Multimeter guide.

[shirley_hkg]

Remember this ? If I were correct , the cell monitor drains 45mA .

Just tested my 210E , it reads 20mA .

[shirley_hkg]

Leakage clamps will be accurate enough to mA .

They cost $100.00

[Burgerman]

Just needs a push on (momentary) switch in the neg wire. Then wont drain a thing unless you push the button. I don' think its possible to get a clamp meter that measures accurately for small currents any cheaper than about 150 dollars. Sadly.

Those clamps above DISPLAY 1mA. But accuracy limited to less than 1.5% of 60A.
So they will be no more accurate than your red one? (good to a real 40mA)?

http://www.mjlorton.com/multimeter-revi ... amp-meter/
What we need is a meter at your price with this low current capability!

[c500user]

http://www.eevblog.com/forum/testgear/a ... -t-ut210e/

better than I expected

[Burgerman]

https://www.youtube.com/watch?v=89HDlSq8WEg

Here too. As long as you don't move it after zero.

So pretty good for that money! Watched a few video reviews. Can do low mA quite well, as long as you zero it in position and don't move it or handle it.

[terry2]

http://www.ebay.co.uk/itm/UNI-T-UT203-Digital-Handheld-Clamp-Multimeter-Tester-Meter-DMM-CE-AC-DC-Volt-Amp-/351149081329?hash=item51c21dc2f1:g:oJcAAOSwxH1T40f4 20 includes delivery. Not super accurate and keeps needing re-zeroing by pushing a button, but 20 pounds inc delivery?

I went to buy one but I them realized I couldn't put it on the motor wire as it's tucked away.

[Burgerman]

True. You need to un-tuck it! And only ONE motor cable to each motor, not the pair. Easy enough, they are usually inside bits of pvc sleeve, and wires visible at the end. Or trim some PVC...

[terry2]

True. You need to un-tuck it! And only ONE motor cable to each motor, not the pair. Easy enough, they are usually inside bits of pvc sleeve, and wires visible at the end. Or trim some PVC...

No can do on a Puma 40. The cable goes in then to the front and there is no excess wire to pull out.
In fact the Puma 40 is a pain to work on.

[Burgerman]

You can measure anything on any chair. It just depends on how much effort you put in. If you expect it to work by magic that's not going to happen.

[terry2]

You can measure anything on any chair. It just depends on how much effort you put in. If you expect it to work by magic that's not going to happen.

It would take more then magic. You do realise there is only 1 inch of space at the top of the battery where the two motor leads run?
To get to those leads you have to lower the battery bay. Take out both batteries and then and only then can you see them.
The shops have a special left for these chairs which you can't buy.

The Puma 40 is micro managed which nice for the looks and stuff but a pain for a person. I know..I got one.

[rover220]

You can measure anything on any chair. It just depends on how much effort you put in. If you expect it to work by magic that's not going to happen.

It would take more then magic. You do realise there is only 1 inch of space at the top of the battery where the two motor leads run?
To get to those leads you have to lower the battery bay. Take out both batteries and then and only then can you see them.
The shops have a special left for these chairs which you can't buy.

The Puma 40 is micro managed which nice for the looks and stuff but a pain for a person. I know..I got one.

you are correct, motor loom very short on the puma but it could be done with some effort

[Burgerman]

You can make a temporary extension loop. As I did here www.wheelchairdriver.com/gopro/motoramps.mp4

[JoeP]

You can make a temporary extension loop. As I did here http://www.wheelchairdriver.com/gopro/motoramps.mp4

Extended loop... smart!

I almost pulled the trigger on that $35 clamp meter but with my shaky hands I figured I'd better not.

I've had this clamp meter saved on my Amazon account for a while
https://www.amazon.com/gp/product/B001T ... DKIKX0DER1

Thoughts?

[Burgerman]

I did this to show that a 100A controller on a 6mph chair is required. Had it been an 80A controller control or max torque required to turn at the same speed as the joystick was moved would be missing. That gives an 'elastic' sort of feel where the chair doesn't respond as expected.

Remember the 100A was limited by the controller. And that this is only ONE of the two motors.

[Burgerman]

I have that one. It can measure right down to the 1 or2 mA range accurately. Which is useful. But its limited to 100A. That may or may not be a problem for you.

Unless you use it for electronics or very small currents in the 2 to 30mA range you are better getting the https://www.amazon.com/Uni-T-UT210E-Cur ... =GTC+CM100 that shirley recommends. Much cheaper too.

[JoeP]

I have that one. It can measure right down to the 1 or2 mA range accurately. Which is useful. But its limited to 100A. That may or may not be a problem for you.

Unless you use it for electronics or very small currents in the 2 to 30mA range you are better getting the https://www.amazon.com/Uni-T-UT210E-Cur ... =GTC+CM100 that shirley recommends. Much cheaper too.

Thank you John, I'll do the Uni!

[Burgerman]

It drifts from zero a lot more than the more expensive options, and capacitance measurement is a bit limited. But for what you will likely need it for on a chair its fine. Going by online review/tests.

[shirley_hkg]

[shirley_hkg]

Haha , NEW TOY .

Accuracy is more than we need , just another shopaholic .

£30 , including rechargeable pack .

[Burgerman]

Accuracy is more than we need

Check it. You may be pleased. Or not!

I have a bunch of old meters here, many cheap ones.

And a fluke 289 with recent calibration certificate. http://www.fluke.com/fluke/uken/digital ... ?pid=56061 Also a cheap meter from the USA as it was new in box, but never used. I sent it for calibration regardless.

Some are surprisingly good. And some are surprisingly bad! The ones that are bad tend to be really bad. Some are only bad on noisy non simple voltages such as the pulsed charge voltages on the PL8 or logic circuits. Where they tend to read much higher than the actual RMS voltage. On the fluke I see 3 seperate voltages on logic circuits. Or they vary a lot due to temperature esp on lower mA or resistances. And I wouldnt use any cheap meter on mains voltages or higher if I were you.

But as you say, good enough for basic cell voltages as a comparison etc.
You can check: https://www.eevblog.com/forum/reviews/a ... -dmmcheck/

[shirley_hkg]

Yours has a 10X price tag .

[Burgerman]

I know, if bought new, but I like good tools. Eg, I want to see what voltage my van drops down to overnight. When solar doesent help any. So I leave my logging meter on it for 48 hours or so. Then I get a 2 day graph. And can then see what happens in detail, how low it gets, watch it go up to 14.4V CV and fall to 13.4 all day. And 12.7 at night. Etc. Logging is useful.

So as a DIAGNOSTIC tool, quite apart from being accurate, its very useful in other ways.

And a LOW impedance setting for measuring cable or motor impedance. Or shows AC and DC levels on a charge cable so you can see ripple etc. Or reads frequency, pulsewidth and shows levels simultaniously.

That said, if you dont need logging, uni-t meters are actually pretty good. Not like all the other junk chinese meters that I dont trust!

[Arima]

Been looking at dc current clamp meters today. This thread is a few years old, it was the best reference I found. Is the Uni-T B4Q094 UT210E still a good bargain for measuring current during charging? $50 usd on amazon today.

[Burgerman]

Yes.

[Arima]

Should be here Tuesday...hopefully in an unopened box.