[dtbaker]

I bought a cheap digital multimeter about a year ago.... and it has gone completely south; first the on/off switch broke, then the readings went haywire today, showing about a third of known voltage both DC and AC scales...

anyway, any suggestions for good quality, not too expensive, digital multimeter? source?

do the typical big box (lowes, homedepot, etc) stores have any meters that are NOT junk?


d

 

[major]

I bought a cheap digital multimeter about a year ago.... and it has gone completely south; first the on/off switch broke, then the readings went haywire today, showing about a third of known voltage both DC and AC scales...

anyway, any suggestions for good quality, not too expensive, digital multimeter? source?

Hey dt,

I really like something like this http://www.mcmelectronics.com/product/TENMA-72-7226-/72-7226 I got the 1000A version. Being able to clamp around a battery or motor cable and read DC AMPS is a big plus for me. It also reads AC amps, AC/DC voltage, Resistance, etc.

You can get good multimeters at Sears, Lowes, etc, but also crappy ones. You usually get what you pay for. I have good ones for my shop and lab, but cheap ones for my barn. But then sometimes I use like 4 or 5 at once MCM seems a good place to buy from. Quick shipping. The Tenma meter isn't a Fluke, but not too shabby and less $. MCM does run sales. I bought mine for less than the web price. You might call and ask.

major

 

[dtbaker]

Hey dt,

I really like something like this http://www.mcmelectronics.com/product/TENMA-72-7226-/72-7226 I got the 1000A version. Being able to clamp around a battery or motor cable and read DC AMPS is a big plus for me. It also reads AC amps, AC/DC voltage, Resistance, etc.

thanks!

I need to go shopping today to see if I can find comparable local, I JUST finished wiring up my new Thunderskies in car, and I really want to get an initial set of voltages before I button on the lids.

I don't think I need the amp clamp... so I'll probably go with a simpler version from that OEM if I can find one.

 

[PTCruisin]

I bought a Sears meter about a year ago that measures ac and dc current (clamp-on), voltage, resistance, capacitance, inductance, frequency and temperature for about $60. I didn't think I would use the clamp-on amp meter but I use regularly to check charging amps and as a second instrument to calibrate my Cycle Analyst.

The temperature measurement comes in handy too.

 

[nimblemotors]

I agree, having the clamp-on meter has been great, I use mine all the time when doing e work. I have a BK 267A, 2000amp.
http://www.bkprecision.com/products...ction-true-rms-current-clamp-meter-2000a.html
yep, it isn't cheap, but worth it if you want to see how many amps your motor pulls or battery.

I bought a Sears meter about a year ago that measures ac and dc current (clamp-on), voltage, resistance, capacitance, inductance, frequency and temperature for about $60. I didn't think I would use the clamp-on amp meter but I use regularly to check charging amps and as a second instrument to calibrate my Cycle Analyst.

The temperature measurement comes in handy too.

 

[dtbaker]

I bought a Sears meter about a year ago that measures ac and dc current (clamp-on), voltage, resistance, capacitance, inductance, frequency and temperature for about $60. I didn't think I would use the clamp-on amp meter but I use regularly to check charging amps and as a second instrument to calibrate my Cycle Analyst.

The temperature measurement comes in handy too.

hhhmmm, you are talking me into clamp amp meter... I am finding my cycle analyst wandering a bit, and since it is now my ONLY instrumentation i really want i to be accurate.

can you expand a little on your calibration technique?

I guess you can check pack voltage against CA readout, and adjust the voltage ratio.... but how do you check the amps? during charging? That would only be around 10 amps.... hard to see much error isn't it? Unless you have an exposed cable in cabin where you can read while under load driving?

 

[PTCruisin]

hhhmmm, you are talking me into clamp amp meter... I am finding my cycle analyst wandering a bit, and since it is now my ONLY instrumentation i really want i to be accurate.

can you expand a little on your calibration technique?

I guess you can check pack voltage against CA readout, and adjust the voltage ratio.... but how do you check the amps? during charging? That would only be around 10 amps.... hard to see much error isn't it? Unless you have an exposed cable in cabin where you can read while under load driving?

I have a battery box beneath the rear seat so I removed the seat and clamped on to one of the conductors. I was able to read the battery amps and the cycle analyst simultaneously (my brother was driving) to determine how to adjust the shunt resistance in the cycle analyst to make both meters read the same amps.

I don't think the shunt is very accurate and I have to re-zero the amps readout on the cycle analyst almost daily. I am looking at replacing the shunt with a hall effect current sensor.

 

[dtbaker]

hhhmmm, I may start another thread regarding the cycle analyst specifically.... I am seeing it wander a bit too, and perhaps this is why the more expensive multi-metering instruments all see to go to the hall effect sensors.

I am seeing the CA amps un-zero rapidly, and the difficulty in accurate calibration at 'normal load' amps seems to be hit or miss and leading to a less than solid feeling on the accuracy of amp-hr consumed. The voltage should be easily calibrated once I get a decent multimeter though.

 

[RKM]

Dan,

I'm with the crowd re. the clamp on ammeter. I don't have one and wish I did, for the same reason you are talking about. I think my CA is reading high on amperage and I'd like to proof it against an ammeter. A meter with a max hold feature would allow me to drive the car, note the max reading on the CA and compare it to the clamp meter.

Rob

 

[dtbaker]

ended up buying a multi with 400 amp ac/dc clamp ammeter functionality at sears today for $59.... supposed to be calibrated +/- 0.5%, so that is pretty good!

 

[PTCruisin]

ended up buying a multi with 400 amp ac/dc clamp ammeter functionality at sears today for $59.... supposed to be calibrated +/- 0.5%, so that is pretty good!

Yep. That's the one I bought. It's been reliable so far.

 

[dtbaker]

ok, I fired this thing up today, and noticed that the display floats all over the place when the leads are not touching anything... rather than reading 'zero'. Not confidence inspiring?!

In the fine print, the unit i rated for operation up to 6000' ft elevation. I am at 7000'... could this really affect a volt/amp reading?

 

[major]

ok, I fired this thing up today, and noticed that the display floats all over the place when the leads are not touching anything... rather than reading 'zero'. Not confidence inspiring?!

In the fine print, the unit i rated for operation up to 6000' ft elevation. I am at 7000'... could this really affect a volt/amp reading?

Hi dt,

Sounds weird, but maybe the altitude screws up the display or something. Does it settle down when measuring a voltage or resistance? I have seen meters float around when they are open circuit. Auto range is looking for microvolts or something and reading noise.

If the meter won't work, return it and inquire about your altitude requirement before next purchase. Maybe see if you can find a specification for a Fluke meter regarding altitude.

major

 

[dtbaker]

Does it settle down when measuring a voltage or resistance? I have seen meters float around when they are open circuit.

yes, it does seem to settle.... I have not had a auto-ranging meter before, so probably just thrown a little by non-zero float.

I am having trouble calibrating the cycle analyst.... measure pack voltage, set the v ratio in setup and got the numbers to match prior to full charge, but note that readings on multimeter and CA diverge as voltage rises at end of charge, and probably as voltage goes down but that is hard to see with sag only occurring under heavy load.