Shield cells and chaffs are by far the most useful defensive armaments for combat.
Shield cells: the only thing that matters is how many charges it carries. Check out the wiki for it (it's not straight forward for x# and # of charges). The AMOUNT healed is the same for all types - they'll regen your shields to full (well, maybe not all the way if you are still getting pounded while you use a shield cell charge). You can even have two on at a time (you have to manually turn multiple banks on and off, because all active banks are used at the same time when you use the shield cell hot key), which allows you to extend the amount of time you are fighting. Hit it when you FIRST drop to the single blue shield circle (because if you are down to it, someone is pounding you hard, don't wait any longer). Does NOT work if your shields are already depleted.
Chaff: I use this as a buffer if I know I'm getting shot at from med/long distance. Not as useful if I'm really close to my enemy. It jams gimballed/turreted weapons (which most NPCs and PCs seem to carry). There are a lot more chaff ammo than cell banks, so I try to use chaff as often as needed (under fire) so I don't have to use banks as much.
As advanced techniques, I try to switch pips from weapons to shields as much as I can when I'm getting shot at / maneuvering and not shooting. Because more pips in shields does strengthen the shields you already have (but shield pips do NOT increase the rate at which they regenerate).
Shield cells: the only thing that matters is how many charges it carries. Check out the wiki for it (it's not straight forward for x# and # of charges). The AMOUNT healed is the same for all types - they'll regen your shields to full (well, maybe not all the way if you are still getting pounded while you use a shield cell charge). You can even have two on at a time (you have to manually turn multiple banks on and off, because all active banks are used at the same time when you use the shield cell hot key), which allows you to extend the amount of time you are fighting. Hit it when you FIRST drop to the single blue shield circle (because if you are down to it, someone is pounding you hard, don't wait any longer). Does NOT work if your shields are already depleted.
Chaff: I use this as a buffer if I know I'm getting shot at from med/long distance. Not as useful if I'm really close to my enemy. It jams gimballed/turreted weapons (which most NPCs and PCs seem to carry). There are a lot more chaff ammo than cell banks, so I try to use chaff as often as needed (under fire) so I don't have to use banks as much.
As advanced techniques, I try to switch pips from weapons to shields as much as I can when I'm getting shot at / maneuvering and not shooting. Because more pips in shields does strengthen the shields you already have (but shield pips do NOT increase the rate at which they regenerate).