High frequency inverter type unit designed to both charge a battery and provide support for the battery during prolonged electronic diagnostic checks. Charge cycle has nine profiles designed to optimise the condition of the battery and the speed of the charge. Designed for use with vehicle batteries including VRLA (Lead Acid), GEL, AGM/EFB and Leisure on 12V and 24V systems. Temperature sensor allows accurate charging of battery, even when cold. Safety circuitry prevents sparks or polarity reversal. Once fully charged, battery may be left connected to be automatically conditioned and maintained.