[{"data":1,"prerenderedAt":381},["ShallowReactive",2],{"guide-en-jk-bms-password":3,"guides-en":321},{"id":4,"title":5,"body":6,"date":300,"description":301,"extension":302,"keywords":303,"meta":311,"navigation":312,"path":313,"related":314,"seo":317,"stem":318,"updated":319,"__hash__":320},"guides_en\u002Fguides\u002Fjk-bms-password.md","JK BMS Password: Default Codes, Change and Reset Guide",{"type":7,"value":8,"toc":283},"minimark",[9,13,18,21,66,69,73,87,90,94,97,116,119,123,126,166,170,173,198,201,205,211,214,229,242,246,251,254,258,261,265,268,272,275],[10,11,12],"p",{},"A JK BMS password is actually two separate codes. The Bluetooth (connection) password lets the app talk to the BMS. The settings password lets you change parameters. The factory default on most units is 1234 for Bluetooth and 123456 for settings, but check your own manual, because batches and firmware differ.",[14,15,17],"h2",{"id":16},"the-two-codes-a-jk-bms-uses","The two codes a JK BMS uses",[10,19,20],{},"Many \"password not working\" problems come from mixing these up.",[22,23,24,40],"table",{},[25,26,27],"thead",{},[28,29,30,34,37],"tr",{},[31,32,33],"th",{},"Code",[31,35,36],{},"What it unlocks",[31,38,39],{},"Commonly reported default",[41,42,43,55],"tbody",{},[28,44,45,49,52],{},[46,47,48],"td",{},"Bluetooth (connection) password",[46,50,51],{},"Connecting the app to the BMS",[46,53,54],{},"1234",[28,56,57,60,63],{},[46,58,59],{},"Settings (setup) password",[46,61,62],{},"Opening and saving the parameter screens",[46,64,65],{},"123456",[10,67,68],{},"The two are independent. Changing one does not change the other. The app asks for the settings password when you open the parameter pages, which is where the \"verify password\" prompt comes from. Defaults are reported in the JK manual, on the JK shop pages and in many DIY Solar Forum threads. They are not guaranteed for every batch, so treat them as the first thing to try, not a promise.",[14,70,72],{"id":71},"passwords-and-the-browser-connection","Passwords and the browser connection",[10,74,75,76,81,82,86],{},"When you connect from the browser with the ",[77,78,80],"a",{"href":79},"\u002F","JK Preset Studio editor",", there is no password prompt. The link uses the same JK02 Bluetooth protocol as the app, and in our tests on firmware 19 the BMS accepted reads and writes without either code: the JK app checks the codes itself. One report on an older V15 firmware says writes stopped after the settings password was changed, so this may differ on your unit. See the ",[77,83,85],{"href":84},"\u002Fguides\u002Fjk-bms-bluetooth-browser","Bluetooth guide"," for the whole routine.",[10,88,89],{},"This also means the codes are not real security against someone within Bluetooth range. Keep the BMS connected to a monitor or switch Bluetooth off if that matters for your installation.",[14,91,93],{"id":92},"how-to-change-the-passwords","How to change the passwords",[10,95,96],{},"The exact menu names change between app versions, so look for the equivalents on your screen.",[98,99,100,104,107,110,113],"ol",{},[101,102,103],"li",{},"Connect to the BMS with the current Bluetooth password.",[101,105,106],{},"Open the settings area and enter the current settings password when asked.",[101,108,109],{},"Find the password options (the app has entries for the connection password and for the settings password).",[101,111,112],{},"Enter the old code, then the new one, and confirm.",[101,114,115],{},"Disconnect and reconnect to test the new Bluetooth password. Reopen the parameter screen to test the new settings password.",[10,117,118],{},"Use a short code of letters and digits. The BMS stores each code in a 16 character field, and plain ASCII is the safest choice. Write the new codes down somewhere other than the phone.",[14,120,122],{"id":121},"jk-bms-password-not-working","JK BMS password not working",[10,124,125],{},"Try these in order.",[127,128,129,136,142,148,154,160],"ul",{},[101,130,131,135],{},[132,133,134],"strong",{},"Wrong code type."," The pairing prompt wants the Bluetooth password. The parameter screen wants the settings password. Try 1234 on the first and 123456 on the second.",[101,137,138,141],{},[132,139,140],{},"Typing issues."," Check caps lock and auto-capitalization on the phone keyboard. Passwords may be case sensitive. Watch for a trailing space.",[101,143,144,147],{},[132,145,146],{},"Changed earlier."," If someone else set up the battery, the defaults no longer apply.",[101,149,150,153],{},[132,151,152],{},"App version."," A very old or very new app can behave differently from your firmware. Update the app, or try the version recommended by the seller.",[101,155,156,159],{},[132,157,158],{},"Firmware differences."," Some users on the DIY Solar Forum have reportedly had password trouble after the V19 firmware update. If the problem started right after an update, say so when you contact support.",[101,161,162,165],{},[132,163,164],{},"Stale app data."," Some users report that clearing the app data and reinstalling lets the default settings password work again. This only resets the app side, so it will not help if the code was changed inside the BMS.",[14,167,169],{"id":168},"jk-bms-forgot-password-realistic-options","JK BMS forgot password: realistic options",[10,171,172],{},"There is no universal backdoor, and nobody should promise you one. Here is what is realistic.",[98,174,175,181,192],{},[101,176,177,180],{},[132,178,179],{},"Contact the seller or JK support"," with the BMS serial number. The serial is in the app under the About or device info page. JK support has reportedly offered a temporary password based on the serial number for owners who forgot their code, through its after-sales service pages. Availability and the exact procedure depend on your firmware and the support channel, so check the current support page rather than trusting an old forum post.",[101,182,183,186,187,191],{},[132,184,185],{},"Look for a backup."," If you exported your settings earlier, the ",[188,189,190],"code",{},".jkcfg"," file may contain the codes. See the next section.",[101,193,194,197],{},[132,195,196],{},"Ask the seller about a reset procedure"," for your hardware