# choice of instrument gauge



## 57Chevy (Jan 31, 2020)

just for reference, GPS speedos can suck pretty badly at times. If you start moving and they don't have a fix, they sometimes need to stop for a few minutes to get a fix, particularly if cloudy. They also don't work very well on cloudy days, in tunnels... They are also not legal in some countries. I did 13000 miles with one as it was easier than fixing the OEM speedo at the time and I'd often have to wait for it to fix before taking off.

To answer your question, I'd have the most critical temperature, inverter or motor and battery charge state wired to the OEM temp and fuel gauges. That is what I am doing, once I figure out how to get can signals output as low side drive analog 12V. For the speedo there are various options for electric motor drives which go on the gearbox end of the speedo cable and take a can signal.


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## niklaskinn (Nov 27, 2021)

57Chevy said:


> just for reference, GPS speedos can suck pretty badly at times. If you start moving and they don't have a fix, they sometimes need to stop for a few minutes to get a fix, particularly if cloudy. They also don't work very well on cloudy days, in tunnels... They are also not legal in some countries. I did 13000 miles with one as it was easier than fixing the OEM speedo at the time and I'd often have to wait for it to fix before taking off.


Nice to know. i still want to go with that solution and then think that a tachometer then I can always use this in case of failure of gps


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## remy_martian (Feb 4, 2019)

You need an odometer that is dedicated to the car or, barring that, a runtime-hours meter.


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## windraver (Aug 29, 2021)

I was looking into this in my CRX EV build. I'd say put any speedometer cluster you want and get the speed input data needed to utilize your cluster.

In the case of my 1986 CRX, I actually have a 2001 Honda Insight digital cluster which requires an electrical vehicle speed sensor input. The Leaf motor I'm swapping in doesn't provide that signal as they use wheel speed sensors.

So to mimic the VSS, also taking on the idea of how wheel speed sensors work, I pick up a hall sensor from racepak. It looks like this:










I then picked up a collar like this to attach to my axle:









I would need to mount the sensor in a stable position where it would detect the magnet passing. Some people mount it on the rear wheels. Etc.

From there, we need to convert that input out to the speedometer. If your vehicle uses mechanical speed input, speedhut sells an adapter to convert digital to mechanical.

For me I need to correctly scale the pulses to match the input expected by my speedometer which I'm planning to try to use this:










Amazon.com



In the end, the goal for me is to use my own speed cluster. If you don't like your current one, you can change it. As other said, speed by GPS has flaws where you might lose signal and that has reliability issues. Start with what cluster design you like, then work backwards to make it work is my suggestion.


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## niklaskinn (Nov 27, 2021)

Thanks for you replay windraver. 
I will se if I can get the speedometer I like in a non gps version.
Then I think I will go for the this 4 gauge. 

State of charge 
Temp on engine/inverter.
Ampere meters
Tachometer


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## windraver (Aug 29, 2021)

niklaskinn said:


> Thanks for you replay windraver.
> I will se if I can get the speedometer I like in a non gps version.
> Then I think I will go for the this 4 gauge.
> 
> ...


Yea I just did a POC with my Honda CRX using a Honda Insight cluster because I like those fancy digital clusters and I got it working. So find the style you like then figure out how to make it work for whatever you're installing it into.


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## remy_martian (Feb 4, 2019)

You don't need a tach on a fixed ratio gearbox. A speedo is basic equipment for roadworthiness in many places...that gets you an odoneter in most cases. 

Otherwise, an hours meter is useful in place of the odo for maintenance & valuation

Buyer: "how money miles/hours on it since the conversion?"
You: "I have no idea...."


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## niklaskinn (Nov 27, 2021)

remy_martian said:


> You don't need a tach on a fixed ratio gearbox. A speedo is basic equipment for roadworthiness in many places...that gets you an odoneter in most cases.
> 
> Otherwise, an hours meter is useful in place of the odo for maintenance & valuation
> 
> ...


I go for an ordinary speedometer with obd counter. 
I have a gearbox on so I could use tachometers in som cases but it is not very necessary.


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## niklaskinn (Nov 27, 2021)

Speedhut have a nice selection of gauges for ev conversion.


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## dlud (Jul 19, 2021)

I don't see these on Speedhut's website.


