The Festool 18V 8.0Ah Tabless Battery Pack, TBX 8 (item number 579271) is the highest-capacity battery in Festool's 18V cordless system, built for tools that draw hard and run long — track saws, chop saws, and mobile dust extractors chief among them. This is an 18V lithium-ion battery pack designed for high-demand cordless tool use where runtime and sustained power matter more than compact size. It replaces Festool item number 577324, the previous BP 18 Li 8.0 HP-ASI battery, and while the capacity number stays the same at 8.0Ah, what's happening inside the pack has changed.

The core change with the TBX 8 is tabless cell construction, which replaces the previous High Power (HP-ASI) cell design used in the 577324. Tabless cells reduce internal resistance, which means less heat builds up while the battery is under load and more of that 8.0Ah of capacity actually reaches the tool as usable power instead of getting lost as heat. In practical terms, that's steadier output on a long cut and a battery that's ready to go back on the charger sooner because it never got hot enough in the first place to need a cooldown period. Festool also added a soft-touch base to this generation, which helps the pack grip the bench or a tool's charging dock instead of sliding around.

Everything else that made the 8.0Ah pack useful carries over unchanged: the 8.0Ah capacity itself, Bluetooth connectivity that auto-starts a paired CLEANTEC dust extractor when the tool switches on, AIRSTREAM active cooling for fast recharging, and the integrated LED display that shows charge level at a glance. None of that is new to this model — it's the tabless cells and the soft-touch base that separate the TBX 8 from the battery it replaces.

Charging is where the tabless design pays off most directly. Paired with Festool's SCA 16 rapid charger, AIRSTREAM's active cooling gets the pack back to a usable charge in as little as 25 minutes, which is fast enough to top off between cuts rather than swapping to a spare and waiting. The Bluetooth link goes beyond charge monitoring, too — pair it with a compatible CLEANTEC dust extractor and the extractor starts automatically as soon as the tool powers on, and the Festool app gives you charge level, temperature, and usage history without having to guess.

This battery is built for Festool's 18V tabless-compatible cordless tools generally, with one notable carve-out: it isn't intended for the ETSC 125, RTSC 400, DTSC 400, or CTC SYS, which are designed around a different, more compact battery format. For everything else in the 18V lineup — saws, drills, routers, and mobile extractors that benefit from maximum runtime — the TBX 8 is the pack to reach for.

Buy this if you're running long cuts, big sheets, or a mobile dust extractor off battery power and you're tired of swapping packs mid-task. If your tools are lighter-duty and a smaller battery already gets you through the day, the extra capacity and weight of the TBX 8 may be more than you need — but for saws and extractors that pull hard, this is the pack that keeps up.

The Battery to Grab When the Job Won't Quit

The Festool 18V 8.0Ah Tabless Battery Pack, TBX 8 is the pack you reach for when the tool you're running would otherwise be the thing slowing you down.

• Who it's for: Anyone running high-drain 18V tools — track saws, chop saws, mobile dust extractors — who's tired of a battery tapping out before the cut list does.
• Why it stands out: Tabless cell construction is the real story here — it's not a bigger battery, it's a better-built one that runs cooler and recharges faster than the pack it replaces.
• Worth knowing: It skips a handful of Festool tools that use a different battery format (ETSC 125, RTSC 400, DTSC 400, CTC SYS), so double-check fit if you're running one of those before you buy.

• What did this battery replace? It replaces Festool item number 577324, the BP 18 Li 8.0 HP-ASI. Capacity, Bluetooth® auto-start, AIRSTREAM charging, and the LED display all carry over — the new part is the tabless cell construction and a soft-touch base.
• How fast does it charge? As little as 25 minutes on an SCA 16 rapid charger, thanks to AIRSTREAM active cooling. Chargers are sold separately.
• Does it work with every Festool 18V tool? It fits nearly all 18V tabless-compatible tools, with the exception of the ETSC 125, RTSC 400, DTSC 400, and CTC SYS.
• Does it come with a charger? No. The SCA 16 Rapid Charger and TCL 6 DUO Rapid Charger are both compatible but sold separately.
• What's the warranty on this battery? Festool covers it under Festool Service, with free repair for the first three years, including battery packs and chargers.