I'd say make them only one use, and then the module recharges based on the energy pips on systems.
Pretty much like the KERS in a Formula 1. Instead of being a consumable, the energy of the module must recharge itself first before the next use.
That way you can have virtually unlimited shield cell usages for long sessions without docking, so it is a buff in that sense. But it is also a nerf for single fights since they would take a long time to recharge while you are in combat. Also, make the module more demanding on your power plant, so people chose between offense and defense capabilities.
Pretty much like the KERS in a Formula 1. Instead of being a consumable, the energy of the module must recharge itself first before the next use.
That way you can have virtually unlimited shield cell usages for long sessions without docking, so it is a buff in that sense. But it is also a nerf for single fights since they would take a long time to recharge while you are in combat. Also, make the module more demanding on your power plant, so people chose between offense and defense capabilities.