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Discussion Starter #1 (Edited)
Hello everyone!
We've just released PowerWatcher 3.0 Yay:)!
This device collects various data from your electric transportation device and displays it on your Android smartphone.
You can control the energy consumption of the battery in different modes of movement, receive a lot of useful information in real-time such as:

- Amper/Hours Spent | Total Amper/Hours
- Watt/Hours Spent | Total Watt/Hours
- Amper/Hour Recuperation | Watt/Hour Recuperation
- Charge Level
- Cycle Count
- Min Voltage | Max Voltage
- Max Current
- Max Speed | Average Speed
- Temperature
- Distance

What's new in PowerWatcher 3.0:
- The device now has a new, more compact design.
- Increased power voltage (5 volts). This allows charging your phone from the device when it's on.
- Added RS485 bus support. Now you can extend the device functions using the external sensors.
- Optocoupler is used for the speed sensor.
- The device comes in two variants depending on supply voltage.

You can find more detailed info about the device on our website: https://powerwatcher.net/

Pricing:
- PowerWatcher 3.0 High Voltage Kit: $83.90
- PowerWatcher 3.0 Middle Voltage Kit: $67.53

The Kit includes the following items:
- PowerWatcher3
- Bluetooth adapter
- 2 thermal sensors
- RS485 Voltage Sensor
- RS485 Current Sensor
- Wires

Differences between High Voltage Kit (HVK) and Middle Voltage Kit (MVK):
1. HVK measures voltage using an external voltage sensor, which can measure up to 600 V. MVK measures voltage using an internal sensor.
2. HVK supply voltage is from 12 to 30 V. MVK - from 30 to 200 V.
3. HVK uses a digital current sensor (RS485). MVK uses analog current sensor.

You can order the device in our shop: https://shop.emkit.net/shop/category/powerwatcher3-1

If you have any questions, please reach out in the comments below. We'd like to hear from you.

Here are some photos of the device and the Android screens:


naked_powerwatcher.png
screen1.png
screen2.png


Also, you can see it in action here:
https://youtu.be/Xv0pa3uMPN0
https://youtu.be/OWRqpA9aVyI
 

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Can the user tweak the CEF or is that automatically calculated only?

Is Peukert coefficient adjustable?

Can the 100% Full point be reset manually? Can it be alternatively set to trigger based on a trailing endAmps setpoint?

Please consider releasing a version for monitoring banks not involved in propulsion.
 

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Discussion Starter #4 (Edited)
Can the user tweak the CEF or is that automatically calculated only?

Is Peukert coefficient adjustable?

Can the 100% Full point be reset manually? Can it be alternatively set to trigger based on a trailing endAmps setpoint?

Please consider releasing a version for monitoring banks not involved in propulsion.

The Peukert coefficient is not adjustable. For lithium batteries, the Peukert coefficient is 1. And the amount of Amper/Hours for the battery is set in the settings.
Can you elaborate on your other questions? I'm not sure I get what you ask.
 

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Discussion Starter #6
Hello
Do not you have a current sensor for more amps?
450 amps are not much.
Nice dashboard.
Greetings Boxster-warp

Hello Boxster-warp,
We have a sensor like that, but it has a lot of factors affecting its readings. Here are some of them:
- The shape of the conductor on which this sensor is installed. If we install it on a round wire, it has one amplification coefficient. For the square wire, it will be completely different. etc.
- The position to the horizon (it catches the magnetic field of the Earth).
So, if you're fine with the slight measurement errors like that, then you can order it here: https://shop.emkit.net/shop/product/current-sensor-pw-ss49e-2

Or, alternatively, we can make the version without the ring installed. You can indicate this when you decide to buy it.
 

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Can you elaborate on your other questions? I'm not sure I get what you ask.
> Please consider releasing a version for monitoring banks not involved in propulsion.

There are a lot of use cases for using LI batteries for purposes other than for just proplusion, EVs ebikes etc.

Such a battery monitor version would eliminate miles traveled for example.


> Can the 100% Full point be reset manually?

SoC% is not going to be accurate unless the top 100% point is reset / calibrated frequently.


> Can it be alternatively set to trigger based on a trailing endAmps setpoint?

Say my 100% trigger is:

4.15V, trailing amps drops to 0.03C


> Can the user tweak the CEF or is that automatically calculated only?

Charge Efficiency is the ratio of input amps to put output amps back.

So, in a PSOC scenario, not getting back to 100%, if I take 70Ah out, I might need to put 75% back in to reach that same SoC%. CEF is thus 1.07

Some BMs automatically calculate this, but then let the user override manually.

Peukert should be adjustable, LI batteries can vary between the different chemistries, even 1.04 will affect SoC% accuracy over time.
 

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Hello
Really a nice dashboard and the price is great.
From how many volts does the high voltage version start?
First step my conversion with 170v and Second step a year later 216v.

Greetings Boxster-Warp
 

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Discussion Starter #10 (Edited)
Hello
Really a nice dashboard and the price is great.
From how many volts does the high voltage version start?
First step my conversion with 170v and Second step a year later 216v.

Greetings Boxster-Warp
Differences between High Voltage Kit (HVK) and Middle Voltage Kit (MVK):
1. HVK measures voltage using an external voltage sensor, which can measure up to 600 V. MVK measures voltage using an internal sensor.
2. HVK supply voltage is from 12 to 30 V. MVK - from 30 to 200 V.
3. HVK uses a digital current sensor (RS485). MVK uses analog current sensor.

