[{"data":1,"prerenderedAt":526},["ShallowReactive",2],{"guide-en-jk-bms-not-charging":3,"guides-en":398},{"id":4,"title":5,"body":6,"date":375,"description":376,"extension":377,"keywords":378,"meta":385,"navigation":386,"path":387,"related":388,"seo":394,"stem":395,"updated":396,"__hash__":397},"guides_en\u002Fguides\u002Fjk-bms-not-charging.md","JK BMS Not Charging or Discharging: Why the MOSFET Is Off",{"type":7,"value":8,"toc":360},"minimark",[9,13,18,21,43,52,59,63,152,163,174,180,184,263,274,285,296,300,311,315,328,332,337,340,344,347,351,354],[10,11,12],"p",{},"A JK BMS that is not charging or not discharging has switched off its charge or discharge MOSFET, and it always has a reason. In most cases a cell reached a voltage limit, a temperature limit is active, an over-current protection is waiting out its recovery time, or the charge or discharge switch is simply off in the settings. Find which one it is first: look at the MOSFET state and the active alarm in the app or in a live monitor, then change only the setting that causes it.",[14,15,17],"h2",{"id":16},"read-the-state-before-you-change-anything","Read the state before you change anything",[10,19,20],{},"Every JK BMS reports three things you need:",[22,23,24,32,38],"ul",{},[25,26,27,31],"li",{},[28,29,30],"strong",{},"Charge MOSFET and discharge MOSFET:"," on or off.",[25,33,34,37],{},[28,35,36],{},"Active alarms:"," the protection that is tripped right now.",[25,39,40],{},[28,41,42],{},"The highest and lowest cell voltage, the temperatures and the current.",[10,44,45,46,51],{},"The JK app shows them on the main screen. In ",[47,48,50],"a",{"href":49},"\u002F","JK Preset Studio"," the live monitor shows the same values, keeps a chart, and turns a status chip amber or red when a protection trips, so you can see what happened just before charging stopped.",[10,53,54],{},[55,56],"img",{"alt":57,"src":58},"The JK Preset Studio live monitor: state of charge, pack voltage, current and cell spread on top, a cell strip and a live chart of the last minutes below","\u002Fscreenshots\u002Fmonitor.webp",[14,60,62],{"id":61},"why-a-jk-bms-is-not-charging","Why a JK BMS is not charging",[64,65,66,82],"table",{},[67,68,69],"thead",{},[70,71,72,76,79],"tr",{},[73,74,75],"th",{},"What you see",[73,77,78],{},"Likely cause",[73,80,81],{},"What to change",[83,84,85,97,108,119,130,141],"tbody",{},[70,86,87,91,94],{},[88,89,90],"td",{},"One cell at or above Cell OVP",[88,92,93],{},"Cell over-voltage protection",[88,95,96],{},"Charger voltage, balance, OVP and OVPR",[70,98,99,102,105],{},[88,100,101],{},"Pack voltage high, cells even",[88,103,104],{},"Charger voltage above the pack limit",[88,106,107],{},"Charger settings or Cell OVP",[70,109,110,113,116],{},[88,111,112],{},"Cold pack, alarm for low charge temperature",[88,114,115],{},"Charge under-temperature protection",[88,117,118],{},"Wait, heat, or check the limit",[70,120,121,124,127],{},[88,122,123],{},"Hot pack or MOS",[88,125,126],{},"Over-temperature protection",[88,128,129],{},"Cooling, current, temperature limits",[70,131,132,135,138],{},[88,133,134],{},"Alarm for charge over-current",[88,136,137],{},"Charge OCP, then recovery time",[88,139,140],{},"Charger current or the charge current limit",[70,142,143,146,149],{},[88,144,145],{},"No alarm, charge MOSFET off",[88,147,148],{},"Charge switch off in the settings",[88,150,151],{},"Turn the charge MOSFET switch on",[10,153,154,157,158,162],{},[28,155,156],{},"Cell over-voltage."," The most frequent case. One cell runs ahead, reaches Cell OVP and stops the whole pack while the others are still below full. The fix is rarely a higher OVP: it is a charger voltage that suits the cell count, a balancer that works earlier, and a recovery voltage (OVPR) far enough below OVP. The ",[47,159,161],{"href":160},"\u002Fguides\u002Fjk-bms-cell-overcharge-protection-tripping","overcharge protection guide"," walks through it.",[10,164,165,168,169,173],{},[28,166,167],{},"Temperature."," Lithium