Eletronic Meters - Current & AMP Draw

[adriantan]

Looking for electronic meters that will report things like min. / max. current draw, amps, mah used, & etc.

Need to find out whether my battery, motor, esc, gearbox & prop combinations match and whether I am pulling too many or too little Cs.

What are you guys using ? and which is the best one out ther that you recommend that is value for money? 

[shutay]

I recently bought a Feigao (Fat Dog?!??) Power Analyser. Typically, like most of these devices, it sits between the battery and the battery input socket in the ESC. It comes with a serial cable that plugs into the unit and into your PC. Bought it a few days ago, haven't tested it all out yet since I've got a few adapters to make, bullet connectors to solder up before I can make use of it. Gimme a call and we can test run it together.

[adriantan]

"Watt's Up" RC Watt Meter seems pretty cool. Just found it on the internet. Do all meters show more or less the same things? How is the Fei Gao as compared?

Features

• Measures EIGHT values including: energy (Wh), charge (Ah), power (W), current (A) and voltage (V)
• Captures peak current (A),peak power (W) and minimum voltage (V) (sags)
• Minimum voltage capture makes it easy to setup the cutoff voltage on your speed control, see the effect a prop or motor change has on your battery voltage or detect a stalled servo, bad battery and more
• Peak Amps and peak Watts capture shows you the maximum current and consequent power (instantaneous voltage X peak current) drawn and even if they only happen for a fraction of a second. Too fast to see any other way.
• Measurement down to 0 V when using an auxiliary (e.g. receiver) 4 - 60 V battery or other DC power source
• Small & Light: 2.8" L x 1.7" W x 0.83" D (70 mm x 44 mm x 21 mm), 2.3 oz. (1.7 oz. without case).
• Sharp, high contrast, readable in sunlight, LCD display
• Accurate & Hi-resolution - better than 1% typical accuracy. 0.01 A current and 0.01 V voltage resolutions. Great for cell balancing
• Rugged - can handle 50 A continuously and 100 Amps peak (for typical flight test duration) at 60 V
• 3.8" long, 14 ga., 7 x 37 stranded, high temp silicone rubber insulated wire. Supplied without connectors
• Acts like a wire so doesn't affect model's performance. Precision current sensing resistor, with only 0.001 Ohm resistance and circuitry only draws 0.007 Amps
  Uses DSP to increase ADC resolution and differential measurement amplifiers to increase noise immunity
• Factory calibration stores constants in EEPROM to compensate for component tolerances
• Powerful, 8 MIPS micro-controller
• One Year Warranty
• Complete User Manual
• Quality made in USA to ISO 9001 (like Hewlett Packard uses) quality standards
• Comes in cool colors.  (pop-up window, takes a moment to load)

Specifications

• Voltage 0-60 V with 0.01 V resolution. ± (1% + 0.035) Worst case accuracy. 60 V is a 14 cell series li-poly pack!
• Current 0-100 A peak, 50 A continuous, with 0.01 A resolution. ± (2% + 0.06) Worst case accuracy.
• Charge 0-65 Ah, resolution 0.001 Ah. That's ~32 Amps for two hours!
• Power 0-6554 W, resolution 0.1 W. That's ~8.7 Horsepower!
• Energy 0-6554 Wh, resolution 0.1 Wh. That's lifting a 50 pound model into outer space (65 mi.)!
• Operates from 4.0-60 V and 0 V with auxiliary 4 - 60 V battery pack (e.g. receiver pack)
• 16 character x 2 row STN LCD digital display
• Auxiliary power connector Uses a standard male "servo" type connector like found on receiver battery packs. JR / Hitec and Futaba are acceptable. Airtronics are wired backwards! Positive voltage should be on red/orange lead, minus voltage on black/brown lead.
• Auxiliary power input works with ANY 4.0 to 60 Volt DC input that can supply at least 7 mA.

[shutay]

Here's the link to the Feigao website with photos of the device itself and what little write up they have about it.

http://www.feigao.com/sdp/85838/4/pd-102732/1533218-51426.html

In true China tradition, I don't really understand what half the write up is saying, but here's their spec sheet:

Product Description
1. Following shows the 5 parameters for product's basic characteristic.
Voltage measuring: 5-36V (version 2)
Current measuring: 0-100A
Maximum input Power:0-3600W
Amp-hours: 0-999.9AH
Watt-hours: 0-999.9WH
2. Automatically adjustment, adjustment procedure unnecessary.
3. Automatically exchanged between high & low current.
4. Automatically exchanged between high & low voltage.
5. PC supported PowerView software, including monitoring & drawing function

Clearly, it captures the same 5 fundamental values and (at the moment), I presume the other metrics can be derived from these 5 measurements. It certainly doesn't seem as all singing and dancing as the Watt's Up meter, but does it do what it's meant to do? I hope so and we'll find out soon.