4.0Ah vs 5.0Ah vs 8.0Ah
Same fit: these run the same tools
Lowest price we track at UK retailers, updated daily. We may earn a commission
They differ in 5 of 6 areas
Same tools, so this is about size, weight and cost. No overall winner: pick the size that suits the job.
EnergyThe 8.0Ah stores 100% more than the 4.0Ah: 144Wh vs 72Wh.
WeightThe 4.0Ah is the lightest at 0.6kg, the 8.0Ah the heaviest at 1kg.
PriceThe 4.0Ah is the cheapest of the three today, at £119.95.
Price per Ah8.0Ah £24.99, 4.0Ah £29.99, 5.0Ah £34.59.
Cells4.0Ah: 21700 tabless; 5.0Ah: 18650 cylindrical; 8.0Ah: 21700 tabless.
Good to know
Same toolsAll three fit every Festool 18V tool, and pair up on the Festool 18V Twin (36V) tools.
Same chargers201136 and 577019 charge all three. Charge times are in the specs below.
Energy
BP18TBX4
72Wh
BP18Li5.0
90Wh
BP18TBX8
144Wh
Maker figure, or volts × Ah where they don't publish one. Ah and Wh explained ›
Weight
BP18TBX4
0.6kg
BP18Li5.0
0.7kg
BP18TBX8
1kg
Price per Ah
BP18TBX4
£29.99
BP18Li5.0
£34.59
BP18TBX8
£24.99
Lowest price we track ÷ Ah. Full specs
BP18TBX4BP18Li5.0BP18TBX8
Voltage18V18V18V
Capacity4.0Ah5.0Ah8.0Ah
Energy72Wh90Wh144Wh
Weight0.6kg0.7kg1kg
Energy for its weight120Wh/kg (worked out)129Wh/kg (worked out)144Wh/kg (worked out)
ChemistryLi-ion (cylindrical)Li-ion (cylindrical)Li-ion (cylindrical)
Cell type21700 tabless18650 cylindrical21700 tabless
Fuel gaugeYesYesYes
Size (L × W × H)Not listedNot listedNot listed
Charge time, 201136, 57701932 min45 min1 hr 20 min
Lowest price£119.95£172.95£199.95
Specs from each maker's own documentation. "Not listed" means the maker doesn't publish it or we haven't found it yet; it never counts as a difference.
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