Customer Support

Shipping and Delivery

What is the processing time?

The item’s processing time is the time from receiving your order to physically dispatching it. After receiving your order, we conduct rigorous Quality Control checks and tests in order to ensure the product’s quality prior to shipment to meet your satisfaction. It normally takes within 24 hours of business day for us to process your order. However, please note that the processing time can also be affected by the stock status of individual items, the time of the year, national holidays, etc. If your order includes very popular items that are experiencing stock availability issues, then the order can take 1-3 business days to process and dispatch. We apologize in advance for any inconvenience caused by these delays and thank you for your patience.

Shipping time

For detailed information on standard delivery and express delivery: Standard Shipping: 10-25 business days; Express Shipping: 5-15 business days; * The shipping time is estimated and commences from the date of shipping, rather than the date of order, and can take longer than expected date due to an invalid address, the customs clearance procedures or other causes. *For Express Shipping: Possible tariffs and other possible related costs are borne by the customers

About Tax

Shipments from all of our warehouses are delivery duty unpaid. Therefore, any and all customs or import duties are charged once the parcel reaches its destination country. If any,these charges must be paid by the customers.Customers take full liability for all return shipment costs, customs charges and handling fees should they refuse to accept a parcel due to import duties or taxes. Please note that according to customs regulations, JKESS.DE cannot declare purchased items as a gift or list an amount that lower than the actual product price.

Returns & Exchanges

How long can I return the items?

Returns can be made within 14 days from the date you’ve received all your items. Please contact us immediately. No returns are made after 14 days from the date you’ve received your items.

Conditions

All item(s) must be unworn and in the original condition with the original packaging and all tags attached. Any item(s) that appear to have been worn, washed, or altered in any way will not qualify for a refund. The original shipping cost (if any) is non-refundable, in most cases. All used items cannot be returned. The return shipping fee will be at your own cost. Please contact sales@jkess.de for the returns.

How do I apply for an after-sales?

Sign into your jikongbms.com account. Find the order in My Orders, Copy the order number.Send us an email and let us know the item(s) you would like and the reason(s) to request the refund/return. We’ll be in touch with solutions after we receive your information. Important notice: To return a package, please contact our Customer Service for a return address. Please do not send your return to the sender’s address on your package. Please make sure you don’t include items not from JKESS.DE by accident in your return package. We will not be responsible for sending back those items to you.

Refunds

PayPal account refunds: Up to 48 hours Credit card refunds: Between 7-14 business days For some debit and credit card refunds to the original payment account cannot be made. In such cases, we will request customers to provide us with a PayPal account in their name to complete refunds. Thank you for your understanding.

Exchanges

Please contact sales@jkess.de for the Exchanges.

FAQ

JKESS brings together a team of professional BMS engineers with over a decade of experience in the electronics and battery management field. Donec pede justo, fringilla vitae, eleifend acer sem neque sed ipsum. Nam quam nunc, blandit vel, ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu

1. Continuous Discharge Current
The BMS continuous discharge current rating must exceed your device’s maximum continuous operating current by a 20%–30% margin.

For example: if your load draws 30A continuously, choose a BMS rated at least 40A.

2. Peak Current
For momentary high-current events (e.g., motor startup), the BMS peak current rating should be 2–3x the continuous current, and its duration must cover the device’s startup time.

For example: a 40A BMS typically supports a peak of ~80–120A for a few seconds to handle motor startup surges.

Series Connection: Total pack current = single cell current. Current is identical throughout a series circuit.
Parallel Connection: Total pack current = single cell current × number of parallel cells.
Series-Parallel Combination: Total pack current = single cell current × number of parallel cells per block.
Example — A 20S Battery Pack with 3 Parallel Cells per Block
For a battery pack built with 20 cells in series and 3 cells in parallel per block:

3 parallel cells per block means the pack current = single cell current × 3
If each cell delivers 20A, total pack current = 20A × 3 = 60A
Recommended BMS: rated at least 80A (with 20%–30% margin)
Recommended usable load = 70–80% of BMS rated current for long-term reliability
Peak protection current activates for a few seconds to handle motor startup or surge loads

