMS cell over charge protection is tripping in a loop. Charging stops, restarts, and stops again, sometimes several times an hour. Most of the time the cells are fine. The charger or inverter is asking for a voltage that sits above what the BMS allows per cell.",[14,15,17],"h2",{"id":16},"what-the-message-means","What the message means",[10,19,20],{},"\"Cell N over charge protection\" is a per-cell over-voltage trip. The BMS watches every cell, and when the highest one reaches Cell OVP it opens the charge MOS. No charge current can flow after that, whatever the charger does.",[10,22,23],{},"The BMS then waits and closes the charge MOS again, logging \"Cell overcharge protection is released\". In the example log this happens about 56 s later with the top cell back near 3.600 V, the OVP value, even though OVPR in the same BMS is 3.40 V. On this firmware the release seems to follow a timer or the OVP value, not OVPR. The number in the message is the cell that crossed the limit, counted from 1.",[10,25,26],{},"A single trip at the end of a full charge is normal. A trip that repeats every minute is not.",[14,28,30],{"id":29},"why-it-repeats-every-minute","Why it repeats every minute",[10,32,33],{},"The usual reason is a charger or inverter that holds the pack at a fixed voltage above cells × OVP. Charging pushes the top cell over the limit, the BMS cuts off, the cell drops back, the BMS releases after about a minute, and the charger pushes it over again.",[10,35,36],{},"The example Detail Log shows it clearly:",[38,39,40,44,47,50],"ul",{},[41,42,43],"li",{},"1090 over-voltage trips in four days, 1083 of them on cell 01.",[41,45,46],{},"Each trip comes at about 3.627 V with 22 to 23 A flowing.",[41,48,49],{},"The pack reads 29.0 V on 8 cells, which is 3.625 V per cell. The limit is 8 × 3.60 V = 28.8 V.",[41,51,52],{},"The release comes after about 56 s, and the next trip follows about 6 s later.",[10,54,55],{},"The charger holds roughly 29.0 V, so even a perfectly balanced pack ends up above the limit every time the BMS lets current through. With the cells this close together, the setpoint is the problem. The same config has Cell RCV at 3.45 V, which is 27.6 V for 8 cells, while the charger holds 29.0 V. That charger is not following the BMS request, which is why the fix starts at the charger.",[14,57,59],{"id":58},"setpoint-problem-or-weak-cell","Setpoint problem or weak cell",[10,61,62],{},"Look at the spread between the highest and lowest cell at the moment of the trip.",[38,64,65,72],{},[41,66,67,71],{},[68,69,70],"strong",{},"Spread under 20 mV."," The cells are in step and the whole pack is too high. Lower the charger voltage. The log analysis calls it a charger voltage problem when at least 80% of the trips happen with a spread under 20 mV.",[41,73,74,77,78,83,84,88],{},[68,75,76],{},"One cell far above the rest."," If at least 80% of the trips name the same cell and the spread is 50 mV or more, that cell is the outlier. Check the ",[79,80,82],"a",{"href":81},"\u002Fguides\u002Fjk-bms-balance-settings","balance settings",", the cell and its sense wire. The ",[79,85,87],{"href":86},"\u002Fguides\u002Fjk-bms-weak-cell-log","weak cell guide"," shows how to confirm it from the log.",[10,90,91],{},"The cell named in the message can mislead on its own. The spread is the better test.",[14,93,95],{"id":94},"how-to-stop-jk-bms-cell-over-charge-protection-tripping","How to stop JK BMS cell over charge protection tripping",[10,97,98],{},"Start at the charger or inverter, since that is where the voltage comes from.",[100,101,102,105,113,121],"ol",{},[41,103,104],{},"Set the absorption (bulk) voltage below cells × Cell OVP, with a margin. For 8 cells at 3.60 V OVP that means under 28.8 V. Many users leave 30 to 50 mV per cell of headroom, but check your cell datasheet.",[41,106,107,108,112],{},"Open the ",[79,109,111],{"href":110},"\u002F","editor"," and lower Cell RCV and SOC-100% voltage so the BMS requests less from a charger that follows its request voltage.",[41,114,115,116,120],{},"Keep the chain Cell OVP recovery \u003C SOC-100% voltage \u003C Cell RCV \u003C Cell OVP. The firmware rejects files that break it, see ",[79,117,119],{"href":118},"\u002Fguides\u002Fjk-bms-sending-failure","JK BMS sending failure",".",[41,122,123,124,128,129,120],{},"Compare the result with the ",[79,125,127],{"href":126},"\u002Fguides\u002Fjk-bms-lifepo4-settings","LiFePO4 settings guide",", or with the ready values on the ",[79,130,132],{"href":131},"\u002Fpresets","presets page",[10,134,135],{},"Balancing