[{"data":1,"prerenderedAt":442},["ShallowReactive",2],{"guide-en-jk-bms-firmware":3,"guides-en":311},{"id":4,"title":5,"body":6,"date":289,"description":290,"extension":291,"keywords":292,"meta":299,"navigation":300,"path":301,"related":302,"seo":307,"stem":308,"updated":309,"__hash__":310},"guides_en\u002Fguides\u002Fjk-bms-firmware.md","JK BMS Firmware: V15 vs V19 and How to Update Safely",{"type":7,"value":8,"toc":274},"minimark",[9,13,18,21,38,47,51,54,130,133,164,172,176,179,222,225,229,232,235,239,242,246,251,254,258,261,265,268],[10,11,12],"p",{},"JK BMS firmware is tied to the hardware generation: a V15 board runs V15 firmware and a V19 board runs V19 firmware, and you cannot turn one into the other with an update. You update firmware with the JK PC software over a wired connection, not over Bluetooth. Back up your settings first, use only a file made for your exact hardware, and update only when you need a fix or a feature, because a failed update can leave the board unusable.",[14,15,17],"h2",{"id":16},"how-to-read-your-hardware-and-software-version","How to read your hardware and software version",[10,19,20],{},"Every JK board reports two versions:",[22,23,24,32],"ul",{},[25,26,27,31],"li",{},[28,29,30],"strong",{},"Hardware version",", such as 19H or 15A. The number is the generation; the letter is the board variant.",[25,33,34,37],{},[28,35,36],{},"Software version",", such as 19.25 or 19.26. The first part matches the hardware generation, the second part is the firmware release.",[10,39,40,41,46],{},"The JK app shows both in the device info. ",[42,43,45],"a",{"href":44},"\u002F","JK Preset Studio"," shows them too, right after you connect over Bluetooth, together with the model, the serial number and the uptime. Write them down before you look for firmware.",[14,48,50],{"id":49},"v11-v15-and-v19-what-changed","V11, V15 and V19: what changed",[10,52,53],{},"JK's own comparison of V11 and V15 lists the upgrades of V15:",[55,56,57,73],"table",{},[58,59,60],"thead",{},[61,62,63,67,70],"tr",{},[64,65,66],"th",{},"Feature",[64,68,69],{},"V11",[64,71,72],{},"V15",[74,75,76,88,99,110,121],"tbody",{},[61,77,78,82,85],{},[79,80,81],"td",{},"Temperature sensors",[79,83,84],{},"2",[79,86,87],{},"4",[61,89,90,93,96],{},[79,91,92],{},"Heating",[79,94,95],{},"on some boards",[79,97,98],{},"on all boards",[61,100,101,104,107],{},[79,102,103],{},"CAN and RS485",[79,105,106],{},"one or the other",[79,108,109],{},"both at the same time",[61,111,112,115,118],{},[79,113,114],{},"Alarm functions",[79,116,117],{},"no",[79,119,120],{},"yes",[61,122,123,126,128],{},[79,124,125],{},"Parallel operation",[79,127,117],{},[79,129,120],{},[10,131,132],{},"For V15 against V19 there is no official table. What owners report, and what we saw ourselves:",[22,134,135,141,147,158],{},[25,136,137,140],{},[28,138,139],{},"Ports."," On PB boards, V19 has a working RS232 port on the communication board; on V15 that port is reported as not connected. V19 also adds a separate UART port next to the display connector.",[25,142,143,146],{},[28,144,145],{},"Heating logic."," Owners report that heating behaves differently before and after firmware 19.05.",[25,148,149,152,153,157],{},[28,150,151],{},"Settings values."," Some settings are stored differently. On a JK-PB2A16S20P with software 19.26 the short circuit delay is stored as 5, and a settings file from an older board with 1500 is refused. The ",[42,154,156],{"href":155},"\u002Fguides\u002Fjk-bms-ocp-scp-settings","OCP and SCP guide"," has the details.",[25,159,160,163],{},[28,161,162],{},"Missing settings."," Even within V19, boards differ: a JK-B2A8S20P with hardware 19H refuses float voltage, heating and precharge time because it lacks those functions.",[10,165,166,167,171],{},"The practical result: a settings file from a V15 board often fails on a V19 board with a Sending failure. Write settings one by one instead of importing a file across generations, as the ",[42,168,170],{"href":169},"\u002Fguides\u002Fjk-bms-sending-failure","Sending failure guide"," explains.",[14,173,175],{"id":174},"how-to-update-jk-bms-firmware","How to update JK BMS firmware",[10,177,178],{},"The official procedure for PB inverter boards uses the PC