Combat
The Last Caretaker Backpacks: Every ONi Battery and Petrol Backpack Compared
The Last Caretaker has six backpacks, all ONi models. SparkCell, VoltPlus and MegaCell store electricity; FuelLite, PetroFlow and PetroMax store petrol. They unlock from Tier 5 to Tier 16 and weigh 5 to 10 kg. Update 6 adds a new backpack for carrying items on your back.
Unlock tiers, weights and recipes are cross-checked (B): the community wiki matches the game 0.8.5 item data (September 15, 2026 build). Capacities have only one source so far and are kept separate below.
All Six Backpacks Compared
Within each type, a later backpack unlocks at a higher tier, weighs more and needs more advanced parts. Plan the unlocks in the Skill Planner.
| Backpack | Stores | Unlock tier | Weight | Recipe | Capacity |
|---|---|---|---|---|---|
| ONi SparkCell | Electricity | Tier 5 | 5 kg |
| Not cross-checked |
| ONi VoltPlus | Electricity | Tier 11 | 7.5 kg |
| Not cross-checked |
| ONi MegaCell | Electricity | Tier 15 | 10 kg |
| Not cross-checked |
| ONi FuelLite | Petrol | Tier 7 | 5 kg |
| Not cross-checked |
| ONi PetroFlow | Petrol | Tier 10 | 7.5 kg |
| Not cross-checked |
| ONi PetroMax | Petrol | Tier 16 | 10 kg |
| Not cross-checked |
Cross-checked (B), reviewed 2026-10-11. Each row matches a wiki revision against the game 0.8.5 item data; where they disagree, both values are shown.
Which Backpack for Which Weapon
Electric weapons do not take ammunition: with the weapon held, press F to pull out its cable and connect it to a power source such as a deck supply or a powered backpack. Flame weapons refill petrol through their hose, and a recorded refill connects one to a petrol backpack. So a battery backpack (ONi SparkCell, ONi VoltPlus, ONi MegaCell) keeps electric weapons charged, and a petrol backpack (ONi FuelLite, ONi PetroFlow, ONi PetroMax) keeps flame weapons fueled.
Cross-checked (B). Videos and wiki recorded before Update 5.5. Details in the combat guide: how to charge and refuel weapons.
Sources: Community wiki: Weapons · Trustee Nonebar Gaming, January 11, 2026, at 5:30: backpack connected to an electric weapon · Great Taz Gaming, January 29, 2026, at 4:35: petrol refill · Steam discussion: electric weapon charging, January 2026
Capacities: Player reports, not yet verified (C)
The community wiki is the only source for capacities so far, and it gives two different figures for SparkCell. These numbers are not used in any calculator on this site.
- ONi SparkCell
- 200 Wh on the wiki's backpack list, 250 Wh on its SparkCell page
- ONi VoltPlus
- 500 Wh
- ONi MegaCell
- 1,000 Wh
- ONi FuelLite
- 100 L
- ONi PetroFlow
- 200 L
- ONi PetroMax
- 400 L
Sources: Community wiki: Backpacks (revision 5931) · Community wiki: ONi SparkCell (revision 7265)
The New Update 6 Backpack
Channel37's October 1 preview for Update 6 shows a new backpack that lets you attach items to your back, such as a large barrel, and climb ladders while carrying one.
The preview does not show its capacity or recipe. Update 6 has been in public beta since October 9, 2026; the full update has no date yet.
Official (A). Official X preview video, October 1, 2026, and the Update 6 public beta post. See everything Update 6 adds on the update tracker.
Sources: Official X preview video: backpack (October 1, 2026) · Official Steam post: Update 6 public beta (October 9, 2026)
Backpack FAQ
What is the best backpack in The Last Caretaker?
It depends on what you carry. SparkCell, VoltPlus and MegaCell store electricity for electric weapons; FuelLite, PetroFlow and PetroMax store petrol for flame weapons. Each later backpack unlocks at a higher tier and weighs more, from 5 kg to 10 kg. Their capacities have not been cross-checked yet, so we do not rank them.
How many backpacks are there?
Six, all ONi models: three store electricity and three store petrol. The community wiki and the game 0.8.5 item data list the same six.
Is there a diesel backpack?
No. The six backpacks store either electricity or petrol. The fuel backpacks, FuelLite, PetroFlow and PetroMax, hold petrol.
How do I charge an electric weapon from a backpack?
Hold the weapon, press F to pull out its cable and connect it to a powered backpack or another power source, such as a deck supply. The weapon's rear display shows its charge from 000 to 100.
How do I get my first backpack?
Craft it. ONi SparkCell is the first, unlocked at Tier 5, and is made from a Battery Cell, an Alloy Frame and Connector Ports. The first petrol backpack, ONi FuelLite, unlocks at Tier 7.
What is the new Update 6 backpack?
In Channel37's October 1 preview for Update 6, a new backpack lets you attach items to your back, such as a large barrel, and climb ladders while carrying one. Channel37 has not shown its capacity or recipe.
All sources
- Community wiki: Backpacks (revision 5931)
- Community wiki: ONi SparkCell (revision 7265)
- Community wiki: ONi VoltPlus (revision 7266)
- Community wiki: ONi MegaCell (revision 7264)
- Community wiki: ONi FuelLite (revision 6969)
- Community wiki: ONi PetroFlow (revision 6970)
- Community wiki: ONi PetroMax (revision 6971)
- thelastcaretaker.ru: game 0.8.5 item list
- thelastcaretaker.ru: ONi SparkCell (game 0.8.5)
- thelastcaretaker.ru: ONi VoltPlus (game 0.8.5)
- thelastcaretaker.ru: ONi MegaCell (game 0.8.5)
- thelastcaretaker.ru: ONi FuelLite (game 0.8.5)
- thelastcaretaker.ru: ONi PetroFlow (game 0.8.5)
- thelastcaretaker.ru: ONi PetroMax (game 0.8.5)
- Community wiki: Weapons
- Trustee Nonebar Gaming, January 11, 2026, at 5:30: backpack connected to an electric weapon
- Great Taz Gaming, January 29, 2026, at 4:35: petrol refill
- Steam discussion: electric weapon charging, January 2026
- Official X preview video: backpack (October 1, 2026)
- Official Steam post: Update 6 public beta (October 9, 2026)
