multimeter blues

[KarlMaldensNose]

See my post count and deduce my knowledge base. I'm trying and reading and learning but I feel like I'm drowining so I have to ask b/c I can't find on my own the info I need on this one. So please, oh please, do not point me to the search function.

My dilemma is multi-part but I'll try to keep this relevant to this particular sub-forum. Basically I need to know if these multimeters are what I need to check my batteries so they don't get ruined or ruin my flashlights. Or are they not the correct kind or not accurate enough?

Here are the multimeters in question.
http://www.batteryjunction.com/a-dt-9205a.html

http://www.thesource.ca/estore/Prod...=Online&category=Multitesters&product=2218202

My batteries are on order and will arrive any day now. I have never used li-ions before (and, yes, I am doing my homework before I use them). I bought two AW R18650 2600mah and two AW RCR123A 750mah from 4Sevens. The charger is the Cytac 139 dual bay also from 4Sevens. But I've been reading (post-purchase:ohgeez:) negative reviews/opinions of this charger b/c it doesn't have a CV charge method, thus allowing it to trickle past the 4.20 V spec right up to ~4.25V and it doesn't have auto termination... hence the extreme importance of a proper multimeter/voltmeter.

This charger and the batteries were purchased to go along with my new Lumapower D-mini VX, which runs 1x18650, 1xRCR123 or 1xCR123. I plan on soon picking up another light that runs on these cells as well.

So, about the multimeters... if they're not appropriate is there one available in Battery Junction's battery testers/analyzers section that is? I ask about that web store specifically b/c I already have an order placed with them for the D-mini which should be shipping out on Monday, so I can still add to the order for the next day or so. Also, yea or nay on the charger?

Thanks, guys.

 

[HKJ]

They can both be used but you do net get any extra digits. I do not like the meter from "thesource" because it uses the same terminal for current and voltage, this increases the risk of blowing the meter up, due to a mistake.

The case with the digits is because the maximum reading on the meters are 1999, to measure 4.20 volt the meter can only use the last 3 digits, i.e. you do not get any extra digits, this will give a bit extra error to the reading.
The reading will be exact enough to keep you safe, but if you want better precision you must look for a meter with more digits or a 4999 or more in maximum reading.

Another problem present on cheap DMM, is when the battery is low, many meters do not show any warning, but only a wrong reading. To avoid this, either buy two meters or a cheap voltage reference, that can be used to verify the meter.

 

[KarlMaldensNose]

Thank-you, HKJ. I appreciate your opinions and efforts.

I appreciate that he showed me the problem with those meters, but nodoby else has anything else to say about my situation? Really? Is it in poor taste to recommend a half-decent, passable voltmeter/multimeter to a noob? One that can be had from a well-know internet retailer... Or maybe it's in poor taste for me to ask.

I've done lots of research, and I just can't find a meter with more than a 4-digit reading anywhere for under $60.00.

If no suggestions, I'd be almost as grateful if a wave of people came forward telling me those 4-digit models are fine for simple battery checking and that many CPF'ers use them with success.

 

[65535]

I personally only recommend Fluke, new they come with a hefty price tag, but I believe firmly that you can find a good deal on a good condition Fluke on eBay in your price bracket.

Check out eBay for Fluke 87 or Fluke 85 meters, they'll do exactly what you want, be just about the best you can get and be reasonably priced. I checked and there are a few if you're willing to go bidding.

 

[HKJ]

I appreciate that he showed me the problem with those meters, but nodoby else has anything else to say about my situation? Really? Is it in poor taste to recommend a half-decent, passable voltmeter/multimeter to a noob? One that can be had from a well-know internet retailer... Or maybe it's in poor taste for me to ask.

I've done lots of research, and I just can't find a meter with more than a 4-digit reading anywhere for under $60.00.

I do not know what cheap meters are sold in US or Canada. A usable meter is Extech EX510 but the price is above $60.

If no suggestions, I'd be almost as grateful if a wave of people came forward telling me those 4-digit models are fine for simple battery checking and that many CPF'ers use them with success.

They are ok for battery checking and many CPF'ers uses them, but you will have the problems I mentioned above (and a few more if you use it for other measurements)



If you want another opinion about multimeters, there are comparison of some meters here:
$50 meters $100 meters

But they are evaluated for everyday use in electronic, not flashlight use.

 

[45/70]

They can both be used but you do net get any extra digits......

The case with the digits is because the maximum reading on the meters are 1999, to measure 4.20 volt the meter can only use the last 3 digits, i.e. you do not get any extra digits, this will give a bit extra error to the reading.

I agree with HKJ, for the most part. I think however, that too much emphasis is placed on the number of digits. The accuracy of the meter itself, and whether it is calibrated regularly, has more to do with accuracy than the number of digits.

It is entirely possible to have a 1999 count 3 1/2 digit meter that is more accurate than a 19,999 count 4 1/2 digit meter, or a 6000 count 3 3/4 digit meter, unless the inherent accuracy is similar, and the calibration is kept current. You may be a digit short, but the 3 1/2 digit meter may read 4.20 Volts vs. 4 194, or 4.206 on the other meters, when the actual "real" voltage is in fact, 4.20 Volts. In this case, the extra digit is just giving a false sense of security.

Don't get me wrong, if I could justify it, I'd have a Fluke 8808A, or similar unit (maybe an Agilent? :)) like a friend of mine has. There's just no way I can justify one though. An accurate 3 1/2, or 3 3/4 digit DMM will work for 99.9% of most electrical/electronic use.

As for cheap meters, personally I've avoided them, unless you count the $100+ Micronta I bought about 15 years ago ( weak moment:candle:). On the other hand, I've never really had the need for a more expensive model either. Most of the DMMs/meters I've bought from back in the analog days to the present, were $50-$100 units. I just figure when your looking for something that's goal is to represent some sort of accurate measurement, that the bargain basement isn't the place to look. :)

Dave

 

[Black Rose]

Basically I need to know if these multimeters are what I need to check my batteries so they don't get ruined or ruin my flashlights.

I use the Innova/Equus 4320/4320a DMMs you see on sale regularly at Canadian Tire and sometimes at Part Source.

I don't see the 4320 on their (CT) site anymore, it seems to have been replaced with the 3310.