Multi-meter Recommendation??

[Gauss163]

[...] You can get a rough approximation of the state of charge of a Li-ion battery by looking at the open circuit voltage. But you won't find any reliable information about the state of charge (except fully charged and maybe completely discharged) of NiMH, alkaline, or LiFePO4 cells by looking at the voltage.

Not true. Unlike NiMh, Li-ion has very low hysteresis so there is a very close correlation between resting voltage and SOC (state of charge). Further, lead-acid typically has much higher hysteresis than Li-ion so the SOC inference is much more rough, e.g. see below from this paper. Note to HKJ: this is the scientific answer to your prior BLF question as to why NiMh SOC cannot be determined closely from resting voltage, i.e. voltage hysteresis is the primary culprit, i.e. the voltage depends nontrivially on the recent history, i.e. it depends on the particular path it took to reach the SOC, whether by charge or discharge, etc.

 

[Curious_character]

I was assuming that the battery had rested at open circuit for a sufficient length of time for the voltage to stabilize. This might be 12 hours or more for lead-acid and a few hours for li-ion. I don't think the dynamic charge-discharge hysteresis is relevant unless you're trying to determine the SOC during the charge or discharge process which wasn't my intent. Even after a long rest, the voltage for a given SOC differs with chemistry, temperature, cell age, and history, so I maintain that if you pick up two li-ion cells of different manufacture, history, and possibly chemistry (of which there are several), even identical open circuit voltages can indicate quite different states of charge.

c_c

 

[Gauss163]

I was assuming that the battery had rested at open circuit for a sufficient length of time for the voltage to stabilize. This might be 12 hours or more for lead-acid and a few hours for li-ion. I don't think the dynamic charge-discharge hysteresis is relevant unless you're trying to determine the SOC during the charge or discharge process which wasn't my intent.

No, here voltage hysteresis refers to resting voltage. The point is that - unlike Li-ion - many other chemistries (NiMh, lead acid, etc) have very high hysteresis, i.e. their resting voltage depends so heavily on their (recent) history (path of (dis)charges) that it makes SOC estimates very coarse - often so coarse as to be of little use.

Even after a long rest, the voltage for a given SOC differs with chemistry, temperature, cell age, and history, so I maintain that if you pick up two li-ion cells of different manufacture, history, and possibly chemistry (of which there are several), even identical open circuit voltages can indicate quite different states of charge.

Of course it depends on the specific Li-ion chemistry. But only a few are common at the consumer level, e.g. see HKJ's tables in Estimating remaining capacity in LiIon batteries. With such tables at hand you can obtain very useful capacity estimates from resting voltage (typically within a few percent). I do this quite frequently so I know well how accurate such estimates are. In particular, your claim that "You can usually tell if they're fully charged or fully discharged, but often not much in between" is way off the mark, since within a few percent is certainly "much in between" empty and full.

Further your remark that "no multimeter will tell you much about the health of some kinds of batteries" is also off the mark since one can measure IR with a multimeter - which reveals much about the health of a battery - esp. when tracked over time.

 

[Curious_character]

Ok.

c_c

 

[Schermann]

All interesting stuff but it does not make my battery pulse charging any more fun!

 

[IlluminationDomination]

I have Two inexpensive Ones. The first one is an ETEK. It is 5 years old and starting to have some issues.

I just got this Innova yesterday. I like it. So far so good. I only need them for my Enloops/Akaline but primarily my Lithium Ion 16340/14500/10440/18650/18350..ect! And maybe to check my car battery down the road.

 

[StandardBattery]

That Innova looks pretty nice for a cheap meter. I'd probably be too scared to use that 10A input on that meter, but as a basic voltage meter it looks good. If the battery loads are appropriate, that's a great feature for a cheap home/kitchen meter. I'm not sure i'm buying the Cat rating unless it's just for the two inputs which seems kind of fishy to me.

 

[BVH]

Another Fluke 115 owner and recommender. It's fairly cheap and very accurate. It agrees 100% at 2 decimal places at 5V, 12V, 28V and 36V and 48VDC with my brand new Keysight 34465 6.5 digit benchmeter which is absolutely accurate to 3 decimal places and in many other cases, 4 decimal places, sometimes 5. All of this is DC.

 

[IlluminationDomination]

Another Fluke 115 owner and recommender. It's fairly cheap and very accurate. It agrees 100% at 2 decimal places at 5V, 12V, 28V and 36V and 48VDC with my brand new Keysight 34465 6.5 digit benchmeter which is absolutely accurate to 3 decimal places and in many other cases, 4 decimal places, sometimes 5. All of this is DC.

Where did you get yours and how much did it cost?

I saw them on Amazon from $105 to $155.

I guess fairly cheap is a matter of perspective. I have seen other brands/models for over $1000! Compared to them it is fairly cheap!

 

[Enderman]

I use a UT61E, uni-t makes great budget meters.
Almost all my measuring devices are from them.

