Doug Bock, group sales manager, Panasonic
Market may segment by price point and chemistry
The most meaningful advance in battery-operated power tool technology in recent years has been the introduction of lithium-ion batteries. Lithium-ion (Li-ion) offers several advances over the current battery chemistries of NiCad and NiMH.
The most significant is a reduction in weight. A tool utilizing lithium-ion batteries will typically weigh 25 percent less than the same tool using NiCad or NiMH batteries.
Another advance of lithium-ion is more capacity which delivers more run time per charge. The highest capacity lithium-ion battery currently is 3.0 Ah. This represents a 25 percent increase versus the highest capacity NiCad available at 2.4 Ah.
However, NiMH batteries offer a 3.5Ah capacity which means lithium-ion batteries will not necessarily deliver more run time than the highest capacity NiMH battery. Lithium-ion batteries have a more stable power delivery curve over the life of the charge than current battery chemistries, too. This means the power delivery will not deteriorate as the battery runs down, which is what typically happens with other batteries. And, Li-ion batteries will deliver more total performance over the life of the battery pack than current batteries.
At Panasonic we have found, through testing, that our lithium-ion batteries deliver at least twice the total lifetime performance versus our NiCad and NiMH batteries.
Slimming down
Yet, the most significant benefit of lithium-ion technology is a reduction in weight. It appears there are two schools of thought on how to utilize this new technology. The first group is utilizing the reduction in weight to build higher voltage tools (24-, 28-, 36-volt, for example) designed to deliver corded tool performance without the cord. With lithium- ion you can build higher voltage with less weight than in the past. The higher voltage tools are most practical for two-handed tools like a rotary hammer, recip saw or circular saw. However, they are less practical for the one-handed tools like a drill-driver, hammer drill and impact driver where the weight typically cannot exceed 6 pounds if the user is to work comfortably all day.
The second group is using the reduction in weight offered by lithium-ion to build tools in the traditional voltages (14.4- and 18-volt) that are more compact and lightweight than current models. At Panasonic we have always focused on building compact and lightweight tools. We are building 14.4-volt lithium-ion tools that weigh just a shade over 3 pounds but deliver 18-volt power and performance.