software:",[180,181,182,198,204,210,216],"ol",{},[25,183,184,187,188,192,193,197],{},[28,185,186],{},"Back up your settings."," Read the BMS and save a ",[189,190,191],"code",{},".jkcfg"," file, as the ",[42,194,196],{"href":195},"\u002Fguides\u002Fjk-bms-export-import-settings","export and import guide"," shows. Firmware updates can reset settings.",[25,199,200,203],{},[28,201,202],{},"Connect by cable."," Use the USB to RJ45 cable from JK (RS485 or RS232, depending on the board) and select the right port in the PC software.",[25,205,206,209],{},[28,207,208],{},"Make the BMS a slave."," JK requires the device address to be other than 0 during the update, and the BMS must not talk to another master. Set the DIP switch and disconnect parallel links.",[25,211,212,215],{},[28,213,214],{},"Upgrade."," In the PC software open the menu at the top right, choose Upgrade Firmware, select the file and press Start Upgrade. The update is complete when the progress bar ends.",[25,217,218,221],{},[28,219,220],{},"Check and restore."," Confirm the new software version, then compare your settings with the backup and write back what changed.",[10,223,224],{},"Standard boards such as the B2A series are updated with the JK BMS Monitor PC software through an RS485 to USB adapter. Ask your seller which adapter fits your board before you buy one.",[14,226,228],{"id":227},"forced-upgrade-and-recovery","Forced upgrade and recovery",[10,230,231],{},"If the normal upgrade refuses a file, JK has a Forced Upgrade option. It needs an authorization code from the manufacturer, which exists to stop you from flashing a file meant for other hardware. If an update fails, JK's steps are: repeat the forced upgrade; keep the activation or display switch pressed; press and release the RST button; wait for the progress bar to finish.",[10,233,234],{},"Be careful with firmware files from cloud links and forums. There is no public, signed release channel, and at least one file shared as a new version turned out to be a test build without working firmware.",[14,236,238],{"id":237},"should-you-update-at-all","Should you update at all?",[10,240,241],{},"Update when a specific fix or feature matters to you: a bug in inverter communication, a heating change, a setting your firmware lacks. If the BMS works and protects your cells, the risk of a failed update usually outweighs the benefit.",[14,243,245],{"id":244},"faq","FAQ",[247,248,250],"h3",{"id":249},"can-i-update-a-jk-bms-over-bluetooth","Can I update a JK BMS over Bluetooth?",[10,252,253],{},"No. Firmware updates use the JK PC software over a cable. The phone app and Bluetooth tools read and write settings only.",[247,255,257],{"id":256},"can-i-turn-a-v15-bms-into-a-v19-bms-with-firmware","Can I turn a V15 BMS into a V19 BMS with firmware?",[10,259,260],{},"No. The version follows the hardware generation. V19 firmware is not meant for V15 boards, and flashing the wrong file can brick the board.",[247,262,264],{"id":263},"will-a-firmware-update-erase-my-settings","Will a firmware update erase my settings?",[10,266,267],{},"It can. Save a backup file before updating and compare the settings afterwards.",[10,269,270,273],{},[42,271,272],{"href":44},"Connect your BMS"," to see its hardware and software version and save a backup before you update.",{"title":275,"searchDepth":276,"depth":276,"links":277},"",3,[278,280,281,282,283,284],{"id":16,"depth":279,"text":17},2,{"id":49,"depth":279,"text":50},{"id":174,"depth":279,"text":175},{"id":227,"depth":279,"text":228},{"id":237,"depth":279,"text":238},{"id":244,"depth":279,"text":245,"children":285},[286,287,288],{"id":249,"depth":276,"text":250},{"id":256,"depth":276,"text":257},{"id":263,"depth":276,"text":264},"2026-10-14","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.","md",[293,294,295,296,297,298],"jk bms firmware","jk bms firmware update","jk bms v15 vs v19","jk bms firmware v19","jk bms firmware upgrade","jk bms forced