cells must not be charged below freezing, so the BMS blocks charging under the charge under-temperature limit. That is correct behaviour, not a fault. The ",[47,170,172],{"href":171},"\u002Fguides\u002Fjk-bms-temperature-heating-settings","temperature and heating guide"," explains the limits and the heater.",[10,175,176,179],{},[28,177,178],{},"Over-current."," If the charger pushes more than the charge OCP limit for longer than the delay, the BMS cuts off and waits for the recovery time, often 60 seconds, before it tries again. A large inverter charger can trip it again and again.",[14,181,183],{"id":182},"why-a-jk-bms-is-not-discharging","Why a JK BMS is not discharging",[64,185,186,196],{},[67,187,188],{},[70,189,190,192,194],{},[73,191,75],{},[73,193,78],{},[73,195,81],{},[83,197,198,209,220,231,241,252],{},[70,199,200,203,206],{},[88,201,202],{},"One cell at or below Cell UVP",[88,204,205],{},"Cell under-voltage protection",[88,207,208],{},"Charge the pack, check the weak cell",[70,210,211,214,217],{},[88,212,213],{},"Alarm for discharge over-current",[88,215,216],{},"Discharge OCP, then recovery time",[88,218,219],{},"Load, discharge limit, delay",[70,221,222,225,228],{},[88,223,224],{},"Output off right after connecting a load",[88,226,227],{},"Short circuit protection or inrush",[88,229,230],{},"Precharge, SCP delay, wiring",[70,232,233,236,238],{},[88,234,235],{},"Hot MOS or pack",[88,237,126],{},[88,239,240],{},"Cooling, current",[70,242,243,246,249],{},[88,244,245],{},"No alarm, discharge MOSFET off",[88,247,248],{},"Discharge switch off in the settings",[88,250,251],{},"Turn the discharge MOSFET switch on",[70,253,254,257,260],{},[88,255,256],{},"BMS dark, no Bluetooth",[88,258,259],{},"Sleep or power off voltage",[88,261,262],{},"Wake it or charge it",[10,264,265,268,269,273],{},[28,266,267],{},"Under-voltage."," When the lowest cell reaches Cell UVP, discharging stops until it recovers to UVPR. If one cell always gets there first while the rest are still well charged, that cell is weak. The ",[47,270,272],{"href":271},"\u002Fguides\u002Fjk-bms-weak-cell-log","weak cell guide"," shows how to spot it in the log.",[10,275,276,279,280,284],{},[28,277,278],{},"Over-current and short circuit."," A load above the discharge OCP limit trips after the delay and recovers after the recovery time. An inverter's capacitors can draw a huge current for a moment when you connect it, which looks like a short circuit. The ",[47,281,283],{"href":282},"\u002Fguides\u002Fjk-bms-ocp-scp-settings","OCP and SCP guide"," gives safe values.",[10,286,287,290,291,295],{},[28,288,289],{},"Sleep and power off."," A sleeping BMS turns everything off. The ",[47,292,294],{"href":293},"\u002Fguides\u002Fjk-bms-smart-sleep","smart sleep guide"," explains when that happens and how to wake it.",[14,297,299],{"id":298},"the-switches-nobody-checks","The switches nobody checks",[10,301,302,303,306,307,310],{},"The settings have a ",[28,304,305],{},"Charge MOSFET"," and a ",[28,308,309],{},"Discharge MOSFET"," switch. When one is off, the BMS blocks that direction completely and shows no alarm. They get turned off by accident in the app, by an imported settings file, or by an inverter that controls the BMS over RS485 or CAN. Read the settings and check both before you look for anything more complex.",[14,312,314],{"id":313},"find-the-cause-in-the-detail-log","Find the cause in the Detail Log",[10,316,317,318,322,323,327],{},"If the stop happened while you were not watching, export the Detail Log from the JK app and open it in the ",[47,319,321],{"href":320},"\u002Flogs","log analysis",". It pairs each trip with its release, shows the MOSFET state on a timeline, and names the setting behind each protection. The ",[47,324,326],{"href":325},"\u002Fguides\u002Fjk-bms-reboots-power-events","reboots and power events guide"," explains the CHG and DSG columns row by