Alexfn":187bll24 said:
Monkey Mark":187bll24 said:
The battery is 18v, so it will be powerful enough . The 2ah rating refers only to how long between charges, not its actual power.
A tool with a 4ah battery will have more power than one running a 2ah. The 4ah battery will have 10 cells vs 5 in the 2ah so peak voltage is higher. Its a not a huge amount but its measurable.
A few videos on YouTube to demonstrate it
There are many things on YouTube. Evidence for breaking the laws of physics (and chemistry) will be hard to find though ;-).
The voltage of cells (a) varies with their state of charge, and (b) is determined by the cell design and their electrochemistry, NOT by their capacity.
With a larger capacity cell, you _might_ see a higher voltage for longer when the cell is fully charged, simply because it won't discharge so quickly, but overall, the voltage swing between fully charged and discharged will be exactly the same for any given number of cells and the same chemistry.
The 4Ah battery should NOT have twice as many cells, if it is supposed to work in the same system, otherwise it is a very poor design, and in the case of Lithium Ion, potentially dangerous. If it did, pairs of cells would have to be in parallel, which will knacker the weaker of the pair very fast, and have a propensity to explode on charge.*
It is far more likely to be the case that a 4Ah battery will either have physically bigger cells, or batch-selected ones that work better (or both).
I agree that you will probably see much better performance with the bigger batteries, but not for the reasons you suggest.
E.
*If they really do have twice as many cells, they can be made to work, but probably not for long (unless there is a very smart battery management circuit built in. And anyway, if that's the case they'd last longer but not be obviously more powerful.