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  • #16
    Re: panasonic

    Are you kidding, they'd think is a laser blaster from the future :P

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    • #17
      Re: panasonic

      Hitachi looks like ****...

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      • #18
        Re: panasonic

        like S H I T !

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        • #19
          Re: panasonic

          The higher voltage is a huge advantage in terms of heat losses. I've noticed that the 36V tools heat up quite a bit less than 18V under heavy loading conditions. To the point where the 36 can seriously outpace the 18 for endurance. It's not just the increased power of the tools that's the advantage, it's the extra endurance as well.

          High current/low voltage is generally less preferred, as you say, because of the resistive losses. Same reason electrical companies go longer distances with high voltage lines, such as 500,000V. if they tried to transmit the same power at 120V, the resistive losses of the wires would just choke and ruin the efficiency of the whole thing.

          Originally posted by Disaster View Post
          It is definitely not a "one battery voltage fits all"
          kind of approach that will be the most successful. It is silly to have 24 volt batteries on a trimmer...or an impact driver for that matter. On the other hand I'll take 36 or even 48 volts on a circular saw if I can get it. A drill falls somewhere in the middle...18 volts is great for most purposes...perhaps supplemented by a heavy duty hammerdrill on the high end and a lightweight 14 volt cabinet makers drill on the other end.

          By the way, power is a combination of voltage and amperage. When going up in cells a tool can have less amperage and still get the job done. In fact, motors have a tendancy to run more efficiently at higher voltages. The automotive industry has been wanting to adapt high voltage systems (plus 36 volts) for years but have been hampered by the high initial cost and the safety concerns.

          What this means is a 36 volt cell 1.5 amp hour battery would have the same power as a 18 volt 3 amp hour battery. It would probably weigh slightly more, however, because it would require more individual cells.

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          • #20
            Re: panasonic

            Originally posted by Sceeter W Wheels View Post
            The higher voltage is a huge advantage in terms of heat losses. I've noticed that the 36V tools heat up quite a bit less than 18V under heavy loading conditions. To the point where the 36 can seriously outpace the 18 for endurance. It's not just the increased power of the tools that's the advantage, it's the extra endurance as well.

            High current/low voltage is generally less preferred, as you say, because of the resistive losses. Same reason electrical companies go longer distances with high voltage lines, such as 500,000V. if they tried to transmit the same power at 120V, the resistive losses of the wires would just choke and ruin the efficiency of the whole thing.
            The flip side to this is that while high voltage is more efficient...it is also more dangerous. "Current kills"...however voltage gives it the potential to kill.

            12 and even 24 volt systems are considered relatively safe. However, as you progress higher in voltage, the concerns grow regarding the potential to deliver a heart arresting current.

            http://home.scarlet.be/~be067749/58/

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            • #21
              Re: panasonic

              True, getting higher in voltage gives the ability to get shocked. I would say 36V isn't particularly high in that respect. Fortunately for cordless tools, it's completely isolated from ground. That's one problem with the power mains is that invariably you're standing on one of the conductors to one degree or another at all times. The only way you could get a shock with cordless is that literally you have both + and - of the battery touching you in such a way that you get the current through a critical part of your body such as your heart or brain. Chances of that happening? pretty slim.

              Originally posted by Disaster View Post
              The flip side to this is that while high voltage is more efficient...it is also more dangerous. "Current kills"...however voltage gives it the potential to kill.

              12 and even 24 volt systems are considered relatively safe. However, as you progress higher in voltage, the concerns grow regarding the potential to deliver a heart arresting current.

              http://home.scarlet.be/~be067749/58/

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              • #22
                Re: panasonic

                I think the range you can feel electric shock is somehwre in the 40 to 50v range, can't remember right now. 36v is already approching that level but I think its still way within the safe zone. I don't see much of a safety problem going to even higher battery voltages though. Tools have run off mains voltage for ever and that a lot more dangerous. At least with my cordless circular saw theres less of a chance of getting electrocuted after accidentally cutting the cord with a corded one

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                • #23
                  Re: panasonic

                  Originally posted by Sceeter W Wheels View Post
                  The only way you could get a shock with cordless is that literally you have both + and - of the battery touching you in such a way that you get the current through a critical part of your body such as your heart or brain. Chances of that happening? pretty slim.
                  Hmmm, wonder what would happen if I stick my tongue to the + and - terminals of my 18v batteries, they are side by side after all Probably not as easy to do on the 36v ones right?

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                  • #24
                    Re: panasonic

                    Originally posted by Velosapien View Post
                    I think the range you can feel electric shock is somehwre in the 40 to 50v range, can't remember right now. 36v is already approching that level but I think its still way within the safe zone. I don't see much of a safety problem going to even higher battery voltages though. Tools have run off mains voltage for ever and that a lot more dangerous. At least with my cordless circular saw theres less of a chance of getting electrocuted after accidentally cutting the cord with a corded one
                    True, especially because, as Sceeter mentioned, it is harder to actually get your hands "across" the DC power. It isn't likely that you would hold one hand on the battery positive and the other on the battery negative. :-) In the automotive industry it is a bigger concern because the whole body is grounded.

                    The bigger danger, in cordless electric tools is the fact that they always have power when the battery is attached. I less often carry a corded tool to the worksite with the cord attached. Also, I will usually unplug a corded tool if I'm walking away from it...a safety habit I developed over the years (being around curious children helped.) I'm not so good about unplugging batteries, however.

                    Ever bump the on switch and JUMP when it fires up!

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                    • #25
                      Re: panasonic

                      Velosapien - 18V across your tongue would hurt like a bit ch. tears are coming to my eyes just thinking about it.

                      Yup, the 36V battery terminals are very hard to stick your fingers or tongue into. Not that I've ever tried it It seems to be an advantage of the slider battery design that you can better protect the terminals. But they seemed to cover that aspect of the design pretty good.

                      Disaster - that's a great habit to develop, or to at least put the trigger lock on. you never know that your tool could fall and engage the trigger by getting caught on something. Something like a sawzall could really start flying around it started going full blast by itself!!

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