version. Some versions have one, many do not.",[10,199,200],{},"Do not buy \"unlock tools\" from random sellers. A BMS that controls a battery bank is not the place for untrusted firmware or dongles.",[14,202,204],{"id":203},"passwords-inside-the-jkcfg-file","Passwords inside the .jkcfg file",[10,206,207,208,210],{},"The exported ",[188,209,190],{}," is a 600 byte copy of two BMS frames. The second frame, the device info frame, has two ASCII fields of 16 characters each: the device passcode (the Bluetooth password) and the setup passcode (the settings password). So an exported file can contain both codes in plain text.",[10,212,213],{},"What this means for you:",[127,215,216,219,222],{},[101,217,218],{},"Treat an exported file like a password. Do not post it on a forum or send it to a stranger without checking it.",[101,220,221],{},"Before sharing, clear both fields in the file, or replace them with throwaway codes. Do not share a file that holds your real codes.",[101,223,224,225,228],{},"In ",[77,226,227],{"href":79},"JK Preset Studio",", these are normal editable fields on the Device tab, not read-only ones. Model, serial number, hardware and software version are read-only there, but both passcodes can be edited, and only the edited bytes change when you export. The checksums are fixed automatically.",[10,230,231,232,236,237,241],{},"Importing a file may also write the codes stored in it back to the BMS. This is unverified. To be safe, check the codes in the file before you import, so you do not lock yourself out with a code you do not remember. Clear them before sharing the file. For the full backup and import routine, see ",[77,233,235],{"href":234},"\u002Fguides\u002Fjk-bms-export-import-settings","export and import JK BMS settings",". Once you can open the parameter screen, the ",[77,238,240],{"href":239},"\u002Fguides\u002Fjk-bms-lifepo4-settings","LiFePO4 settings guide"," is a good next step.",[14,243,245],{"id":244},"faq","FAQ",[247,248,250],"h3",{"id":249},"is-the-jk-bms-password-the-same-as-the-bluetooth-pin","Is the JK BMS password the same as the Bluetooth PIN?",[10,252,253],{},"Not exactly. The connection password the app asks for is the BMS \"device passcode\". It is separate from the settings password. Your phone's own Bluetooth pairing, if it asks for one, is handled by the phone.",[247,255,257],{"id":256},"does-a-firmware-update-reset-the-password","Does a firmware update reset the password?",[10,259,260],{},"It should not, but some users have reported password problems after updates. Export your settings before updating, and note both codes.",[247,262,264],{"id":263},"can-i-read-the-password-from-the-file","Can I read the password from the file?",[10,266,267],{},"Yes, if the file holds the codes in the device info frame, they are stored as plain text. Open the file in the editor and look at the Device tab to see what it contains.",[247,269,271],{"id":270},"should-i-change-the-default-codes","Should I change the default codes?",[10,273,274],{},"Yes, if others can reach the battery. Anyone near the BMS with a phone can try 1234 and 123456.",[10,276,277,282],{},[77,278,279,280],{"href":79},"Connect your BMS or open your ",[188,281,190],{}," in the editor to check which codes it holds before you share a file or import it.",{"title":284,"searchDepth":285,"depth":285,"links":286},"",3,[287,289,290,291,292,293,294],{"id":16,"depth":288,"text":17},2,{"id":71,"depth":288,"text":72},{"id":92,"depth":288,"text":93},{"id":121,"depth":288,"text":122},{"id":168,"depth":288,"text":169},{"id":203,"depth":288,"text":204},{"id":244,"depth":288,"text":245,"children":295},[296,297,298,299],{"id":249,"depth":285,"text":250},{"id":256,"depth":285,"text":257},{"id":263,"depth":285,"text":264},{"id":270,"depth":285,"text":271},"2026-10-02","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.","md",[304,305,306,307,308,309,310],"jk bms password","jk bms default password","jk bms password reset","jk bms password not working","jk bms forgot password","jk bms verify password","jk bms settings password",{},true,"\u002Fguides\u002Fjk-bms-password",[315,316],"jk-bms-export-import-settings","jk-bms-lifepo4-settings",{"title":5,"description":301},"guides\u002Fjk-bms-password","2026-10-04","BkUUyOad8YvrNaMW09AcURPWs6_XYjvAiCJs-stwXn4",[322,326,330,334,338,341,344,348,352,356,360,361,365,369,373,377],{"path":84,"title":323,"description":324,"date":319,"updated":325},"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":327,"title":328,"description":329,"date":300,"updated":319},"\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":331,"title":332,"description":333,"date":300,"updated":325},"\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":335,"title":336,"description":337,"date":300,"updated":319},"\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":234,"title":339,"description":340,"date":300,"updated":319},"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":239,"title":342,"description":343,"date":300,"updated":319},"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":345,"title":346,"description":347,"date":300,"updated":325},"\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":349,"title":350,"description":351,"date":300,"updated":319},"\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":353,"title":354,"description":355,"date":300,"updated":319},"\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":357,"title":358,"description":359,"date":300,"updated":319},"\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":313,"title":5,"description":301,"date":300,"updated":319},{"path":362,"title":363,"description":364,"date":300,"updated":319},"\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":366,"title":367,"description":368,"date":300,"updated":319},"\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":370,"title":371,"description":372,"date":300,"updated":319},"\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":374,"title":375,"description":376,"date":300,"updated":325},"\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":378,"title":379,"description":380,"date":300,"updated":319},"\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.",1791151315862]