There needs to then be a hotkey to recharge/not recharge shields because sometimes you just want to blast through someone who has downed your shield, but you can't because the shields are recharging and you are unable to fire.In the image linked, it says you have 124,740 shield capacity, divide this number by 495 (the total capacity given per shield block) and you have 252 shield blocks on your ship.
Each shield block provides 5.5 regen per second (the game mechanic rounds this number down, so at the worst you'll only ever lose 0.5 regen from an odd number amount of shield blocks.)
This puts your total shield regen at 252X5.5=1386 which is what your image is displaying for your regen as well.
Each shield block charges 55 power per second to activate its regen, this means that to keep your shields active while under fire, you must generate 13,860 power per second.
Your stats say that your generating 43,558 power/second, with a total capacity of 53,263. This means that if your not running other systems (thrust, weapons, or various support systems) your ship should be able to maintain power on its shields indefinetly.