Skip to content
BK8K-RC — 25.6 V / 320 Ah compression box with BMS+, front viewBK8K-RC — a single column of 8 EVE MB31 cells, top view
Type designation · BK8K-RC

LiFePO4 battery
25.6 V / 320 Ah

LiFePO₄ battery in a compression box, 25.6 V / 320 Ah / 8.0 kWh, 8× EVE MB31-D06-01. Bluetooth + CAN + RS485 + RS232. JK BMS active balancer, handmade in the Czech Republic, 4-year warranty on cells.

Compression box 8× EVE MB31-D06-01 BluetoothCANRS485RS232
Energy
8 kWh
Capacity
320 Ah
Cycle life
8,000 cycles
Cell warranty
4 years
Price excl. VAT
CZK 35,500
CZK 42,955 incl. 21 % VAT
Made to order

Variants of this pack

BK8K-RCBTCANRS485RS232CZK 35,500
Description

What it's good for.

EVE MB31 cells clamped in a compression box for 24 V PV and off-grid systems. The BK8K-RC variant with an advanced BMS integrates fully into a Victron system (Cerbo GX, VRM).

A 25.6 V / 8 kWh battery pack in a compression box in the special Victron (BMS+) version. It consists of 8 prismatic LiFePO₄ EVE MB31 cells connected in series (8S1P, 320 Ah pack) with an advanced control unit and an extended communication panel. The pack is intended for PV systems, backup power and off-grid operation, and is optimised in particular for direct integration into a Victron environment (VRM, Cerbo GX via VE.CAN).

Advantages of LiFePO₄ chemistry: high safety and resistance to thermal runaway, a long service life of thousands of cycles, suitability for deep cycling and stable operation. Safety is handled by an advanced BMS control unit that continuously monitors voltage, current and temperature and protects against overvoltage (OVP), undervoltage (UVP), overcurrent (OCP), short circuit (SCP) and unsuitable temperatures. The 2 A active balancer continuously equalises the voltage between the cells, extending the service life of the whole pack.

Compression box version (Victron / BMS+): the compression box keeps the cells clamped for optimal performance and service life, especially under heavy load, and can be installed horizontally or vertically. This version also has an extended communication panel with LED SOC indication, DIP switches for parallel connection, a DRY contact (DCT) for switching external devices (e.g. a generator based on SOC) and full integration into VRM through communication with the Victron Cerbo. It supports parallel connection of several batteries using cascaded RS485 communication.

Installation and operation: installation must only be carried out by a qualified person. For the compression box, power cabling with a cross-section of at least 1× 50 mm² (for currents up to 160 A) and appropriate fusing is recommended; once the box is in place, the 3 nuts on its top plate must be loosened by ¼ turn. We recommend connecting the battery while switched off and switching it on only afterwards. All operating data is available in the BAKOM BMS app (Bluetooth). For a long service life, use the capacity within the 10–100 % range, keep the cells within their optimum temperature range (ideally around 25 °C) and charge to 40–80 % for storage. Each pack is built individually or to order, according to the customer's needs.

This variant (BK8K-RC): Communication: Bluetooth, CAN, RS485, RS232; LCD display optional.

Specifications

Technical specifications.

Values for the BK8K-RC variant. The charge and discharge limits correspond to the BMS settings the battery has when it leaves the workshop.

Nominal voltage
25.6 V (8S)
Capacity
320 Ah
Energy
8 kWh
Chemistry
LiFePO₄ (lithium iron phosphate)
Cells
8× EVE MB31-D06-01
BMS
JK BMS+ with communication port panel
Balancer
active, 2 A
Continuous current (charge and discharge)
160 A
Peak current
200 A / 20 s
Cycle life
8,000 cycles to 70% capacity
Charging — temperature
+1 to +55 °C
Discharging — temperature
−22 to +55 °C
Charging: absorption / float
27.9 V / 27.4 V
Discharge cut-off (recommended)
24.0–24.5 V
Communication
Bluetooth, CAN, RS485, RS232
LCD display
optional
Build
Compression box
Dimensions
70×27×26 cm
Weight
51.5 kg
Production
handmade, Czech Republic
Warranty
4 years on the cells

Energy = capacity × average discharge voltage (3.125 V per cell), i.e. the energy the battery delivers between the BMS limits. Cycle life is stated by the cell manufacturer for 25 °C; actual life depends on operating conditions. The 4-year warranty applies to the cells; the BMS and other electronics are covered as set out in the warranty certificate.

What you get

Ready to connect.

Each battery leaves the workshop with its BMS set up and after a final test. Every battery comes with a report of the measured cell capacity and a warranty certificate.