row.",[14,329,331],{"id":330},"faq","FAQ",[333,334,336],"h3",{"id":335},"why-does-my-jk-bms-charge-but-not-discharge","Why does my JK BMS charge but not discharge?",[10,338,339],{},"The discharge MOSFET is off. Check for an under-voltage, discharge over-current or temperature alarm, then check that the Discharge MOSFET switch is on in the settings. A remote command from an inverter can also switch it off.",[333,341,343],{"id":342},"how-long-does-a-jk-bms-stay-off-after-over-current","How long does a JK BMS stay off after over-current?",[10,345,346],{},"For the recovery time set for that protection, often 60 seconds for charge and discharge OCP. If the current is still too high when it switches back on, it trips again.",[333,348,350],{"id":349},"why-is-my-jk-bms-not-charging-when-the-cells-are-not-full","Why is my JK BMS not charging when the cells are not full?",[10,352,353],{},"One cell has probably reached Cell OVP before the others. Look at the highest cell, not the pack voltage. Balancing and a lower charger voltage fix it, not a higher OVP.",[10,355,356,359],{},[47,357,358],{"href":49},"Connect your BMS"," to read the MOSFET state, the alarms and every setting at once.",{"title":361,"searchDepth":362,"depth":362,"links":363},"",3,[364,366,367,368,369,370],{"id":16,"depth":365,"text":17},2,{"id":61,"depth":365,"text":62},{"id":182,"depth":365,"text":183},{"id":298,"depth":365,"text":299},{"id":313,"depth":365,"text":314},{"id":330,"depth":365,"text":331,"children":371},[372,373,374],{"id":335,"depth":362,"text":336},{"id":342,"depth":362,"text":343},{"id":349,"depth":362,"text":350},"2026-10-14","JK BMS not charging or not discharging? Find which protection or switch turned the MOSFET off, how to tell the causes apart and which setting fixes each one.","md",[379,380,381,382,383,384],"jk bms not charging","jk bms not discharging","jk bms not charging battery","jk bms charging stopped","jk bms no output","jk bms charge mosfet off",{},true,"\u002Fguides\u002Fjk-bms-not-charging",[389,390,391,392,393],"jk-bms-cell-overcharge-protection-tripping","jk-bms-ocp-scp-settings","jk-bms-temperature-heating-settings","jk-bms-weak-cell-log","jk-bms-reboots-power-events",{"title":5,"description":376},"guides\u002Fjk-bms-not-charging",null,"bGqf9L7x7gqVLffZv_mDJejoa5104B7VzebvHVvWQpw",[399,403,407,411,415,419,423,424,428,432,436,439,444,448,452,456,459,464,469,474,477,481,485,489,493,497,500,504,508,511,515,519,522],{"path":400,"title":401,"description":402,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-app-alternative","JK BMS App Alternative: Change Settings from Your PC or Browser","Looking for a JK BMS app alternative? Compare the JK app, the PC monitor software, ESPHome and a browser editor that reads and writes settings over Bluetooth.",{"path":404,"title":405,"description":406,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-bluetooth-not-connecting","JK BMS Not Connecting over Bluetooth: Fixes That Work","JK BMS not connecting or not pairing over Bluetooth? Work through the causes in order: sleep, another app holding the link, permissions, range and the browser.",{"path":408,"title":409,"description":410,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-calibration","JK BMS Voltage and Current Calibration: How to Do It Right","How to calibrate JK BMS voltage and current: what to measure, which value to enter, why calibration ends in Sending failure, and when to leave it alone.",{"path":412,"title":413,"description":414,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-error-codes","JK BMS Error Codes: What the Display and LEDs Are Telling You","JK BMS error codes explained: what the Err numbers, the ALM light and the app alarms mean, which codes users have matched to real faults, and how to find the cause.",{"path":416,"title":417,"description":418,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-firmware","JK BMS Firmware: V15 vs V19 and How to Update Safely","JK BMS firmware explained: how to read your hardware and software version, what