The battery is designed and produced by VELOKS. Only new quality cells from Panasonic is used. For 1, 2 and 3 kWh batteries NCR18650PF 2900 mAh are used, and for 4 kWh NCR18650B 3400 mAh are used.
The batteries consist of 16 “cells blocks” in series, i.e. 60 V nominal. Each “cell block” consist of either 6, 12, 18 or 21 matched cells in parallel. The cells are connected via 100% pure nickel strips that are spot welded to the cells. To ensure equal current load to each individual cells, the main power wires are connected to the cells blocks by means of a solid cobber bus, and “cells blocks” are interconnected in series between each individual cells by nickel strips. The battery box is a sandwich construction that is made of carbon fiber as the outside layers, Kevlar as the middle layers, and fiber glass as inside layers. This ensures a very strong and stiff, yet crack resistant box, which is electrical isolated.
The battery is protected by means of a battery management system (BMS). The BMS will limit the charge current to 10A and limit the discharge current to 80A to protect the battery. Also when charging the battery, the “cells blocks” are automatically balanced when the battery is charged to 100%.