There are many uses to satchel charges, some being tactical, some being for fun. Satchel charges can be used:

1- To blow up bridges, especially on maps where bridges are the only way for land-only vehicles to cross water gaps. Be careful though, not all bridges can be blown up, especially not the ones with more complex structures.

Usually one charge is enough to blow the bridge enough to prevent a vehicle to cross it, use two if you need to blow up the majority of the bridge.

2- To blow up enemy vehicles. From a tactical point of view this would be to hinder enemy troops from mobilizing, especially on large maps or maps where some vehicles are scarce and vital. (AS-Twin Island, AS-Black Rock Beach and so on). Aim for the least available vehicles, usually being LCACs and APCs as well as Chinooks/Halos.

>From a "fun" point of view, you can trap their vehicles, but instead of blowing it up straightaway, wait for it to be full of enemies, and then detonate the charge. You can also trap your own vehicles, wait until it is near the enemy base and then blow it up. Be careful not to get your teammates killed though, wait for them to leave the vehicle.

NOTE: On large vehicles, more than one charge might be needed.

3- To defend a bunker. When enemies are attacking a bunker and all hope to keep it seems lost, booby-trap the interior, either near turrets or behind the armory. Be careful not to get killed though, as you would lose your charges. Also, you can place them before enemies arrive, but again, be careful that Friendly-Fire isn't turned on, as blowing up the charges could kill your teammates and wipe out the defence.

4- To attack a bunker. When enemies are away, trap the bunker in the same way to defend it, but instead of going inside and placing them, pop them through the windows (crawl to the base, then kneel to throw it in and then crawl to safety again). If your lucky, you should be able to detonate the charge before anyone sees it.

Also, when flying in a helicopter, have the pilot hover a few seconds above an enemy base so that you can drop both onto them, then fly to safety. You'll have to wait before you can efficiently blow them up, as they have to fall to the ground first and that can take various amounts of time depending on the height at which they were thrown.

There are other ways of using satchel charges, but not all are listed. When using these, always be careful to be a good distance away before detonation, as they have an effective blast radius of about 30m! Also, to make the explosion more powerful, you can detonate the charge with a frag grenade.