A idea to have Rechargeable shilds that arent the best but you can use batteries to rechage them. I know you can buy 2 shilds and just activace the other one.
And using batteries to super charge weapons
Say Sandhog +6 used 6 batteries to do X more amount of damage for that one shot.
Gas gernade that spits out laughing gas it does no damage but randomly changes the path of the shot onced fired. Say it will add 10-100 power or mess with the angle I think this has a use in slowing down sharpshooters. Its chemical warfare.