Watt's Up Meter Question

[NitroVal]

I just got a Watt's Up meter so I can keep an eye on my new electronics setup. Only issue is I am running 8awg power wire from the batts to the ESC, but the wires on the Watts Up meter are only 14awg.
Im curious what would happen if I connected the meter between the ESC and motor? I am running 150a ESCs with 5S and am just not sure if it will be safe to run in line with between the batts and ESC. The meter handles 100A and up to 60V.

[befu]

No real knowledge

My guess would be no. The meter should be set up to read DC amperage and voltage.

The speed control is driving the three wires going to the motor, not the same thing.

ADD side note. Is a brushless motor basically the same as a 3 phase AC motor? It seems like it. Not brushes, swap any two power leads to reverse it. Why are they not a constant RPM motor then like a 480 motor? A 480 motor will spin at 1800 rpm and as you load it, it draws more current as it maintains it's rpm. I know the rpm is all based on the 60 Hz of our supply power.

Does a brushless behave the same at WOT? Just talking WOT, not taking into account a freek drive on a 460 for varying voltage/frequency.

Sorry about the ADD moment, but no, I would only put it in the battery side.

Brian (No real knowledge, but I know a couple of electrical engineers.....)

[sailr]

there is no meaningful way to use a watt meter on a boat. Unlike an airplane where you can restrain the plane while running up the throttle, if you did that on a boat, you would burn everything up.

Connect it to the motor? How you gonna do that. There's three wires on the motor and only two on the meter!

[NitroVal]

I dunno, I figure there were two power wires and a signal wire, but I honestly have no idea how a brushless motor works. This meter measures minimum peak, amp, voltage and milliamp usage, so you just run the boat like normal and it will show the highest reading when you bring it in

[Fluid]

It cannot be run on the motor side of the ESC. The Watt's meter records peak amp draw, but what most folks are interested in is the average draw. The problem is, peak draw is not representative of the average draw. I have datalogged peaks of over 300 amps, but the average was around 100. Recording the total mAh used is probably the best info the Watt's Up Meter and similar devices can give us - but we will know that information when we chage the pack. A true datalogger is far more useful.



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[sailr]

what brand meter are you using? I have several different ones and none of them retain peak readings, only give the reading at the moment.

[Steven Vaccaro]

Sounds like he's using this one.
http://www.offshoreelectrics.com/pro...?prod=dh-wu100
They have their place. I still use one for playing with batteries.

By the way you can "play" with a boat in the tub, just don't do it while the wife is around to see the mess it makes

[NitroVal]

Thats all I am really looking for is the peak amps, to make sure I am not running over the electronic's limits

[questtek]

Thats all I am really looking for is the peak amps, to make sure I am not running over the electronic's limits

Consider using an Eagle Tree V-3 data logging system. It gives you EXACTLY that including about a dozen more parameters. The attached pic shows how I use them in my tiny Carbon Fiber starships. Since I also use the GPS unit for speed, the top cowl is fiberglass rather than carbon fiber. I have gained a tremendous amount of info on the performance of these and other boats with this relatively inexpensive system. For example, just finding out that my ESC temps were over 200 F, I built better copper heat sinks and saved a pile of money on ESC replacements.

[sailr]

I have three different watt meters and NONE of them retain the peak readings. They only show you the data in real time.

what brand meter are you using? I have several different ones and none of them retain peak readings, only give the reading at the moment.