Milwaukee 18V Battery Pack Innards . . .

Greetings,

Was walking through Home Depot yesterday and paused at this great Milwaukee Tools display. Wonderful stuff.

There was also a cutaway of one of their 18V battery packs. Here for your viewing . . .

Battery Pack Innard 1


Battery Pack Innard 2


That's it, just a little voyeuristic fun . . .

M.

You should have taken a photo of the thermistor that Milwaukee uses to monitor the battery during charge and use.

The Samsung cells being INR based are as safe as you're going to get.

I've got both the 3 Amp hr and 4 Amp hr packs. The only difference is that they use the 2500 mAh cells in the 4 Amp hr pack.

Would this be an 18V 4000mAh battery pack?

SubLGT said:

Would this be an 18V 4000mAh battery pack?

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Can't see the rest of the text on the battery, but new batteries in the 18 volt Red Lithium line are either 4 or recently 5 amp pack.

The 18v 2.8 and the 18v 4.0 packs look identical on the outside. Only difference is the cells used for the pack.

The 5 amp packs were released early this year but my distributor hasn't stocked any due to the price.

Very cool, thanks for photographing that.

So that brings up an interesting point. With 10 batteries that means two groups of five wired in series (5 x 3.7V=18.5V) and the two groups of five wired in parallel to double the amps?

magellan said:

Very cool, thanks for photographing that.

So that brings up an interesting point. With 10 batteries that means two groups of five wired in series (5 x 3.7V=18.5V) and the two groups of five wired in parallel to double the amps?

Click to expand...

Yep, that's correct. 5S2P.

My local lumber yard had a vendor day early this month. One vendor was pushing Makita for a extended flooring screw driver. I asked how much torque the drill had and was told it was the highest on the market. Somewhat stumped I asked if they had tested the Milwaukee brushless drill, which I suspected.

Long story short, the Makita didn't have the torque to ring off some of their screws while the Milwaukee busted off five in a row.

Wow. Very impressive!

Wonder what accounts for the difference in torque? I'd be curious to know if it's in the motor, the gearing, or the batteries.

magellan said:

Wow. Very impressive!

Wonder what accounts for the difference in torque? I'd be curious to know if it's in the motor, the gearing, or the batteries.

Click to expand...

I suspect that the combination of the motor and the gearing account for the higher torque. The batteries and the brushless motor account for increased run time.

Makes sense, thanks!

...brushless DC motor...hadn't thought about those in a while since I play with flashlights more than powered hand tools at this point in my life, but if I remember right (the ol' memory ain't what it used to be, so please feel free to correct if I get anything wrong) they are distinguished by the fact that they develop a rectangular or trapezoidal back EMF rather than the typical sinusoidal back EMF of an AC synchronous motor. Other than that a brushless DC motor is very similar to a synchronous AC motor.

The price of tool battery packs is crazy.

A Bosch 18V Li-Ion 4Ah is $99. There is also a 5Ah and 6Ah version, but I was afraid to check the prices on those.

A Milwaukee 18V NiCd 2.4Ah pack is $99.

It is often cheaper to wait for a sale on a tool/battery/charger combo, or charger/battery combo, and buy the combo just to get the battery!

Your not comparing apples to apples.

Milwaukee no longer makes tools using the NiCad battery pack. I only have one item, a Jobsite radio that uses this battery. Great sounding radio due to the Fosgate amp inside. Other than some of the guys that build aftermarket batteries, you don't have much choice.

I know a lot of folks don't like eBay, but all of the major tool batteries can be found there at big discounts.

I personally haven't seen a Bosch battery in a 6Ah version, only the 3 or 4's, and recently 5Ah.