Stromtank ultimate off grid power system update

My post of Stromtank independent power source created a lot of interest. Here is in-depth official information about this $30.000 power bank with The Intelligent Battery Management System (BMS). A newly active BMS was developed together with the Frauenhofer Institut, the German research establishment and provides effective balanced battery charge and discharge. By using this high-tech system, maximum efficiency and maximum durability of the power storage is achieved.
The most important facts to know about Stromtank:
Stromtank = a tank to store power inside state-of-the-art batteries Purpose: supply high value equipment with pure + stable AC-grid power to achieve best quality of audio- / video systems.

Operation mode:

1. on-grid-function – connected to grid
– limited current is taken from the grid to supply hifi-system (max. 6A)
– current pulses from hifi-system are absorbed from the battery
– nearly no interaction between audio-/ video-setup
– automatically recharging of batteries while listening to music
2. off-grid-function – completely disconnected from grid
– power supply totally from high-power battery pack with pure-sign wave converter
– Stromtank creates stable AC-amplitude, pure sine wave + crystal controlled frequency
– mechanical switch to recharging-mode – no interruptions while listening to music up to 8 hours (depending on hifi-consumption it can be even more)

Lithium Iron Phosphate (LiFePO4) – Tomorrow’s technology today

State of the art battery technology with significant advantages over the usual Li-ion, lead or lead-gel batteries: The Lithium iron phosphate battery is a further development of the lithium- ion battery.
LiFe-PO4 cells deliver very high continuous service charge currents and very high power handling (up to 25C). High charge currents (0.5C – 3C) are possible.
In contrast to conventional Li-ion cells, no metallic lithium separates out when overloaded and no oxygen is released (risk of explosion). In case of the Lithium iron phosphate battery, the so-called thermal runaway is not possible.

The LiFe-PO4 cells are intrinsically safe, environmentally friendly, very cycle-resistant and lightweight. The excellent load capacity and a long service life speak for the future of this technology.


– very long life (> 20 years possible)
– up to 10,000 cycles – with low DOD (depth of discharge)
– 5 times more cycles than lead or lead-gel batteries
– up to 6,000 charge cycles at 60% DOD (equivalent to 16 years with a daily
charge/discharge, after that at least another 80% of battery capacity)
– 93% efficiency
– up to 100% DOD possible (90% effectively usable)
– high current capacity
– absolutely environmentally friendly and maintenance-free
– no fire hazard – explosion proof, since non-oxygen-reactive
– modular system concept – extendable at any time and interchangeable
– high safety standards confirmed by relevant certificates
– lightweight


+ better efficiency
+ lower self-discharge
+ high number of cycles & long life cycle + completely maintenance free
+ lower weight & volume
+ very good environmental impact
+ extremely economical and non-aging

The Intelligent Battery Management System (BMS)

A newly active BMS – self-developed together with the Frauenhofer Institut, THE German research establishment – provides an effective balanced battery charge and discharge. By using this high-tech system, maximum efficiency and maximum durability of the power storage is achieved.
Key features: cell protection, load control, load management, determining the charge state, determination of cell health, thermal management, interfaces for communication.

The Balancer

The balancer is responsible for the active cell voltage balancing. It checks each individual cell and ensures that the cells reach the optimal state of charge. Through this technique, there is no varying burden on individual cells when current is drained. Thus, the maximum available power is obtained at all times.
Individual cells can not be overloaded. Therefore the balancer is largely responsible for the life and service life of a storage system.
model: S 5000
norm finish: meteorite-gray with diamond pixels
other finish: additional charge of 600,- Euro / unit
from 6 units of same finish: no additional charge
other finishes
lead-time: 10 – 14 weeks (depends on quantity-order)
dimensions (whd): 480 x 580 x 590 mm / 19” x 23” x 23” 
weight: 115 kg / 253 Ib
shipping dimensions (whd): 710 x 610 x 760 mm / 28” x 24” x 30” 
shipping weight: 150 kg / 330 Ib
MSRP: USD 30.000,-
warranty: 3-year limited warranty for electronical parts, battery cells, inverter and BMS under normal wear and tear and usage