B&Q? Anyway, it’s as @Hughdg said, it’s the low ah rating that’s the issue, plus, IME, NiCad batteries don’t last as long as Lithium ones with regards to the number of times they can be charged. Would an 18v LXT 5ah battery pack fit in that tool of yours. The issue is the battery pack not the tool.
Nicad suffer from 'memory' exacerbated by not fully discharging before charging them, leaving them on a charger , using briefly then putting them back on the charger, fucks them in rapid time.... Typical examples: the early rechargeable screwdrivers, cordless vacuums etc
