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HiltiWpg

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Posts posted by HiltiWpg

  2. So About Them New Batteries.

    in Milwaukee

    Posted

    cut the BS . current milwaukee 9ah battery uses lg HG2 18650 cells which is rated 20A discharge .

    they use 3 rows of cells , so thats 60A max discharge for current 9ah battery .

    cant argue with facts .

     

    i dont know what cells they use in the new line .

    but i know dewalt flexvolt uses Sanyo NCR20700A (not in the new 12ah)

     

     .which rated at 30A continuous discharge

    dewalt uses 10 cell batteries for flexvolt (until the new one comes out) , which gives also 60A continuous discharge . those are cureent gen batteries . new milwaukees and dewalts for sure have much higher discharge ratings (doh , they even called them like that)

     

     

    You may want to read a little further down.

    I wasn’t using a specific cell, which I should have, and i did. I was generalizing with an entry level cell/battery.

    I wasn’t talking about the Flexvolt initially which I should have, specifically.

    So I did.

     

     

     

     

    Sent from my iPhone using Tapatalk

     

  3. So About Them New Batteries.

    in Milwaukee

    Posted

    Let's take the flexvolt grinder. Under heavy use, it has a runtime of about 5 or 6 minutes with a 6ah battery (6ahx18v=108wh). Checkout Ave video if you don't believe me. 6 minutes = 10% of a hour. Therefore the grinder is consumming 108whx10=1080w.  To produce the same output with a 18v, you will need to push around 1080/18=60 A.

    Your math is wrong. 108wa would be the “optimal” discharge rate under “optimal” load. Overloading the motor or pushing it beyond its rated optimal discharge rate will most certainly drain it rapidly. As you push the battery, it heats up etc. There are variables at work that need to be accounted for. 

    You don’t consume watts. Watts are the rate at which energy is consumed. 

     

     

    Also, isn’t the Flexvolt grinder rated at 1700 watts at 54v? (31.5a)

    Those 20700 cells have a max discharge rate of 30-40a.

    3ah = 162wa @ 31.5a would be 5.1 minutes of runtime, roughly.

     

    If those same cells are present in the Milwaukee etc, the end result would be roughly the same.

     

     

    Sent from my iPhone using Tapatalk

     

     

     

     

     

  4. So About Them New Batteries.

    in Milwaukee

    Posted

    Your maths are off. Why 4 rows in parallel? The voltage and the number of rows are not linked together. The voltage is determined by the number of cells in series in a given row, not the number of rows. Each row has the same voltage but the more rows you had, the more current you can push. Therefore, you can add as much as you want to increase the amount of current your battery can push.

    Because they can use 4 rows? Maybe that’s why? It was an example.

    The math is sound. Regardless of 3 sets of series/parallel or 4, the manufacturers spec for the batteries is what matters.

    In series, your voltage adds up and your current remains the same, hence “3.6v x 5 = 18v”. The spec of the cell is 9.6a max, 4.3a optimal. In parallel current adds up and voltage remains the same. Each row is 4.3a, 4 rows parallel is 17.2a.

    Not sure how you didn’t get that.

     

    I should have used the High drain 20700 cells to be more specific with my example. The higher discharge rate would have simplified it.

     

    Sent from my iPhone using Tapatalk

     

  5. So About Them New Batteries.

    in Milwaukee

    Posted

    I am probably off a bit on the battery numbers, but close enough!

    Obviously no motor is 100% efficient and we don't know the PF, losses in the electronics etc, but I think the point is made.

     

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

     

     

     

    • Like 1

  6. So About Them New Batteries.

    in Milwaukee

    Posted

    A Samsung 21700 has a max discharge rate of 9.6A continuous, or something like that.
    With 4 parallel rows of cells, (each row is 3.6v x 5 = 18v 9A) that's 36A roughly of max current.
    For optimum life cycle, it is 1/2 of that, or 4.3 A continuous per cell or 16A using a 4 rows.

    18v x 16a = 288 watts or just under 1/2 Horsepower sustained load. Just about 1 HP peak.

    Sent from my Pixel 2 XL using Tapatalk

    • Like 1

  7. So About Them New Batteries.

    in Milwaukee

    Posted

    i have no time for online arguing . your house current rating has nothing to do with it .

     

    typical 15A corded tools (milwaukee claims they have same power as 15A corded) are 110V x 15 = 1650W 

    to reach the same power with 18V battery you need 1650/18 = 91A 

    so yes , to reach those power levels the batteries push near 100A , and even more for short periods . 

