An Arcane Batterist has become highly adept at creating and using arcane batteries, overcharging them to create volatile weapons or remotely activated explosive tools. Their ability to prepare a field for detonation, has made them popular as trappers; both in large scale warfare, but also urban skirmishes. Their use is however not limited to warfare, and often you will see them in the employ of big mining and demolishing operations, as well as members of exploration expeditions, where their unique skillset can ensure access to old ruins and walled in caves.

Changelog

• 2.0: Updated to allign with 2024 rules. Adjusted spell list to no longer have sleep, given the changes to that spell.
• 1.8.1: Simplified mechanic in Battery Expert to require only one d20 roll when the battery is thrown.
• 1.8: The Arcane Batterist now gets their second battery at level 8, to push up the signature move of exploding multiple spells at once. Still kept out of usual multiclassing range to avoid exploitation.
• 1.7.1: Fixed a bug in the "Create Arcane Battery" action.
• 1.7: Removed scaling of extra damage or healing based on gemstone value. 
  The values had to be low to make this balanced regardless of how much gold was available in a campaign. This made the gimmick more about bookkeeping than about choosing the right gem for the purpose.

Tool Proficiency

3rd-level Artillerist feature

You gain proficiency with glassblower’s tools. If you already have this proficiency, you gain proficiency with one other type of artisan’s tools of your choice.

Batterist Spells

3rd-level Arcane Batterist feature

You always have certain spells prepared after you reach particular levels in this class, as shown in the Arcane Batterist Spells table. These spells count as artificer spells for you, but they don’t count against the number of artificer spells you prepare.

Arcane Batterist Spells

Artificer Level	Spell
3rd	Thunderwave, Fog Cloud
5th	shatter, Spike Growth,
9th	fireball,  Magic Circle
13th	private sanctum, Ice Storm
17th	mass cure wounds, Teleportation Circle

Arcane Batteries

3rd-level Arcane Batterist feature

You've learned how to charge glass beads and gemstones to create arcane batteries. Using jeweler's tools or glassblower's tools, you can take an action to create an arcane battery containing a spell. Any spellslots used for the spell are consumed when the battery is crafted, and the spell inserted can not require concentration or have a cast time longer than one action.

As part of the action of creating the battery, or as a later action, the battery can be thrown as a ranged weapon with the properties Finesse, Thrown (range 40/80). It explosively discharges on impact. 

When a battery discharges, the bead or gemstone is consumed and the contained cantrip or spell is cast, using any creature hit as the center of the effect. For spells that work in a cone or line, the effect will always trigger in the direction furthest away from you. Any parameters of the spell, such as direction of the cast or the effect of the spell in cases where there are multiple possible, has to be determined when the battery is created. When a damaging or healing spell is discharged from a battery, you gain a bonus to one roll of the spell, determined by the quality of the battery:  

Glass bead (1 sp): 1d4 extra damage or healing
Gemstone (10 gp or more): 2d4 extra damage or healing

The damage die used increase to a d6 at level 5, to a d8 at level 11 and to a d10 at level 17.

You can only have one battery crafted at a time, this increases to two at level 8, and three at level 17. Batteries expire after a long rest. You can deactivate any battery you have created at will. You can give the battery for someone else to throw, but have to be within 400 feet of the battery for it to successfully discharge.

Prepared detonations

5th-level Arcane Batterist feature

You can now plant batteries and set them to trigger remotely, it is up to you whether this is by remote, by voice command or by a somatic gesture. The battery can be triggered in this way on a bonus action, using itself as the target of the effect, or in the case of line and cone effects, targeting as if the battery was thrown. You must be within 400 ft to explosively discharge the battery. If you have multiple batteries, they can be discharged by the same command or by different ones.

Amplified batteries

9th-level Arcane Batterist feature

Every Arcane Battery you create now has the capacity to expand the effects of spells cast through them.

• You can choose to increase the size of the area affected by a spell or cantrip to up to double the original radius in the case of a sphere or cylinder, or double the length and width in the case of a cone or cube. You have to decide range of the effect when creating the battery.
• You can choose to increase the duration of spells or cantrips cast through a battery to up to double the original duration.

Additionally, you can create sensors in your batteries, that cause them to trigger either on touch or movement within a proximity of 2 feet. You can choose to exclude tiny creatures from the sensors. Batteriescan now be triggered while you are up to 1000 feet away.

Battery expert

15th-level Artillerist feature

You’re a master at increasing the potency and effectiveness of your batteries, resulting in the following effects:

• Dexterity or constitution saving throws made to avoid or partially avoid the effects of a battery are now done with disadvantage.
• Your damage from arcane batteries ignore resistances.
• You can charge batteries at 120 feet range, provided there is already an empty battery in place.
• When exploding a gemstone battery, if the spell attack or ranged weapon attack roll is 18 or higher preserves the gemstone used. If the explosion requires no roll to hit, then roll a d20 just for the purpose of preserving the battery.