Abstract: Electrochemically regenerated RuO.sub.4 (or corresponding oxides of Os, Ir, Rh) is used in the decomposition of matter, especially matter containing organic material. The method has particular advantage in dealing with compounds containing chlorine and, in a development, provides for the removal of heteroatoms N, Cl P, As, S, avoiding contamination with unoxidised organics and/or Ru (or Os, Ir, Rh as the case may be).

Abstract: Excessive charging of the weaker cells in a battery of lithium cells, during potentiostatic charging, is prevented by providing each cell (S) with a bypass circuit (12) including a MOSFET (T). An integrated circuit (Y) monitors the cell voltage, and if the design voltage of the cell (S) is exceeded the circuit (Y) provides a signal to the gate of the MOSFET (T) so that part of the charging current (I) bypasses that cell (S), while most of the charging current flows through the cell (S). The bypass current flows only while each of the other cells in the battery are coming up to the design voltage, so that little power is dissipated in the bypass circuit (12). If the cells are balanced, so they accept charge equally, then the bypass circuit never carries current; if the cells are not balanced, they will be brought near to balance over a few charge/discharge cycles.