Can I increase voltage/mA by inserting a 1.5v battery in series into circuit?

Question

I have the following circuit, getting power from a serial port (RTS & GND) to activate a relay (SSR):

            1N4148

RTS-------|>|-----[ + SSR input - ]---------GND

As it is, I'm not getting enough current to activate the SSR, so I'm thinking about inserting a 1.5v battery like this:

            1N4148

RTS-----|>|-------| - 1.5v + |---------[ + SSR input - ]---------GND

Would this work? Would there be any problem with doing this?

Answer 1

Better to use a transistor to activate the relay.  I'd show you a schematic, but it's kinda hard to do it with a text editor.  Basically put the output to the RTS on the Base, the SSR input to the Emitter, and the battery to the Collector.  Ground it.