SDC Series DC-DC Converters
Can the SDC-series dc-dc converter be used directly to charge batteries?
The SDC-series dc-dc converter cannot be directly used to charge batteries as the battery will feed back into SDC-series dc-dc converter if the input to SDC-series converter is removed or if there is no output from SDC-series dc-dc converter due to any reason.
This will damage SDC-series dc-dc converter. In addition, if the 12V battery is deeply discharged, it will send SDC-series converter into current limit for extended period of time and will lead to premature failure.
How can the SDC-series dc-dc converter be modified to work as a battery charger?
A Schottky diode (rated at 30 V, 30 A) in series with the positive output of SDC-series converter will eliminate feed back into SDC-series dc-dc converter. To compensate for the drop across the Schottky diode (0.4V to 0.5 V), the output voltage of SDC-series dc-dc converter should be increased to around 14V to provide a float voltage of 13.5 V for charging a 12 V battery (The output voltage of SDC-series converter can be adjusted using the internal output voltage control potentiometer (Call Tech Support for exact part reference).
Premature failure can also be avoided by reducing the current limit with the help of internal potentiometer (Call Tech Support for exact part reference).
How can the BBM-1225 be used in conjunction with the SDC-series converter to function as a battery charger and DC UPS?
If it is desired to use the SDC-series dc-dc converter for battery charging, the battery back-up module BBM-1225 could be used in conjunction with SDC-series dc-dc converter. The Battery Terminal of the output of BBM-1225 will provide a charging current of around 4 A.
The customer will have to adjust the output voltage of SDC-series dc-dc converter to 14 V as explained above when using BBM-1225. The customer will be able to power his 12 V load through the Load Terminal of the output of BBM-1225 up to the current rating of the respective SDC-series dc-dc converter less 4 amps.
