Accel charges can be useful as they decrease the time to charge a Beam and the power bomb so can E-Recovery tanks in restoring energy. You can refer to the guide below to find the locations of all the available Accel Charges in Metroid Other M.
Metroid Other M Accel Charges Location Guide
Accel Charge 1 (Sector 1)
Head to the area south of the monstrous trees and enter the restroom. Accel charge is placed in one of the stalls.
Accel Charge 2 (Sector 3)
When you are about to leave the room, you will see three circles at the floor. One of them is the path towards the Accel charge. You will find a morph ball launcher behind one of them. Enter it and you will ultimately head toward the charge located in the room.
Accel Charge 3 (Sector 2)
Once you have defeated the wooden villain in the snowy area, a spot on the map will appear on the upper level. Use your first person view to destroy the icy structure to have your Accel charge.
Accel Charge 4 (Main Sector)
There is a large room with Zoomer infestation. Destroy the locked portion containing the charge. You can use your beam to do that.
Accel Charge 5 (Sector 3)
There is a hidden room in thermal power plant where you fought with Ridley near the Missile tank. Use the grapple point to reach it and have the charge.
Accel Charge 6 (Sector 3)
Over the massive lava pool (northwestern region), there is a glass tube. To the east of it is a room, you need to destroy it to get the charge.
Metroid Other M Energy Recovery Tanks Location Guide
E-Recovery Tanks allow you to recover an additional Energy Tank on using concentration to recover energy.
E-Recovery Tank 1 (Sector 2)
From the water tank, head north. You need to get through a wall to get to the tank. To break the wall, run an appropriate long distance before reaching the barrier.
E-Recovery Tank 2 (Sector 2)
In the gravity area, you need to space jump to get the tank at the corner. Obviously you will be requiring your gravity suit here.
E-Recovery Tank 3 (Sector 1)
Near the Biosphere portion and the exam center, you need to locate a room having a power bomb door. Open it to have the tank. Beware of the soldier inside it.