Here is a kool, low-cost & super easy to connect DC Multi-function meter (~$20.00)
...that seems perfect for electric go karts, mini bikes etc.
https://www.ebay.com/itm/DC-6-5-100...var=640851630118&_trksid=p2060353.m2749.l2649
Here are the specs:
A. Function
•1. electrical parameter measurement function (voltage, current, power, energy).
•2. The voltage alarm function (over voltage alarm thresholds, backlighting and voltage flicker tips).
•3. The power button clear function.
•4. Power-down data storage function.
•5. Large-screen LCD screen full display function (display voltage, current, power, energy).
•6. backlight.
B. display and key
I.Display Interface
•Display voltage, current, power, energy parameters from the large-screen LCD screen simultaneously.
II. Display Format
•1. Power: measurement range 0 ~ 2kW
• 1kW display format within 0.0 ~ 999.9W;
• From 1kW display format 1000 ~ 2000W.
•2. Power: measurement range 0 ~ 9999kWh
• 10kWh within the display format 0 ~ 9999Wh;
• Above 10kWh display format 10 ~ 9999kWh;
•3. Voltage: test range 6.5 ~ 100V
• Display Format 6.50 ~ 99.99V
•4. Current: Test Range 0 ~ 20A
• Display Format 0.00 to 20.00.
III. Button
1. The backlight control
• By short press the button to turn on or off the backlight, the backlight status automatic storage.
2. The power cleared
• Step 1: Press the button until the power area show "CLr" character, then release the button;
• Step 2: At this point in the power consumption flashing indicating the current status is cleared, if short press the button again, the
• consumption data is cleared and cleared quit flashing;
• Step 3: If no key is pressed within five seconds, it means that the power does not clear the data and exit cleared.
•3. The voltage alarm value
• Step 1: Press the button until the power area show "SET" character, then release the button;
• Step 2: After entering this state, the voltage of the high pressure area shows the current alarm value, the current area displays the current value of low pressure alarm,and the least significant bit starts flashing, then you can press the button through the +1 bit short, when there is no button operation When more than three seconds, the automatic adjustment of the position switch from high pressure to low pressure alarm alarm value has a value, a total of six, the scope voltage alarm threshold set for the 6.5 ~ 99.9V;
• Step 3: After setting, press the button until the display shows "PASS" character indicates the setting is successful and automatically exit the setting mode.
C. Notes
•1. This module is suitable for indoor, not outdoor
•2. applied load can not exceed the rated voltage and current.
•3. The wiring order can not be wrong.
•D. Specifications
•1. Working voltage: 6.5 ~ 100VDC
•2. Test voltage: 6.5 ~ 100VDC
•3. Rated power: 20A/50A/100A 2000W
•4. Measurement accuracy: 1.0
It can handle & read voltages from ~6VDC thru 100VDC
…& Amperages up to 100A
The back side is pretty much sealed up/enclosed
...the wiring diagram is right on the back
…& it's just a simple (4) wire connection (see pic below)
1. P- connects to the load side of the shunt
2. B- connects to the battery side of the shunt
3. B- connects to the negative (-) terminal of the battery pack
4. B+ connects to the positive (+) terminal of battery pack
It even has even screw down/clamp type wire connectors built in
...so, no soldering is required
It displays the Voltage (V)
...Voltage of the Battery pack
the Current (A)
...Amps being drawn from the battery
the Power (W)
...Wattage of the component drawing power?
Energy (Wh)
...battery pack capacity?
I have one installed on my Ariel Atom sized go Kart
…& it seems to work pretty good...so, far
...but, I'm still tryin' to digest all of, what it's telling us
Example:
When the Atom kart is first switched on (with a fully charged battery pack), the meter shows:
65.5V 0.04A
2.5W 665Wh
So, "to me" it looks like, the first figures "Voltage" 65.5V (upper left) show that the battery pack has 65.5V in it.
The second figures "Current" 0.04A (upper right) shows what Amps the speed controller is drawing (IIRC ~15mA) &/plus what Amps the meter itself is drawing too (must be ~24mA)
The third figures "Power" 2.6W (lower left) (I believe) shows the Wattage of the speed controller &/plus the meter too
The fourth figures "Energy" 665Wh (lower right) (I believe) shows the capacity of the battery pack in Watt Hours
Here is a video/"snippet" of this meter, on the Atom kart while in "high gear", going full speed (~35MPH).
https://www.youtube.com/watch?v=FSQ0qhfWa9g
* Observations:
1. Voltage drop ~4V? (that seems like a lot)
2. Amp draw ~70A? (but, the controller is labeled 35A)
3. Power ~4,000W? (& the motor is labeled 2,000W)
** Anymore info &/or explanations of what this meter is telling us
...&/or ways to put the info to use would be greatly appreciated.