Residential battery storage
i3 BESS
Home storage from BMW i3 batteries and Samsung SDI cells — reliable, safe and ready for PV, backup and EV charging.
Three capacity variants i3 BESS 60 / 94 / 120 (BMW i3 60/94/120 Ah modules) cover typical household demand and larger residential projects. Second-life automotive cells deliver build quality, long life and a sensible total cost of ownership.
- Designed and built in the Czech Republic
- Samsung SDI automotive NMC cells
- 10-year warranty · IP 65/55 · 15 kW
i3-60 · i3-94 · i3-120
18–38 kWh · expandable to 152 kWh per inverter
10-year warranty
On the battery system
Samsung SDI NMC
Automotive Tier 1 cells
Up to 152 kWh
Per inverter expansion
Second life
Circular economy in practice
Why i3 BESS
Built for homes with PV that want to maximise self-consumption, cut electricity bills and keep critical loads backed up.
Automotive quality for the home
At the core are second-life BMW i3 batteries with Samsung SDI Li-NMC cells designed for demanding EV duty — durability, safety and longevity are built in.
We always deliver cells with capacity above 80% of original production values. Every system is checked and prepared for long-term stationary use.
Compact 398 V platform
Nominal voltage 398 V (range 320–398 V) and rated charge/discharge power 15 kW on all variants — ideal for household loads, heat-pump support and EV charging.
Cabinet 167 × 99 × 17 cm (H × W × D) with 30 cm clearance each side. IP 65/55, passive cooling with BMS regulation, CAN/RS485 communication.
Smart control and monitoring
Built-in web UI, Ethernet, activity charts and remote management. The BMS protects cells against temperature, under/overvoltage and overcurrent, with passive balancing.
Compatible with a wide range of high-voltage hybrid inverters for fast integration into common PV setups.
Three capacity variants
Size for household demand. Expandable to 152 kWh per inverter (up to 2 batteries per input, up to 4 with a dual-input inverter).
Battery packs in installation (1–4)
Voltage
398 V
Power
15 kW
Capacity
18 kWh
Weight
350 kg
i3 BESS — technical specification
Parameters from the current datasheet (v20260608). Capacity follows BMW i3 module generations (60 / 94 / 120 Ah).
| i3 60 | i3 94 | i3 120 | |
|---|---|---|---|
| Battery module type | BMW i3 60 Ah | BMW i3 94 Ah | BMW i3 120 Ah |
| Cell manufacturer | Samsung SDI (NMC automotive) | ||
| Capacity | 18 kWh | 28 kWh | 38 kWh |
| Nominal voltage | 398 V | ||
| Voltage range (0–100 % SoC) | 320 – 398 V | ||
| Rated charge / discharge power | 15 kW | ||
| Weight | 350 kg | ||
| Cabinet dimensions (H × W × D) | 167 × 99 × 17 cm (30 cm clearance each side) | ||
| Temperature range | −20 to +35 °C, non-condensing humidity | ||
| Ingress protection | IP 65 / 55 — indoor and outdoor | ||
| Cooling | Passive, BMS regulation | ||
| Inverter connection | CAN / RS485 | ||
| Warranty | Extended 10-year warranty | ||
Expandable capacity up to 152 kWh per inverter. Second-battery expansion and module-capacity upgrade available.
Safety and BMS features
A full set of protections and monitoring — as important as capacity itself.
Smart passive balancing
Keeps cells balanced and extends pack lifetime.
Temperature protection
Protection against low and high temperature in real time.
Overvoltage & deep discharge
Multi-stage electrical protection including dual-pole disconnect.
Web UI remote
State of charge, statistics and charts in the web interface with remote oversight.
Short circuit & overload
Safe operation even under non-standard installation conditions.
Capacity expansion
Second battery, module upgrade and paralleling up to 152 kWh.
Where i3 BESS excels
Homes and residences
- · Store PV surplus and raise self-consumption
- · Cut electricity costs and enable spot trading
- · Backup for critical loads
- · Efficient EV charging
Smaller sites
- · Peak shaving and lower demand spikes
- · Complement to AC charging stations
- · Parallel growth without changing platform
- · Sustainable second-life with strong TCO
Let us size the right i3 BESS capacity for your home or project.
For PV and hybrid integration we use established high-voltage inverter brands. i3 BESS is compatible with the following.
