# available amp-hour meters



## DIYguy (Sep 18, 2008)

I have a high voltage CA also. I like Dimitri's Ah gauge.... http://minibms.mybigcommerce.com/template/files/EV Display User Guide.pdf


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## dtbaker (Jan 5, 2008)

DIYguy said:


> I have a high voltage CA also. I like Dimitri's Ah gauge.... http://minibms.mybigcommerce.com/template/files/EV Display User Guide.pdf



I do like the functionality listed.... but have heard that the Hall effect pickup (versus a shunt) doesn't do a good job of catching the low-amp flow; so the end of a charge during the CV phase may not be very accurate? true?


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## DIYguy (Sep 18, 2008)

dtbaker said:


> I do like the functionality listed.... but have heard that the Hall effect pickup (versus a shunt) doesn't do a good job of catching the low-amp flow; so the end of a charge during the CV phase may not be very accurate? true?


ya... .I don't know if this is accurate or not. Perhaps some users could jump in here. If so, is it enough to worry about? 

I was more interested in discharge...which would be at higher levels. So...does the meter count Ah and "fill up" as you charge? ... as opposed to a reset, then count Ah used as compared to input values of what should be "full"?


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## dtbaker (Jan 5, 2008)

DIYguy said:


> I was more interested in discharge...which would be at higher levels. So...does the meter count Ah and "fill up" as you charge? ... as opposed to a reset, then count Ah used as compared to input values of what should be "full"?


either type should show ah in as well as out... to track the times you have time for just a partial charge. My CA also has an external 'reset' button to take care of the eventual drift, as do most of the other units.

In my case I do a fair amount of mid-day partial charges when the car is parked between morning and afternoon errands, so it would be nice to have an accurate idea of what the SOC is....


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## Tahoe Tim (Feb 20, 2010)

Have you looked at the sensor made in Australia? I am following this thread to see what's out there. I need something that will interface to my car PC. I don't need a gauge.

http://www.evworks.com.au/index.php?product=INS-ZEVA-FGDP


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## Overlander23 (Jun 15, 2009)

How do standard sensors interface with your CarPC?


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## azdeltawye (Dec 30, 2008)

dtbaker said:


> I am wanting to learn more about the pros/cons of the currently available amp-hr counters and combo meters....
> ...


I'm very happy with the performance of the Brusa BCM400 Wh/Ah multi-function meter. The voltage and current measurement accuracy is dead-nuts on when compared to my fluke DMM. It uses a shunt with the D/A converter and measurement board mounted directly on the shunt itself and not in the gauge. This eliminates running the low-level signal shunt sense wires from the shunt to the gauge in the dash and greatly increases noise immunity. This is a very good design for a high noise environment such as a home conversion.

This unit has programmable PWM outputs so you can drive your factory gas gauge with the Ah or Wh count. This feature is very nice!

The only downside is the price. I got mine directly from Brusa for $700EUR which is crazy expensive!! But when compared to the ~ $10k of a Lithium pack I think it’s worth it...


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## Tahoe Tim (Feb 20, 2010)

I'm using a fusion brain with optional 4 channel voltage boards to interface to my carpc. I'm testing one 4 channel board now.

Look in the store on MP3car.com for details:

http://store.mp3car.com/Fusion_Brain_Accessories_s/41.htm


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## dtbaker (Jan 5, 2008)

Tahoe Tim said:


> Have you looked at the sensor made in Australia? I am following this thread to see what's out there. I need something that will interface to my car PC. I don't need a gauge.
> 
> http://www.evworks.com.au/index.php?product=INS-ZEVA-FGDP



this looks pretty cool. I would really like to use existing dash fuel needle for SOC. I do not have a tach for the amp display, but could get a small aftermarket one, but could get a simple shunt ammeter for less... I wonder if I could use the temp gauge (not accurate, but maybe good enought to see 1C to 5C; I dunno how you could calibrate it though.)


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## Tahoe Tim (Feb 20, 2010)

I haven't ordered on yet. I was hoping someone in the U.S. had them in stock. I also read about the two ways to calculate SOC and neither seems to be perfect. But something is better than nothing, I guess.


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## mcrickman (Sep 10, 2007)

DIYguy said:


> I have a high voltage CA also. I like Dimitri's Ah gauge.... http://minibms.mybigcommerce.com/template/files/EV Display User Guide.pdf


Who sells a product that has a open circuit board? Looks like these BMS suppliers are the only ones in the world who do. What's up with that?


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## Overlander23 (Jun 15, 2009)

PC component manufacturers, radio controlled component manufacturers... pretty much any application that doesn't require a finished cosmetic appearance because it will be used in something custom (computer case, for example) or somewhere that doesn't matter (in an industrial use), or an application that doesn't require a degree of electronic shielding afforded by a case, or doesn't require a degree of protection afforded by a case because of how/where it will be used.


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## ElectriCar (Jun 15, 2008)

I like the EVision the most of all I've seen. It's also the most expensive I believe. However, it has the ability to drive the factory fuel gauge provided it's not of the stepper motor type. Since I wanted to do that anyway, it equates to knocking $300 off the price. They run about $1000.

Since I'm wanting to go sans BMS, one feature I really like is the ability to divide your pack in half for monitoring purposes. Instead of one wire for every cell, you have three for the entire string. There's an LED ring around the gauge and as long as your pack is pretty well balanced the center led will be lit or maybe one either side of center. Should you have an issue arise in the pack somewhere it will show up on this gauge by the led shifting a lot off center. 

It also has a DTE display, distance to empty which is selectable in the software that comes with it. You have a 200Ah pack for instance but you want it to show empty at 180 you can. Oh yea, you program it with a serial cable to your computer.

Also there are 20 "pages" they call them selectable by remote in car device. The pages are groups of three parameters, ie Amps, Volts, SOC, Pack Balance, Ah remaining etc. that you can customize to your liking. 

Here's a link. And it's a nice looking gauge to boot. I'm just having a hard time accepting the price of it but I'm probably going to spring for it anyway.


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