The only way a C02 shifter smacks harder is with more C02 pressure. 110-120 psi ought to do it. I supply 16V to activate the solenoid. I don't leave 16V on it then supply ground to activate. I've never had any problem with dual 16V batteries and no alt. with any electric component. I've been involved with some S/C dragsters that had accumulators on them with 16V and no problem ever with them.