Pictured: the BK8K-RC variant
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. JK BMS active balancer, handmade in the Czech Republic, 4-year warranty on the cells.
- Energy
- 8 kWh
- Capacity
- 320 Ah
- Cycle life
- 8,000 cycles
- Cell warranty
- 4 years
Variants of this pack
Other voltage or capacity · Compression box
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).
The BAKOM 25.6 V / 320 Ah battery pack (8 kWh) in a compression box, built from 8 EVE MB31 grade A cells (8S), for 24 V off-grid and PV systems and electric boat motors.
The compression box keeps the cells clamped as recommended by the cell manufacturer, which benefits their service life, especially under heavy load. It can stand horizontally or vertically. Once it is in place, the three nuts on the top plate are loosened by a quarter turn; they are not retightened during operation. Connect each terminal with its own copper cable, at least 50 mm² for currents up to 160 A.
The battery is managed by a JK BMS with a 2 A active balancer that guards against overvoltage, undervoltage, overcurrent and short circuit and monitors cell temperature. Recommended charging: absorption 27.9 V, float 27.4 V. The standard BMS has no built-in pre-charge — when connecting to an inverter with large capacitors, use an external pre-charge circuit. You can monitor the battery in the BAKOM BMS app via Bluetooth.
Installation may only be carried out by a qualified person. Connect the battery while it is switched off and through suitable fusing.
This variant (BK8K): Bluetooth communication; LCD display optional.
Technical specifications.
Values for the BK8K 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 B2A8S20P
- 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
- LCD display
- optional
- Build
- Compression box
- Dimensions
- 45×40×25 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.
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.
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.
Interested in the BK8K?
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.
- 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