ENGINEERING NOTES
Notes on the decisions that come before a part number
Each note takes one decision and works it to the end: the measurement, the arithmetic, the failure mode, and the point at which a product page has to be opened. They are written for the person holding the cells, not for the person choosing a brand.
Why the decision usually comes before the catalog
Most orders that need correcting were placed against the wrong constraint. A board sized from battery capacity instead of the inverter rating, an enclosure chosen on amp-hours instead of stack length, a cabinet specified in kWh with no kW figure beside it, a cable picked because the plug fits. Each of those is a decision made in the wrong order, and none of them are visible on a product page.
So these notes settle the constraint first. When one is finished it points at the catalog, the model index or the enclosure kits, and the shortlist is short. Where a note and a product page disagree, the product page and the written quotation are the ones that bind.
ENGINEERING NOTES
Settle the decision, then pick the part
Check a JKBMS source
Check a JKBMS listing against what a reseller cannot restate: the four segments of the model code, the version the board reports itself, the visible port set, and a quotation that names its own exclusions.
Read guideNAME TO PARTFrom brand name to part
All four spellings return the same hardware, so none of them narrows anything. This maps the term you searched to the artefact you were actually after: a model code, a manual, a firmware note or a cable.
Read guideORDERINGHow ordering works
Two order paths run on this catalog. Work out which one a product uses, what shipping costs to your destination, which currency you will be charged in, and what has to be fixed before payment.
Read guideENCLOSURE DOCSBattery box documents
Find the JKESS enclosure document that matches the format you were shipped, and work out the four cell measurements an enclosure manual assumes you already checked.
Read guidePEAK SHAVINGSizing peak shaving
Work peak shaving out of interval data: find the billing demand window, measure the energy above the threshold, size kW and kWh separately, and stop the recharge from setting the next peak.
Read guideTHERMALAir or liquid cooling
Estimate what a battery cabinet actually has to reject, judge the design on cell-to-cell temperature spread rather than average temperature, and price in what each cooling system costs to keep working.
Read guideBMS ARCHITECTUREWhat a BMU is
BMU means different things in different datasheets. Establish what a specific controller does from its I/O list, count units from channels rather than from kWh, and find where the interlock loop really terminates.
Read guideSOURCINGComparing ESS quotes
Normalise C&I ESS quotations before comparing price: usable against nameplate energy, what the warranty actually measures, the line items that fall outside the scope, and who owns the integration boundary.
Read guideAPP AND BLUETOOTHJKBMS app and Bluetooth
Connect the JKBMS app over Bluetooth, understand pairing behaviour and permissions, and work through the connection failures reported most often.
Read guideRS485 AND CAN WIRINGJK BMS RS485 and CAN wiring
Identify the RS485 and CAN ports on a JK BMS, verify the pinout against the manual for your model, and avoid the wiring mistakes that damage a port.
Read guideFIRMWARE AND PARAMETERSJKBMS firmware and parameters
Understand how JKBMS firmware versions affect available parameters, what to record before changing settings, and how to avoid an unrecoverable configuration.
Read guideFAMILY TABLEBD, PB, B1A and B2A side by side
One table showing what each family is built around, so a shortlist takes a minute instead of a browse.
Read guideENCLOSURE FITFitting cells into an enclosure kit
Measure the cells before shortlisting a box: stack length with compression, height over the terminals, mass and rack loading.
Read guideBOARD SELECTIONNarrowing the catalog to one code
Work from the pack and the inverter rating down to a handful of codes instead of browsing the list.
Read guideBD OR PBWhich family the project needs
Local monitoring or an inverter protocol link. That question decides the family before anything else does.
Read guideBALANCE CURRENTHow much balancing a pack needs
Balance current is a rate. Match it to how fast the pack drifts and how much idle time it has to recover.
Read guideBUS CHOICECAN or RS485 for the link
The device at the far end decides the bus. Confirm pinout, bitrate and protocol profile before buying a cable.
Read guideHIGH-VOLTAGEWhere contactor authority sits
Split responsibilities between module slaves and the cluster master, and find what nothing in the design owns yet.
Read guidePROJECT INPUTSWhat to fix before requesting a cabinet quote
The decisions that have to be settled first, and the ones that can safely stay open until the design review.
Read guideREFERENCE
Short answers, written for the bench
Identify a JKBMS
Read a JKBMS model code, confirm what the board on the bench actually is, and match it to the right product page before ordering a replacement.
Read itNAMINGJK BMS naming
Sort out the JK BMS, JK-BMS, JKBMS and JIKONG spellings, and learn which parts of a listing actually identify the hardware.
Read itNAMINGJIKONG BMS
Why JIKONG and JKBMS appear on the same hardware, and how to read a board label when the two names are mixed.
Read itSERIES REFERENCEJK-BD series
Match a JK-BD model to a real battery pack by string count, continuous current, balance current and the port set the installation needs.
Read itSERIES REFERENCEJK-PB series
Select a JK-PB model by the inverter it has to talk to, then confirm the cable, pinout and protocol before the pack is built.
Read itSERIES REFERENCEJK-B2A series
Decide whether a pack needs 2A active balancing, and what the JK-B2A family costs in heat and space to deliver it.
Read itCABLESInverter cables
Pick a JKBMS communication cable by protocol and pinout rather than by connector shape, and avoid the swaps that damage a port.
Read itSELECTIONActive balancing
Work out the active balance current a pack needs from cell matching, capacity and duty cycle, instead of buying the highest number available.
Read itSELECTIONLiFePO4 BMS
Translate a LiFePO4 pack design into BMS requirements: series count, current, temperature sensing, and the charge behaviour the chemistry needs.
Read itINTEGRATIONInverter integration
A practical order of operations for BMS to inverter communication, from confirming protocol support to isolating a failed handshake.
Read itCOMMUNICATION INTENTCAN vs RS485
Decide whether a BMS link should be CAN or RS485, and confirm the pinout, bitrate and protocol before ordering a cable.
Read itSYSTEM NOTES
Three system shapes, worked end to end
Four numbers, then a build order
Series count, charge voltage, continuous current and protocol have to agree first. After that a home pack is a sequence where the order genuinely matters.
Open the noteINVERTER LINKGetting a BMS and an inverter to agree
Confirm the protocol revision before the hardware, isolate a silent link from the pack outward, and know what a fully working link should be doing.
Open the noteC&I CABINETSizing a cabinet against the demand bill
kW and kWh are separate answers and the tariff decides both. Then cooling, grid equipment and fire strategy follow in an order that resists reworking.
Open the note