     

    your car jumper cables typically rated at 200a , car starter around 140A . they are much heavier gauge due to the length of the wire .

     

     

     

    Except that it has everything to do with it.  

    Cord connected tools don't run at 15a, first of all.

    Most tools are rated non-continuous which is a maxiumum 80% of 15A (max rating of circuit) or 12A. That's the max. The inrush current is typically 1.5x the continuous current.

     

    Typical household connected tools are well under 8A under load. The max inrush of current may spike to 12A etc, but any higher and your breaker may trip. This is why we have electrical standards.

     

    Cordless tools are not corded tools with a battery. Flexvolt could get close, but they are hybrid.

     

    Suggesting that a cordless power tool sustains 100-200 amps is ludicrous.

    For real though, the wire would need to be 1/0 ROFL!!!

    The tool would be massive and weight a ton!!!

     

    You can simply look up the manufacturers specifications on a battery cell and see what current is available and use ohms law to calculate the actual current capacity and maximum sustainable draw.

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

     

     

    • Like 1

  8. Ok, so what does Dewalt have up their sleeve ?

    in Dewalt

    Posted

    voltage may not be everything but higher voltage has the potential to perform better during high draw load?

    Voltage and current are directly proportional and current is inversely proportional to the load. Higher voltage = lower current, lower voltage = higher current.

     

    Having more "electrical pressure" reduces current requirement , which means less potential heat and smaller wire gauge etc.

    If they address heat issues etc, there is no reason these tools won't be competitive.

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

     

     

  9. So About Them New Batteries.

    in Milwaukee

    Posted

    i think they're making a mistake .

    they wanted to keep same battery platform , but the problem is , nobody gonna stick that huge 12A battery on an impact driver or a drill .and the new tools wont deliver full power with the old m18 batteries .

    so what was the point keeping the new batteries interchangeable ? 

    just to say its compatible ? 

     

    in my opinion they'll have no problem to keep up , power is still measured in watts , not in volts .but those ridiculously huge batteries wont be used on smaller tools anyways , so why bother keeping them at 18v .

     

     

    Except that flexvolt is already that big.

     

    The power delivery will be roughly the same.

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

    • Like 1
    • Haha 1

  10. So About Them New Batteries.

    in Milwaukee

    Posted

     

     

     

    even 18650 cells can output up to 60A peak currents .most of the time  top of the line cells not used in tool batteries though .

     

    the only problem i see is the stock milwaukee battery terminals . i dont see them being reliable for 100+ amps constant power .

     

     

     

    So much wrong with this.

     

    Firstly, there is no 100amp cordless tool.

    Your entire house is only 100-200amps.

     

    Second, it sure as hell isn't 60amps either.

    Your car's jumper cables would be smaller than the wiring inside that tool, if it existed.

     

    Your standard household receptacle is 15A, or 20A T-Slot.

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

    • Like 1

  11. So About Them New Batteries.

    in Milwaukee

    Posted

    I wonder if they did something like Metabo with their LiHD internals.  

    Metabo's approach:

     

    - Enlarged power rails and contacts capable of handling high currents

    - 3x better conductivity with cell connectors made of a specialized copper alloy

     

     

    Quoted from here: https://www.metabo.com/au/en/info/competence/battery-pack-technology/lihd-battery-pack-technology/

     

    Most people don't understand the relationship between voltage and current. DeWalt's marketing is proof of that. 

    18 volts and 60 volts can exactly do the same amount of work. Period.

    As long as the lower voltage batteries/tools can handle the current demand, there is no reason to worry about it, their engineers get paid to do that for us!

     

    While the 18V, high demand might be more expensive due to increased material costs for upsizing wires and electronics, the battery costs should be slightly cheaper and offset the tool costs. (Compared to 18v x2 or Flexvolt)

     

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

     

    • Like 2

  12. Better brushless 18v circular saw: DeWalt or Milwaukee?

    in Power Tools

    Posted

    In my experience over the past 25 years of building things, Milwaukee excels at circular saws and the Sawzall.


    You want the king of recip saws, go Milwaukee. 


    Anecdotal evidence and opinion aside, Milwaukee does make “good” cordless saws.

    They are hardly close to being the “king” of cordless recip saws.

    Recent reviews and testing put the 18x2 Makita Rear handle and Dewalt Flexvolt quite a bit ahead of the M18 Fuel offerings. That said, I am sure there is a newer Fuel coming out shortly.
    As for recip saws, the M18 Fuel is nowhere near top of the heap. In fairness to Milwaukee, their model is a little dated.