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## niklaskinn (Nov 27, 2021)

dlud said:


> I don't see these on Speedhut's website.


No i have got them from there support. 
there wep is not updated but they can make all for the EV conversion both with can signal or analog. 
pretty cool I think.


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## brian_ (Feb 7, 2017)

niklaskinn said:


> Speedhut have a nice selection of gauges for ev conversion.
> 
> View attachment 126624
> 
> ...





dlud said:


> I don't see these on Speedhut's website.


Perhap they could be selected by the Speedhut Customizer, with custom "logos" for labelling?


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## niklaskinn (Nov 27, 2021)

Yes they can do it just like you want. 
money can do anything 💸


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## dlud (Jul 19, 2021)

niklaskinn said:


> No i have got them from there support.
> there wep is not updated but they can make all for the EV conversion both with can signal or analog.
> pretty cool I think.


Yes, they look very cool. I'm interested.


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## niklaskinn (Nov 27, 2021)

dlud said:


> Yes, they look very cool. I'm interested.


Zero EV use them in there mx5









I will use 3 of them in my Nissan
1 speedometer an
2 dual gauges for temp an amp meter


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## dlud (Jul 19, 2021)

Where did you source them? Direct from Speedhut?


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## niklaskinn (Nov 27, 2021)

dlud said:


> Where did you source them? Direct from Speedhut?


Yes I will get it directly from speedhut.


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## niklaskinn (Nov 27, 2021)

Just an update for the gauges from speedhut.
the order is set am I got the first picture from them.


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## brian_ (Feb 7, 2017)

niklaskinn said:


> Just an update for the gauges from speedhut.
> the order is set am I got the first picture from them.
> View attachment 127808


What's "KM/T" supposed to be? Speed, in *km/h*? I can't tell if it's a typo (a good reason for sending artwork proofs) or something deliberate that just isn't apparent to me.

It's also strange to have yellow and red zones on a speedometer. That could indicate motor speed, but it would only make sense when using one specific transmission gear. Is marking zones on a speedometer a local thing there?


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## dlud (Jul 19, 2021)

How is the battery level calibrated?


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## remy_martian (Feb 4, 2019)

Converting their tach to a speedo doesn't work. Clearly, there's a stack of metal plates in China waiting for white silkscreen.

So much awful there.

I'd use a tach plate for a Speedo, marked accordingly

Battery temperature needs a red zone above 70C (or whatever your cell freakout temperature is) unless you use tricolor LEDs in the holes.

Battery SoC needs a red at 10% unless tricolor LED in hole.

Amps needs green to max continuous, yellow for peak, red for yikes.

Need an outlet temperature for DU cooland/oil and inverter outlet coolant temperature.

I prefer the cat pee yellow vs bird poop white for the lettering/markers, but that's just a matter of one of us lacking personal taste 😂


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## TeZla (Feb 18, 2021)

the battery temp scale could probably be half of that. If your getting up to 100c in the battery, its probably already on fire.
You've got the whole gauge, may as well use it.

I like the amps gauge though, Thats a good one


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## remy_martian (Feb 4, 2019)

According to tests from NASA, an 18650 cell doesn't light off until 120C on its case.



https://www.nasa.gov/sites/default/files/atoms/files/therm_runaway_test_18650_li-ion_clobato.pdf



If you're trying to hit max rate charging, you're running the cell cases at 45C-50C for at least a dozen minutes. Half scale would not work, as you'd get zero visibility to a creeping heatup during charging due to a failed cooling loop.

Depending on your sizing and method, of cooling, I suspect you could see _excursions_ to 60-70C during charging. So top end, 90C would be my choice. Which is still not 4th of July fireworks, according to NASA.

At the other end, to at least zero degrees C.

So, for my cars it would be

maybe orange -30-0C
yellow 0-15C,
green 15-xC
yellow x-60C with a "SC" mark at 45 or green from 40-60C
orange 60-90C

x is TBD - maybe someone has a rational basis for its bottom end value. Is yellow warranted during regular summer days in places like Thailand, where Bjorn Nyland found the cars to be running near peak efficiency in a place that normally is 35-40C in summer? I submit it's 40C. And 40-60 is SC*

*and super scoot current mode


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## remy_martian (Feb 4, 2019)

Maybe shade the regen sector of the ammeter?