does not help here. The cells are already within a few millivolts, so there is nothing left to equalise. Raising Cell OVP only moves the limit closer to the cell's real maximum and is not a fix.",[10,137,138],{},"Changing the OVP to OVPR gap does not cure a charger that is set too high. The analysis page calls it cycling when there are 10 or more over-voltage trips and the median time from release to the next trip is under 60 s.",[14,140,142],{"id":141},"check-it-with-the-log","Check it with the log",[10,144,145],{},"You can confirm the diagnosis in a few minutes.",[100,147,148,156,168,171],{},[41,149,150,151,155],{},"Export the Detail Log from the JK app. The ",[79,152,154],{"href":153},"\u002Fguides\u002Fjk-bms-detail-log","Detail Log guide"," shows how.",[41,157,107,158,162,163,167],{},[79,159,161],{"href":160},"\u002Flogs","log analysis page"," and drop the ",[164,165,166],"code",{},".txt"," file in. It is read in your browser and never uploaded.",[41,169,170],{},"Read the finding \"Charger voltage above the OVP threshold\" and the episodes table. The table gives the cells, the peak cell voltage, how long the protection held and the re-arm time of each episode.",[41,172,173,174,177],{},"Attach the ",[164,175,176],{},".jkcfg"," of the same BMS. The charts then draw your Cell OVP, OVPR and RCV as lines, so you can see where the pack voltage sits against them. It also raises \"Trips do not match the config\" (median trip 3.629 V against OVP 3.600 V). That is expected when trips land above OVP.",[10,179,180],{},"After you change the charger and the file, export a new log a few days later. The trips should fall to a handful, usually at the end of a full charge.",{"title":182,"searchDepth":183,"depth":183,"links":184},"",3,[185,187,188,189,190],{"id":16,"depth":186,"text":17},2,{"id":29,"depth":186,"text":30},{"id":58,"depth":186,"text":59},{"id":94,"depth":186,"text":95},{"id":141,"depth":186,"text":142},"2026-10-02","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.","md",[195,196,197,198,199,200],"jk bms cell over charge protection","cell overcharge protection is released","jk bms ovp keeps tripping","jk bms overcharge protection","charger voltage above ovp","jk bms cell 01 over charge protection",{},true,"\u002Fguides\u002Fjk-bms-cell-overcharge-protection-tripping",[205,206,207],"jk-bms-detail-log","jk-bms-lifepo4-settings","jk-bms-weak-cell-log",{"title":5,"description":192},"guides\u002Fjk-bms-cell-overcharge-protection-tripping",null,"TAItlaNwKo4ZiQyGQuvPqUNYrZliCsy0Xex01qfwJUM",[213,218,221,222,225,229,232,236,240,244,248,252,256,259,263,266],{"path":214,"title":215,"description":216,"date":217,"updated":210},"\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":81,"title":219,"description":220,"date":191,"updated":217},"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.",{"path":203,"title":5,"description":192,"date":191,"updated":210},{"path":153,"title":223,"description":224,"date":191,"updated":217},"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":226,"title":227,"description":228,"date":191,"updated":217},"\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":126,"title":230,"description":231,"date":191,"updated":217},"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":233,"title":234,"description":235,"date":191,"updated":210},"\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":237,"title":238,"description":239,"date":191,"updated":217},"\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":241,"title":242,"description":243,"date":191,"updated":217},"\u002Fguides\u002Fjk-bms-ocp-scp-settings","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":245,"title":246,"description":247,"date":191,"updated":217},"\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":249,"title":250,"description":251,"date":191,"updated":217},"\u002Fguides\u002Fjk-bms-password","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":253,"title":254,"description":255,"date":191,"updated":217},"\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":118,"title":257,"description":258,"date":191,"updated":217},"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":260,"title":261,"description":262,"date":191,"updated":217},"\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":86,"title":264,"description":265,"date":191,"updated":210},"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":267,"title":268,"description":269,"date":191,"updated":217},"\u002Fguides\u002Fjk-bms-wire-resistance","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.",1791151315573]