This Solid State Constant Potential Battery Charger is capable of charging a large range of batteries, such as Vented Lead Acid, Sealed Lead Acid or Nickel Cadmium batteries. Extreme low RF interference makes this charger ideal for many applications. The electronic protection against reverse connection and short circuit allows the charger to be left in circuit during cranking, and to be operated in parallel with a charging alternator. This charger has two voltage sensing levels to give an alarm output should the output voltage move outside the set point limits. Local LED indication is provided and Battery Voltage Low and Battery Voltage High points can be adjusted with trim pots.