Sealed de-ionized water producing system automatically monitors and controls water output. Ions are constantly regenerated to keep the water electric resistance above 500 kilo ohms, ensuring very low level of self discharge rate inside batteries. FULLRIVER has created a unique electrolyte formula formulated by adding special sub-colloids to pure concentrated sulfuric acid. This special electrolyte, used in our HL and HGXL series, results in higher reliability and longer life of our products.