changed from V11 to V15 and V19, and how to update without bricking the BMS.",{"path":420,"title":421,"description":422,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-first-setup","How to Set Up a New JK BMS: First Start Step by Step","Set up a new JK BMS the right way: wiring order, first power-on, passwords, cell count, a chemistry preset, current limits and a verified write over Bluetooth.",{"path":387,"title":5,"description":376,"date":375,"updated":396},{"path":425,"title":426,"description":427,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-not-turning-on","JK BMS Not Turning On: How to Start and Wake It Up","JK BMS not turning on? Learn how to activate a new board with a charger or the button, wake it from sleep, and find the wiring faults that keep it dark.",{"path":429,"title":430,"description":431,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-precharge","JK BMS Precharge: Stop Sparks and SCP Trips on Inverter Start","What JK BMS precharge does, why inverter capacitors trip short circuit protection, how to set the precharge time and when you still need a precharge resistor.",{"path":433,"title":434,"description":435,"date":375,"updated":396},"\u002Fguides\u002Fjk-bms-reset","How to Reset a JK BMS: SOC, Capacity, Alarms and Settings","How to reset a JK BMS: reset the SOC, the capacity, a stuck alarm or all settings, what the cycle count really is, and why you should back up before any reset.",{"path":293,"title":437,"description":438,"date":375,"updated":396},"JK BMS Smart Sleep: What the Voltage and Time Settings Do","What JK BMS smart sleep does, how the smart sleep voltage and time work together, how to wake a sleeping BMS and which values to use for home storage or a camper.",{"path":440,"title":441,"description":442,"date":443,"updated":396},"\u002Fguides\u002Fjk-bms-alarms-list","JK BMS Alarms List: Every Alarm, Its Cause and the Fix","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.","2026-10-12",{"path":445,"title":446,"description":447,"date":443,"updated":396},"\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":449,"title":450,"description":451,"date":443,"updated":396},"\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":453,"title":454,"description":455,"date":443,"updated":396},"\u002Fguides\u002Fjk-bms-parallel-batteries","JK BMS Parallel Batteries: Wiring, DIP Addresses and Settings","Connect several JK inverter BMS packs in parallel: busbar wiring, the RS485-2 link, DIP switch addresses, the master pack, matching settings and current limits.",{"path":171,"title":457,"description":458,"date":443,"updated":396},"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":460,"title":461,"description":462,"date":463,"updated":396},"\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":465,"title":466,"description":467,"date":468,"updated":396},"\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":470,"title":471,"description":472,"date":473,"updated":468},"\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":160,"title":475,"description":476,"date":473,"updated":396},"JK BMS Cell Over Charge Protection Keeps Tripping: Causes and Fix","JK BMS cell over charge protection tripping and releasing every minute? 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See factory defaults, how to change them, what to try if one fails, and what to do if lost.",{"path":325,"title":509,"description":510,"date":473,"updated":468},"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":512,"title":513,"description":514,"date":473,"updated":468},"\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":516,"title":517,"description":518,"date":473,"updated":463},"\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":271,"title":520,"description":521,"date":473,"updated":396},"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":523,"title":524,"description":525,"date":473,"updated":468},"\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.",1791980002503]