upgrade",{},true,"\u002Fguides\u002Fjk-bms-firmware",[303,304,305,306],"jk-bms-model-number-explained","jk-bms-export-import-settings","jk-bms-sending-failure","jk-bms-ocp-scp-settings",{"title":5,"description":290},"guides\u002Fjk-bms-firmware",null,"fBwNmyrl0_cYooV7mRtkvntlpX2qHYlqBHvs6SCDjbk",[312,316,320,324,328,329,333,337,341,345,349,353,358,362,366,370,374,379,384,389,393,397,400,404,408,412,415,419,423,427,430,434,438],{"path":313,"title":314,"description":315,"date":289,"updated":309},"\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":317,"title":318,"description":319,"date":289,"updated":309},"\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":321,"title":322,"description":323,"date":289,"updated":309},"\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":325,"title":326,"description":327,"date":289,"updated":309},"\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":301,"title":5,"description":290,"date":289,"updated":309},{"path":330,"title":331,"description":332,"date":289,"updated":309},"\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":334,"title":335,"description":336,"date":289,"updated":309},"\u002Fguides\u002Fjk-bms-not-charging","JK BMS Not Charging or Discharging: Why the MOSFET Is Off","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.",{"path":338,"title":339,"description":340,"date":289,"updated":309},"\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":342,"title":343,"description":344,"date":289,"updated":309},"\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":346,"title":347,"description":348,"date":289,"updated":309},"\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":350,"title":351,"description":352,"date":289,"updated":309},"\u002Fguides\u002Fjk-bms-smart-sleep","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":354,"title":355,"description":356,"date":357,"updated":309},"\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":359,"title":360,"description":361,"date":357,"updated":309},"\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":363,"title":364,"description":365,"date":357,"updated":309},"\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":367,"title":368,"description":369,"date":357,"updated":309},"\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":371,"title":372,"description":373,"date":357,"updated":309},"\u002Fguides\u002Fjk-bms-temperature-heating-settings","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":375,"title":376,"description":377,"date":378,"updated":309},"\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":380,"title":381,"description":382,"date":383,"updated":309},"\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":385,"title":386,"description":387,"date":388,"updated":383},"\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":390,"title":391,"description":392,"date":388,"updated":309},"\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":394,"title":395,"description":396,"date":388,"updated":383},"\u002Fguides\u002Fjk-bms-detail-log","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":195,"title":398,"description":399,"date":388,"updated":383},"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":401,"title":402,"description":403,"date":388,"updated":383},"\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":405,"title":406,"description":407,"date":388,"updated":309},"\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":409,"title":410,"description":411,"date":388,"updated":383},"\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":155,"title":413,"description":414,"date":388,"updated":383},"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":416,"title":417,"description":418,"date":388,"updated":383},"\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":420,"title":421,"description":422,"date":388,"updated":383},"\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":424,"title":425,"description":426,"date":388,"updated":383},"\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":169,"title":428,"description":429,"date":388,"updated":383},"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":431,"title":432,"description":433,"date":388,"updated":378},"\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":435,"title":436,"description":437,"date":388,"updated":309},"\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":439,"title":440,"description":441,"date":388,"updated":383},"\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.",1791980002099]