[{"data":1,"prerenderedAt":337},["ShallowReactive",2],{"guide-en-jk-bms-reboots-power-events":3,"guides-en":277},{"id":4,"title":5,"body":6,"date":256,"description":257,"extension":258,"keywords":259,"meta":266,"navigation":267,"path":268,"related":269,"seo":273,"stem":274,"updated":275,"__hash__":276},"guides_en\u002Fguides\u002Fjk-bms-reboots-power-events.md","JK BMS Reboots and Charge MOS Off: Reading Power Events in the Log",{"type":7,"value":8,"toc":245},"minimark",[9,18,27,32,38,41,48,52,55,80,88,94,102,105,108,129,133,136,161,168,172,180,183,187,190,193,218,221,225],[10,11,12,13,17],"p",{},"If your JK BMS reboots, the Detail Log records it as a ",[14,15,16],"code",{},"Boot"," row. Most of those rows are harmless: you pressed the power button, or the app switched the BMS off and on. A few are not, and the log lets you tell them apart without guessing.",[10,19,20,21,26],{},"Here is how to tell expected restarts from unexpected ones and why a MOS can be off. For the file itself and how to export it, see ",[22,23,25],"a",{"href":24},"\u002Fguides\u002Fjk-bms-detail-log","how to export and read the JK-BMS Detail Log",".",[28,29,31],"h2",{"id":30},"what-a-boot-row-means","What a Boot row means",[10,33,34,35,37],{},"A ",[14,36,16],{}," row means the BMS started up. The first row after a start appears to be written before anything has been measured, so the cell voltages, pack voltage, current and temperatures are all zero. Only the capacity counters carry over, because they are stored. In the example log, a Boot row shows CHG OFF and DSG OFF, zeros everywhere, and remaining capacity 197.9 Ah out of 200.0 Ah.",[10,39,40],{},"Do not read those zeros as a deep discharge or a sensor fault. The numbers are simply missing. The next ordinary row has real values again.",[10,42,43,44,47],{},"When you connect the JK app after a restart, it sets the clock, and a ",[14,45,46],{},"Time calibration"," row follows. That row marks your own session. It is not a second problem.",[28,49,51],{"id":50},"expected-versus-unexpected-jk-bms-reboots","Expected versus unexpected JK BMS reboots",[10,53,54],{},"A Boot is expected when it comes a few seconds after a row that switched the BMS off. These rows qualify:",[56,57,58,65,70,75],"ul",{},[59,60,61,64],"li",{},[14,62,63],{},"Button to turn it off"," and the emergency button rows",[59,66,67],{},[14,68,69],{},"APP to turn it off",[59,71,72],{},[14,73,74],{},"Shutdown",[59,76,77],{},[14,78,79],{},"Enter sleep",[10,81,82,83,87],{},"The ",[22,84,86],{"href":85},"\u002Flogs","analysis page"," counts a Boot as expected when the row right before it is a power-off, button, emergency, shutdown or sleep row less than 60 seconds earlier. Any other Boot is counted as unexpected, except one on the very first row of the file, which has nothing before it to judge by.",[10,89,90,91,93],{},"The example log has 7 Boot rows and 2 unexpected ones. Five of them come 7 to 37 seconds after ",[14,92,63],{},", which is what a power-button restart looks like. The other two have no such row in front of them:",[56,95,96,99],{},[59,97,98],{},"A Boot at 23:53, about 20 minutes after a protection release and an app command to close charging. Nothing else sits near it.",[59,100,101],{},"A Boot at 00:21 on the next test day, about 70 seconds after the app closed charging and discharging. App switch commands do not count as a power-off, so this Boot is unexpected whatever the timing.",[10,103,104],{},"The log does not say why either restart happened, and neither does the analysis. Treat the count as a prompt to look.",[10,106,107],{},"Typical causes to check, in no particular order and none of them confirmed by the log alone:",[56,109,110,113,116,123],{},[59,111,112],{},"A supply dip. The BMS powers itself from the pack, so an almost empty pack or a heavy load spike could briefly drop its own supply.",[59,114,115],{},"A loose or corroded B- or power lead.",[59,117,118,119,122],{},"A firmware watchdog reset. This one is visible: the log contains a ",[14,120,121],{},"Reset Watch-Dog"," message, which the analysis files under faults.",[59,124,125,126,128],{},"The smart sleep setting, if the BMS goes to sleep and wakes again. Look for ",[14,127,79],{}," before the Boot.",[28,130,132],{"id":131},"why-charging-or-discharging-stopped","Why charging or discharging stopped",[10,134,135],{},"The CHG and DSG columns show whether each MOS was on in that row. A MOS that is off is not always a fault. Common reasons, from the rows around it:",[56,137,138,149,152,155,158],{},[59,139,140,141,144,145,148],{},"The app, RS485 or CAN switched it off. These appear as rows such as ",[14,142,143],{},"APP close charge"," or ",[14,146,147],{},"RS485 discharge off",". An inverter or charger that controls the BMS over RS485 or CAN can do this too.",[59,150,151],{},"A protection tripped. The trip row names the protection, and the release row is usually followed by the MOS turning on again. A long off period with no release row means the protection was still active.",[59,153,154],{},"A temperature protection or the heater state. Low-temperature charge protection keeps charging off until the pack warms up.",[59,156,157],{},"Power-off voltage or sleep: the BMS switched itself off.",[59,159,160],{},"A Boot row: both MOS show OFF in that row.",[10,162,163,164,26],{},"On the analysis page, the State lane draws CHG, DSG, balance and heater as bars on a timeline. Lining a gap in the CHG lane up with the event list underneath usually shows which of the cases above applies. For the meaning of each message, see ",[22,165,167],{"href":166},"\u002Fguides\u002Fjk-bms-log-messages-explained","JK BMS log messages explained",[28,169,171],{"id":170},"high-mos-temperature","High MOS temperature",[10,173,174,175,179],{},"The BMS has its own MOS over-temperature protection. When it trips, you get a MOS over-temperature row and the MOS switches off. See ",[22,176,178],{"href":177},"\u002Fguides\u002Fjk-bms-parameters-explained","JK BMS parameters explained"," for the related settings.",[10,181,182],{},"The analysis also raises a separate \"MOS gets hot\" warning when the MOS temperature reaches 70 °C and no MOS over-temperature trip is in the log. That is a hint that the MOS ran hot without protecting itself yet. It usually points at a long high-current session or poor cooling, and it can be a reason to look at the current limits.",[28,184,186],{"id":185},"what-to-do","What to do",[10,188,189],{},"For expected reboots, nothing. A power-button restart is the BMS doing what you asked.",[10,191,192],{},"For unexpected ones:",[194,195,196,199,202,205,212],"ol",{},[59,197,198],{},"Open the rows just before the Boot. Look at the current and the lowest cell voltage in the last row before it. A large current or a very low cell points at a supply dip or an overload.",[59,200,201],{},"Check the wiring on B- and the power input for loose or heated connections.",[59,203,204],{},"Compare the Boot time with your inverter or charger log, if it keeps one. A restart at the same moment as an inverter event often has the same cause.",[59,206,207,208,26],{},"Look at the smart sleep and power-off voltage settings in the ",[22,209,211],{"href":210},"\u002Fparameters","parameter reference",[59,213,214,215,217],{},"If a ",[14,216,121],{}," message is present, note the firmware version and treat it as a firmware question.",[10,219,220],{},"If an inverter turns the MOS off, check its BMS settings and how it handles the charge voltage requests, which come from the RCV and RFV values.",[28,222,224],{"id":223},"check-it-with-the-log","Check it with the log",[10,226,227,228,231,232,235,236,239,240,244],{},"Load your ",[14,229,230],{},"detaillogs"," file on the ",[22,233,234],{"href":85},"log analysis page",". The reboots tile shows the Boot count and how many were unexpected. Switch the family filter to power to see only Boot, shutdown and sleep rows, and open the State lane to see where each MOS was off. If a restart is not the only thing going on, ",[22,237,238],{"href":24},"the Detail Log guide"," explains the other message groups. You can also connect your BMS or open a settings file in the ",[22,241,243],{"href":242},"\u002F","editor"," to review the power-off and sleep values before you change them.",{"title":246,"searchDepth":247,"depth":247,"links":248},"",3,[249,251,252,253,254,255],{"id":30,"depth":250,"text":31},2,{"id":50,"depth":250,"text":51},{"id":131,"depth":250,"text":132},{"id":170,"depth":250,"text":171},{"id":185,"depth":250,"text":186},{"id":223,"depth":250,"text":224},"2026-10-02","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.","md",[260,261,262,263,264,265],"jk bms reboot","jk bms keeps restarting","jk bms charge mos off","jk bms discharge mos off","jk bms shutdown log","jk bms turned off by itself",{},true,"\u002Fguides\u002Fjk-bms-reboots-power-events",[270,271,272],"jk-bms-log-messages-explained","jk-bms-detail-log","jk-bms-parameters-explained",{"title":5,"description":257},"guides\u002Fjk-bms-reboots-power-events","2026-10-04","BxvBe3k1vdgYgXhS0xRFxN105EQ4aAxym7AF06oOTyM",[278,283,287,291,294,298,302,305,309,313,316,320,321,325,329,333],{"path":279,"title":280,"description":281,"date":275,"updated":282},"\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.",null,{"path":284,"title":285,"description":286,"date":256,"updated":275},"\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.",{"path":288,"title":289,"description":290,"date":256,"updated":282},"\u002Fguides\u002Fjk-bms-cell-overcharge-protection-tripping","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":24,"title":292,"description":293,"date":256,"updated":275},"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":295,"title":296,"description":297,"date":256,"updated":275},"\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":299,"title":300,"description":301,"date":256,"updated":275},"\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":166,"title":303,"description":304,"date":256,"updated":282},"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":306,"title":307,"description":308,"date":256,"updated":275},"\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":310,"title":311,"description":312,"date":256,"updated":275},"\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":177,"title":314,"description":315,"date":256,"updated":275},"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":317,"title":318,"description":319,"date":256,"updated":275},"\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":268,"title":5,"description":257,"date":256,"updated":275},{"path":322,"title":323,"description":324,"date":256,"updated":275},"\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":326,"title":327,"description":328,"date":256,"updated":275},"\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":330,"title":331,"description":332,"date":256,"updated":282},"\u002Fguides\u002Fjk-bms-weak-cell-log","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":334,"title":335,"description":336,"date":256,"updated":275},"\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.",1791151315884]