Protection CurrentTypical Use CaseCommon Applications
40ALight loadSmall e-bikes, electric scooters, portable power stations
60ALight to medium loadE-bikes, electric skateboards, backup power systems
80AMedium loadHigh-performance e-bikes, energy storage systems
100AMedium to high loadElectric vehicles, industrial battery packs
120AHigh loadHigh-voltage e-bikes, EVs, large energy storage
150AHigh loadLarge EVs, commercial energy storage
200AVery high loadHeavy-duty EVs, large-scale energy storage
300AUltra high loadIndustrial-grade systems, large battery arrays

If you plan to connect your BMS to an inverter for off-grid solar systems or home energy storage (ESS), please note:

  •  CAN communication is required for most inverter brands. You must choose a BMS with CAN support — i.e., the HC or HCR version.
  •  For off-grid solar or home ESS applications, we strongly recommend the dedicated JKBMS Inverter BMS series, which is purpose-built for inverter integration.
  •  Standard BMS versions without CAN are not compatible with inverter communication protocols.

Supported Inverter Brands & Protocols

The following list covers the mainstream inverter brands currently supported by JKBMS. If your inverter brand is not listed, please contact us.

BrandProtocolCommunicationNotes
DeyeLow-voltage hybrid inverter CAN protocolCANBUS-500KBattery Setup Menu → Lithium; Advanced Function → BMS_Err_Stop
PYLONPYLON CANBUS Protocol V1.2 / Low voltage RS485CANBUS-500K / RS485-9600
GrowattCAN Bus REV_05 / RS485 ESS Protocol V2.01CANBUS-500K / RS485-9600Set 05 to LI; Set 36 to 1 for CAN or 51 for RS485
VictronCAB-BUS BMS Protocol 201707CANBUS-500KVia Cerbo GX
INVTCAN Bus Protocol V1.02CANBUS-500KBD5KTL-RL1
GoodWeLV BMS Protocol V1.7CANBUS-500KGW5000-ES-20; Select GoodWe → SECU-A5.4L×1
SMAFSS-ConnectingBat-TI-en-10 V1.0CANBUS-500K
VoltronicVoltronic Power Inverter & BMS 485 Protocol V0RS485-9600Long press SET → Set 05 to LIB
SRNEPACE BMS Modbus Protocol for RS485RS485-9600Set 39 to BMS; Set 32 to BMS; Set 33 to WOW
MUST
SOFAR

 This compatibility list will be continuously updated. Don’t see your inverter? Contact us.

Standard Features (All JKBMS Smart BMS)

Note: The features below apply to the Smart BMS series. The JKBMS Inverter BMS is a fully integrated solution with all features built-in — see the dedicated Inverter BMS section above.

  •  LCD Bluetooth status indicator
  •  APP Bluetooth remote operation & monitoring
  •  Battery capacity calculation (SOC)
  •  High-precision voltage acquisition (±3mV)
  •  High-precision current acquisition
  •  LCD display interface support
  •  Accurate time logging

Protection Features

  •  Charge overcurrent protection
  •  Charge overvoltage protection
  •  Charge over-temperature protection
  •  Low-temperature protection during charging
  •  Discharge overcurrent protection
  •  Discharge undervoltage protection
  •  Discharge over-temperature protection
  •  Short-circuit protection

Optional Add-ons (Smart BMS only — not applicable to Inverter BMS)

The following features are available on selected Smart BMS models or via custom order. Please contact us to discuss your specific requirements:

  •  RS485 communication
  •  CAN communication
  •  Parallel expansion function
  •  Alarm function
  •  Heating function
  •  ACC detection function

JKBMS Inverter BMS — Fully Integrated Features

The JKBMS Inverter BMS is purpose-built for inverter and ESS integration. All the following features are fully integrated — no add-ons required:

  •  Active cell balancing
  •  Bluetooth connectivity
  •  NTC temperature sensing
  •  RS485 communication
  •  CAN communication
  •  Display interface
  •  Heating function
  •  Dry contact (alarm output)
  •  Charge overvoltage protection
  •  Overcurrent protection
  •  Short-circuit protection
  •  Battery parallel current limiting
  •  Discharge pre-charge

Need help choosing? Contact us with your battery specs and we will recommend the right model.

Please contact sales@jkess.de for further help. We will do our very best to help you and reply to all messages within 24 hours.