The CH12R was a charging regulator for 12 V rechargeable batteries. It was commonly used when a rechargeable battery was required for the application and the PS12LA power supply did not contain enough reserve amp-hours for the power supply budget (see BP12, BP24 Battery Packs). The CH12R was connected to an external charging source such as a solar panel or wall charger.
The circuitry of the CH12R was similar to the PS12LA except a battery was not included. If the customer supplied the rechargeable battery, it had to be capable of accepting recharge from a trickle charge source.
