Source: https://www.saftbatteries.es/download_file/6X7JMGAnv3Fm6HdmtEv%2B2gtlbZ1bRRVHkjS11M6md92GD2EF7vU%2F3Oybbz3WOlG%2BxR8srpA5iCdJ%2FV3IQzTVHQyiTucngZKEg9KkYCLkowAvgaG1huq2kyLwehSjTOwPmh1%2BhZWiDzTQL7uKjaY6XtEPoBWu64HeqdWBz07ZePZRYC3h7A%3D%3D/Cell+topping+up+for+NiCd+DC_Product+datasheet_EN_0417_LR.pdf