  • Battery with the BMS configuredWe set the protections according to the battery type and the communication according to your inverter.
  • Cell capacity reportMeasured capacity and internal resistance of each cell, and the result of the final test.
  • Manual and warranty certificateWiring procedure, recommended inverter settings and warranty terms.
  • Inverter cableIncluded with 48 and 51.2 V batteries with BMS+ according to the ordered configuration; for other batteries at extra cost.
  • BAKOM BMS app and BAKOM CloudBattery status and cell voltages on your phone via Bluetooth, history and settings on the web. Free for BAKOM batteries.
Frequently asked questions

What you ask us.

Didn't find your answer? Call or write to us — we'll help you choose and connect it.

When will I receive the battery?

We build batteries by hand to order and do not keep them in stock. After your inquiry we confirm the current lead time and put you in the order queue — the reservation is free and non-binding. We contact you before production starts.

Do I pay a deposit?

No. We build and test the battery, then send the invoice and dispatch the battery once payment has arrived. Smaller batteries go by PPL, heavier ones on a pallet; the shipping cost is stated in the quote. Collection in person is possible by arrangement near Klatovy or near Ostrava.

Will the battery communicate with my inverter?

CAN variants communicate with Victron, Deye, Growatt, GoodWe, MUST, Luxpower and other inverters, and via RS485 with, for example, Voltronic inverters. With a Victron system (Cerbo GX), it is the CAN variants that communicate. Our batteries are low-voltage — they do not work with high-voltage (HV) hybrid inverters. Send us your inverter type and we will check.

Can I charge the battery in winter?

Below +1 °C the BMS blocks charging to protect the cells and allows it again above +4 °C. Discharging is possible down to −22 °C. For unheated spaces there are variants with HEAT heating (suffix H), which warm the cells before charging.

What charging voltage should I set?

12.8 V: absorption 14.1 V, float 13.8 V · 25.6 V: 27.9 / 27.4 V · 51.2 V: 55.8 / 54.7 V · 48 V (15 cells): 52.3 / 51.3 V. The BMS protection voltage (3.56 V per cell) is not a charging target. For 15-cell batteries, do not use profiles for 51.2 V or for lead-acid batteries.

Is the inverter communication cable included?

For 48 V and 51.2 V batteries with BMS+ (RC variants), yes, depending on the configuration ordered. For 12.8 V and 25.6 V packs we supply it at extra cost or make one to measure.

Can I add another battery later?

Variants with BMS+ (BK8K-RC and the 48/51.2 V RC series) can be connected in parallel; up to 16 batteries with the same BMS version can be addressed. Each battery is connected separately to the DC busbar with cables of the same length and cross-section — daisy-chaining power cables from battery to battery is not permitted. For more than two batteries we go through the set-up with you in advance.

What is the difference between the AkuBox and a compression box?

The compression box keeps the cells clamped, which benefits their life especially under high load; it can stand horizontally or vertically. It is an open design, so it belongs in a lockable technical room. The AkuBox is a closed enclosure that protects the battery from damage and unauthorised tampering — made of plastic for 12.8 and 25.6 V. The metal AkuBox BK16A-RC also has a built-in display and an isolator switch.

How many cycles will the battery last?

Packs built from EVE LF280K and MB31 cells last 8,000 cycles until capacity drops to 70 %, 105 Ah packs 4,000 cycles to 80 % (cell manufacturer's data at 25 °C). Actual life depends on temperature, currents and depth of discharge.

How should I store the battery over winter?

If the battery will be out of use for more than a week, switch it off. Store it in a dry place, charged to roughly 40–80 %, and top it up every three months. Never leave it fully discharged.

How can I monitor the battery remotely?

The BAKOM BMS app connects to the battery via Bluetooth. The BAKOM Cloud web portal then keeps your batteries, measurement history and settings in one place — you add a battery to your account with the QR code on its label. More on the App page.

Am I allowed to change the BMS settings?

We set the protection parameters in the workshop according to the battery type. Normal user functions in the BAKOM BMS app do not void the warranty; changing the protection configuration, changing the administrator password or modifying the wiring does.

Inquiry · BK8K-RC

Interested in the BK8K-RC?
Write to us.

Add the quantity, the type of inverter or appliance and your timing. We check that the pack suits your system and send a quote with a delivery date.

Email
baterie@bakom.czInquiries, orders and technical questions
Bronislava Baxová
+420 737 344 853Orders, lead times, invoices and dispatch
Petr Baxa
+420 603 552 577Production, wiring of batteries and Deye inverters
Michal Komenda
+420 602 564 571Technical matters, off-grid systems and Victron, BAKOM BMS app
Workshops
Svrčovec near Klatovy and Krmelín near OstravaVisits and collection by appointment only
Requested productBK8K-RCLiFePO₄ battery 25.6 V / 320 Ah, compression box

We will use your details only to handle your inquiry. Privacy policy.