 

[BVH]

I typically buy these types of items online from whomever has them at the cheapest price incl no tax and free shipping. I used "fairly cheap" in relation to what many of us here on CPF pay for flashlights $100+. Yes, about $150 is the typical price you see today for the 115. Over my many years on the planet, I've learned to buy once. I used to buy the cheapest items only to find myself upgrading to the same but higher quality item at a later date so I ended up spending more overall.

 

[StandardBattery]

Where did you get yours and how much did it cost?

I saw them on Amazon from $105 to $155.

I guess fairly cheap is a matter of perspective. I have seen other brands/models for over $1000! Compared to them it is fairly cheap!

For a quality meter that's a fairly cheap price. If you look at other Fluke meters you will see it's fair to classify it as fairly-cheap. Watch for sales, but I doubt you would find it for under $100 new. At $105 I'd say it is an excellent deal, and I'd be worried something was not right with the seller/deal.

The meter has a good reputation, and has enough of a history that the reputation is meaningful. Still, most people don't need even this level of a meter, but buy once and be happy is a good approach. Hobbyists often favor more functions over quality so they have can try and do more things. Fun is an important element to keep in a hobby.

 

[Schermann]

Nothng fun about DMMs! You use them, hope you don't get shocked and trust the measurement is accurate. Then you pack it away until next time.

I got a second hand Fluke 88V that tested accurate and I now I have none of those worries.

You get what you pay for.

 

[StandardBattery]

Nothng fun about DMMs! .....

Wrong, DMM can be lots of fun using various, sometimes advanced features to investigate and experiment with different devices. some times you just need a tool, like sometimes you just need a way from a to b, but sometimes you want to do it in style, and others you want to make sure it is fun.

If you need a tool, make sure it's a good one.

 

[Schermann]

Wrong, DMM can be lots of fun using various, sometimes advanced features to...

... do what exactly, that is 'giggle' fun?

Don't get me wrong, I luv using my Fluke. The quality and reliability of results is very rewarding. But a fun thing to just play with it IS NOT! It does what it does and it does it well but beyond that it makes for a good 'door stop' at best.

 

[david.allie]

If you need a tool, make sure it's a good one.

I fully agree. I've ordered a Neoteck DM6000pro (upgrade of PM18) with 6000 count resolution. This one was only $34 through Amazon.

My research discovered that Greenlee multimeters are re-badged Brymen units that seem to be very highly regarded (obviously not at the level of Fluke meters). I'm considering the Greenlee DM-830A, which is identical to the Brymen BM827s DMM, as a secondary unit. The Greenlee multimeters are also available on Amazon. I'm going to compare the other Greenlee vs Brymen DMMs because I don't need all the bells and whistles of the Greenlee DM-830A... something about half that price should meet my needs fine.

One of the little nit-picks I've discovered I have is with the display on a DMM. Personally I prefer the paper-white backlit displays... got to appease my aging eyes!

Enjoy your new multimeter!

 

[python]

Fluke 17B+ and a Sony VTC6

 

[StandardBattery]

I fully agree. I've ordered a Neoteck DM6000pro (upgrade of PM18) with 6000 count resolution. This one was only $34 through Amazon.

My research discovered that Greenlee multimeters are re-badged Brymen units that seem to be very highly regarded (obviously not at the level of Fluke meters). I'm considering the Greenlee DM-830A, which is identical to the Brymen BM827s DMM, as a secondary unit. The Greenlee multimeters are also available on Amazon. I'm going to compare the other Greenlee vs Brymen DMMs because I don't need all the bells and whistles of the Greenlee DM-830A... something about half that price should meet my needs fine.

One of the little nit-picks I've discovered I have is with the display on a DMM. Personally I prefer the paper-white backlit displays... got to appease my aging eyes!

Enjoy your new multimeter!

Yes, I have a Greenlee 510, I'm not sure which Brymen one it is, but it was one of their OEMs. In the past Greenlee has had sales, so you can watch for one and maybe get a very good price. I don't follow them so I don't know the current trend, but after Mr. Jones made Brymen popular it's been harder to find deals on them and even their rebadged ones. Still, as long as you don't get a lemon you do usually end up with a nice meter. Luckily I don't really need any more DMMs, but it's still nice to keep up with what's happening with them.

 

[Gauss163]

The Brymen's are high quality and typically offer far better price/performance than any Fluke. My primary handheld DMMs are Extech/Amprobe rebadged 500000 count Brymen BM859 (500000 is correct - not a fluke!). No Fluke comes even close to them at the same price point. DMMs are discussed extensively on EEVBlog.com.

 

[HKJ]

500000 count do not give any extra precision over 50000 count, only more resolution. Last I checked the meter do not even round numbers, i.e. 500009 in high res. mode is shown as 50000 in normal mode.
Brymen meters are fairly good, but there computer interface could use some improvement. It do not send numbers but a map of what segments are on in the LCD display (Fluke, Keysight and Gossen all send ascii values).