... discharge 2.Cert.:CE,ISO,MSDS 6V 4ah rechargeable medical suctions battery for African Market Shenzhen Matrix battery Co.,Ltd is a professional ... caused by overcharging or misusage. Gas is released from the battery to return the pressure back to normal. (3)Container ... three months, to avoid irreversible sulfating. The battery should be changed when the battery jar broken or the electrolyte omitted, to ...