In your case will be a good HVK.
 

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Discussion Starter #11
Yuriy, What is high voltage? 400V?

Differences between High Voltage Kit (HVK) and Middle Voltage Kit (MVK):
1. HVK measures voltage using an external voltage sensor, which can measure up to 600 V. MVK measures voltage using an internal sensor.
2. HVK supply voltage is from 12 to 30 V. MVK - from 30 to 200 V.
3. HVK uses a digital current sensor (RS485). MVK uses analog current sensor.
 

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Also is it possible to communicate the values measured to other monitoring gear, perhaps use them to trigger contactors open/closing, for OCP, HVC/LVC, overtemp?
 

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What kind of display can we connect to it besides Android?
What i mean is, if one would like to have a small 1.8" OLED display to show % SOC and Voltage, could you accomodate this? Or maybe bigger displays?

tnx
 

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Android platform is pretty much all based on open source, including tiny wearables, so only limited by skillz and imagination.
 

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Discussion Starter #16
What does recuperation mean, regen?

How many powerwatchers can I switch between per phone/tablet?

Yes, recuperation basically means regen.
At the moment the software doesn't allow to connect multiple devices simultaneously. You'll need to pair/unpair each device individually. Something to work on for the future versions:).
 

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Discussion Starter #17
> Please consider releasing a version for monitoring banks not involved in propulsion.

There are a lot of use cases for using LI batteries for purposes other than for just proplusion, EVs ebikes etc.

Such a battery monitor version would eliminate miles traveled for example.

You can use PW not only on EV. The first display can be tuned by the user. In a horizontal layout, only gauges and battery can't be tuned. In vertical can be tuned all display places.

> Can the 100% Full point be reset manually?
SoC% is not going to be accurate unless the top 100% point is reset / calibrated frequently.
I was thinking about smart adapting algorithms, but all of them are abstruse. And I decided that the first algorithm must simple.
The existing algorithm calculates battery balance in AH.
If will be customers request, I can realize other algorithms.


> Can it be alternatively set to trigger based on a trailing endAmps setpoint?
Say my 100% trigger is:
4.15V, trailing amps drops to 0.03C
I see. I will add a task to add parameter "End of charged current, Amperes"
Is good?

> Can the user tweak the CEF or is that automatically calculated only?
Charge Efficiency is the ratio of input amps to put output amps back.
So, in a PSOC scenario, not getting back to 100%, if I take 70Ah out, I might need to put 75% back in to reach that same SoC%. CEF is thus 1.07

Some BMs automatically calculate this, but then let the user override manually.

Peukert should be adjustable, LI batteries can vary between the different chemistries, even 1.04 will affect SoC% accuracy over time.
Hm...
I can add this coefficients.
I see it as reasonable
 

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>> use cases for using LI batteries for purposes other than for just proplusion, EVs ebikes etc.

>> Such a battery monitor version would eliminate miles traveled for example.

You can use PW not only on EV. The first display can be tuned by the user. In a horizontal layout, only gauges and battery can't be tuned. In vertical can be tuned all display places.
So, just leave speedometer disconnected, and customize screen layout to eliminate speed / distance readouts?

______

So, is there currently a SoC% "gas gauge"?



Requesting that if not, combine with "Ah remaining". User should be able to set the "minimum Reserve Ah" point, and visually count down to that, not dead flat empty.

and to make it more accurate:

"100% Full definition, Voltage / endAmps"
examples:
4.05V, any amps (CC Only)
4.15V, 0.05A
4.2V, 0.005A

Obviously volts above are 1S, user could input pack-level voltage.

This will automate the "Reset 100%" function.

User should be able to manually push a button to override, reset SoC% point to 100% earlier in the charge cycle.



Also make CEF and Peukert variable values, with defaults but user-configurable.

Ideally CEF could also be auto-calculated, maybe store that value, averaging each cycle and display read-only next to the user-set value as a suggestion.
 

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Perhaps in future develop BMS integration, perhaps as an optional add-on module:

Allow outward communications of values measured, via CAN. Example http://docs.foxbms.org/en/latest/getting_started/communicating/communicating.html

Allow signal control of NO relays, perhaps integrate with an option board like this:

https://www.ebay.com/sch/i.html?_nkw=8+Channel+Relay+Module

Which could in turn control proper contactors like Gigavac GX16

Can already sense trigger parameters like SoC%, voltage, perhaps add temperature sensing?

The FOSS project foxBMS is a great reference source for code / documentation reference.
 

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I consider too much information from BMS display a hazard to driver.
In aviation it is desired that systems do not tell pilot anything unless there is a need: "it never says hello to you untill its getting on the redline overload" goes the song.

Do not get me wrong, for servicing android interface is godsend. You can check on every cellin line and see if the charger is working properly etc..

But for driving I rather would have a small sturdy (OLED) 2 line display mounted in the drivers view showing 2 of the basics in any combination.... graphic bar of SOC, Voltage, immediate Amps, maybe show top most and bottom most cell voltage in a pack.

Avarage human interface should only show like 1 or 2 things at once. Otherise you create distraction to drivers primary job.

But of course there should be an override display stating emergency condition. You want to know about that at once!
 
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