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## niklaskinn (Nov 27, 2021)

brian_ said:


> What's "KM/T" supposed to be? Speed, in *km/h*? I can't tell if it's a typo (a good reason for sending artwork proofs) or something deliberate that just isn't apparent to me.
> 
> It's also strange to have yellow and red zones on a speedometer. That could indicate motor speed, but it would only make sense when using one specific transmission gear. Is marking zones on a speedometer a local thing there?



I live in Denmark where hour is time so it is called km/t.
The yellow and red are because it was made such original on datsun z.
You can also see my speedometer at the top of the thread there is a line from 100km / h and up


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## niklaskinn (Nov 27, 2021)

remy_martian said:


> According to tests from NASA, an 18650 cell doesn't light off until 120C on its case.
> 
> 
> 
> ...


battery temp scales to keep it slightly similar to battery SOC


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## niklaskinn (Nov 27, 2021)

dlud said:


> How is the battery level calibrated?


I make a canbus conversion from theNissan leaf canbus an send it to the gauges.


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## remy_martian (Feb 4, 2019)

niklaskinn said:


> I live in Denmark where hour is time so it is called km/t.
> The yellow and red are because it was made such original on datsun z.
> You can also see my speedometer at the top of the thread there is a line from 100km / h and up
> 
> View attachment 127827


One of the Scandanavian countries did traffic fines as a percentage of annual income, so is the red more than a year, then?


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## remy_martian (Feb 4, 2019)

niklaskinn said:


> I make a canbus conversion from theNissan leaf canbus an send it to the gauges.


Do you have a comprehensive list of the gauge CAN messaging as well as Leaf CAN messages you could either link or post here, so when people want to hook up their gauge faces they can cobble up scale converters etc?

A lot of Leaf conversions in this forum (too puny for me)...it's the Warp9 of the 2020's


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## niklaskinn (Nov 27, 2021)

yes we have some harsh fine penalties. max speed on highway is 130km / h. if you go higer Them 200km / h they take the car from you and sell it on action then the money goes to the state

I will get back with the canbus project wen I’m ready with the gauges


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## brian_ (Feb 7, 2017)

niklaskinn said:


> I live in Denmark where hour is time so it is called km/t.


In the International System of Units the symbol for kilometre is "km", not "KM", regardless of language. The symbol for "hour" is "h", regardless of the word commonly used in the local language for hour (which I now know is "_time_" in Danish, spelled like the English word but meaning a specific unit .... and pronounced "teem"). Using "T" makes sense to you and it's your car, but using non-standard symbols for standard units is not good practice in general... and even if you prefer the "T", I think using the lowercase "km" would be better, to keep at least the "kilometre" part using the correct symbol.

By the way, "T" is a valid symbol for a unit... the tesla, the unit of magnetic flux density. So "km/T" would be "kilometres per tesla".  Ironically appropriate for an EV, but still physically nonsense. The lower-case letter "t" is not a unit symbol, so I suppose that "km/t" for "_kilometer i timen_" wouldn't be so bad.



niklaskinn said:


> The yellow and red are because it was made such original on datsun z.
> You can also see my speedometer at the top of the thread there is a line from 100km / h and up
> View attachment 127827


Okay, I get wanting the authentic marking feature. It makes no functional sense so it would annoy me, but I suppose it's harmless... and of course it's your car!


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## niklaskinn (Nov 27, 2021)

today I received my gauges from speedhut an I’m really happy. 
now I will paint the cover around them.


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## brian_ (Feb 7, 2017)

Although I participated in this thread, I didn't notice where it was in the forum... it is in what is supposed to be a wiki, rather than the discussion forums. Perhaps a moderator (I guess that's you, Matt ) could move the entire thread to where it belongs, in _EV Conversions and Builds > __Technical Discussion_?


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## brian_ (Feb 7, 2017)

Just curious, niklaskinn... why did you choose this style for the dual gauge, instead of the "alternative sweep option" (shafts on the outside, needles extending inward) which gives a longer needle and longer (more readable) scale for the same sweep angle in the same face size?


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## niklaskinn (Nov 27, 2021)

unfortunately I did not have many options to choose from so it was the best option.


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