    Sent from my iPhone using Tapatalk

  19. Big event coming

    in Milwaukee

    Posted

    I think it's inevitable if fv can stick around, full hybrid table saw will stake out my further investment in the line. But the Makitas, holy shit lol picked up the drill+impact 2 batt kit when I went back to electrical from framing, and was sold immediately. Little ¼ inch impact snapped two ⅜ adapters, so I immediately sought out the dedicated impact. Recip will be next for certain, and I'm still regularly impressed with my dch273 so I'm on the fence about the rotohammer. Still, I'll be buying more blacked out Makita for sure.

    The recip is worth it. Excellent vibration dampening, size etc. It’s a little heavy, but not too heavy to prevent precise one-handed use.

    I always assumed that Flexvolt was going to be 120v. It made so much sense.
    They could literally take over every commercial job site. No power, no longer problem, slap in 2 batteries and go. No Batteries, plug it in.
    Table saws, chop saws, mitre saws, SDS Max.
    It would have been beautiful!


    Sent from my iPhone using Tapatalk
    • Like 1

  20. Big event coming

    in Milwaukee

    Posted

    I'm in love with my Makita sub compacts, just picked up the 3/8 impact yesterday, and I'm hungry for any other offerings in that vein regardless of color lol first non red or yellow (cordless) I've owned, and won't be the last.
    I bought the subcompact Drill, Impact, Recip and Rotary Hammer Drill.

    I.Love.Them.

    Working in tight/crawl spaces, on ladders and on lifts, I like the size and weight. I don't want a battery that weighs more than my current impact and battery combined! A flexvolt battery looks rediculous on a small tool.
    If they would have went full 120v AC or DC I think Flexvolt would have been perfect for big jobsite tools.

    Sent from my Pixel 2 XL using Tapatalk

  21. Better brushless 18v circular saw: DeWalt or Milwaukee?

    in Power Tools

    Posted

    Power is comparable. The Dewalt is certainly newer design and tech. Dewalt seems to own all things wood. I am not a Dewalt guy, but if I was looking for a new mitre saw, I wouldn’t think twice about buying a Dewalt. Milwaukee makes some great stuff, but the emphasis isn’t on saws. They make good ones, but they seem to be playing catch-up to Dewalt.
    Don’t buy Flexvolt because it has a bigger number. Buy it because Dewalt makes good saws. Don’t buy based on hype.

  22. Big event coming

    in Milwaukee

    Posted

    I’m no tech guy [mention=49609]Bremon[/mention] you know that. But they Must have something more then a 36v battery that works in all 18v existing tools and newer 36v tools ? That wouldn’t even match Flexvolt, and it’s kinda like 2x 18 Makita....which still doesn’t match up to Flexvolt....even 2x 36 wouldn’t power a 10” tablesaw,I think...

         it will be interesting to see for sure. If 1 thing I learned from you and the forum is don’t get your hopes up for a huge breakthrough show for any company especially Dewalt....I just lucked out that Flexvolt was my first experience with these shows, being new to the forum over a year ago...

         Double (2x36v ) Tools ? 

    You don't know how eletricimuty works huh?

     

    1/2 HP motor = 373 watts

    1 HP = 746 watts

     

    So let's play.

    373 watts @ 56 volts = 6a

    373 watts @ 36 volts = 10.3A

     

    See how that works? Lower voltage can do the same amount of work. Higher voltage = lower current, Higher current = Lower voltage. As long as the current is available, it can certainly do exactly the same work.

     

    Saying that you can't run a saw because it isn't a DeWalt fake 60volt is just wrong. It's ignorant.

     

    #ohmslaw

     

    Higher voltage is definitely better, lower current means smaller wire, lower heat etc. But you get the idea.

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

  24. upcoming grinder comparison - oztooltalk

    in Power Tools

    Posted

    Essentially the test will show the best power/run time you can get out of each of the grinders with the current battery options, but also if theres a power drop running regular (18650) batts (e.g. 5/6Ah)

    I think you need to do a grinder test, not a battery test. Get the WA as close as possible and let the grinders work it out. Having a 9AH vs a 5AH doesn't make sense. It may unfairly tip the scales in favor a tool that would perform the same or worse than another tool if it was tested with a lower capacity battery.

     

    Sent from my Pixel 2 XL using Tapatalk

     

     

     

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