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what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 12:24am
by sharinginfos
HI
I like to make a good buy when i do a buying
Atm i only need to mesure voltage but maybe tomorow i will need other functions

i dont want to become an expert on multimeter.
i see 3 choices with like 15 doll difference below

wich should i choose?
i never had to use a multimeter and live in an appartement.

https://www.amazon.ca/KAIWEETS-Multimet ... s9dHJ1ZQ==

https://www.amazon.ca/KAIWEETS-Multimet ... s9dHJ1ZQ==

https://www.amazon.ca/AstroAI-Digital-M ... C81&sr=8-5

wich one is better for futur application and why

thanks

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 12:53am
by LewTwo
The last one will not measure AC voltage (i.e. what you have in your home).
The second has fuses for both Amp and Miliamps.
It is also likely accurate enough for a beginner.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 7:04am
by Comrade
sharinginfos wrote:
Sep 19 2022 12:24am
I like to make a good buy when i do a buying
None of those are a good meter by any definition.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 7:34am
by E-HP
#3 doesn't do AC as mentioned. #1 has too many oddball functions like the temp probe. Might be handy but not needed. #2 covers all of the basic functions you'll need.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 9:00am
by 4πr^2
Not sure what people are considering "#3" - but the third one on the list I see is the "AstroAI" for ~$18. It says and looks like it does AC and DC voltage to me, plus 'the usual' other functions... resistance, conductivity, etc. For general use, I suspect it would be more than accurate enough. You likely aren't going to be measuring amps, and if you do, amp draw on a bike is going to be much larger than most any meter, so you'd probably use a shunt and actually measure voltage across it. So I wouldn't worry too much about amp capacity of the meter.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 9:34am
by E-HP
4πr^2 wrote:
Sep 19 2022 9:00am
Not sure what people are considering "#3" - but the third one on the list I see is the "AstroAI" for ~$18. It says and looks like it does AC and DC voltage to me, plus 'the usual' other functions... resistance, conductivity, etc. For general use, I suspect it would be more than accurate enough. You likely aren't going to be measuring amps, and if you do, amp draw on a bike is going to be much larger than most any meter, so you'd probably use a shunt and actually measure voltage across it. So I wouldn't worry too much about amp capacity of the meter.
You're right. But, it also uses 9V batteries, which I try to avoid. A few battery changes and it makes up for the price difference with #2.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 9:38am
by Comrade
4πr^2 wrote:
Sep 19 2022 9:00am
You likely aren't going to be measuring amps, and if you do, amp draw on a bike is going to be much larger than most any meter, so you'd probably use a shunt and actually measure voltage across it.
Most good meters go up to 10A, which is plenty to do some calibration on an e-bike. At 48v that's 480W of power. The point of a good meter is that it is guaranteed to be calibrated. It becomes a reference tool against which other things are calibrated. It's like buying a typical Chinese ruler that is about 1mm off. Everything you measure and build with it will be off. :lol:

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 19 2022 10:10pm
by LewTwo
4πr^2 wrote:
Sep 19 2022 9:00am
Not sure what people are considering "#3" - but the third one on the list I see is the "AstroAI" for ~$18. It says and looks like it does AC and DC voltage to me, plus 'the usual' other functions... resistance, conductivity, etc. For general use, I suspect it would be more than accurate enough. You likely aren't going to be measuring amps, and if you do, amp draw on a bike is going to be much larger than most any meter, so you'd probably use a shunt and actually measure voltage across it. So I wouldn't worry too much about amp capacity of the meter.
Well it does not measure AC Amp's ... but the picture used by the vendor is somewhat misleading, so one has to read the caption closely: "... can not be used to test AC voltage of RECEPTACLE when dial is located in DC current range."
I admit that I quit reading as soon as it got "can not be used to test AC voltage" ... my bad.
No AC.jpg
No AC.jpg (56.03 KiB) Viewed 299 times

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 20 2022 12:45am
by calab
I'd price compare to keep my hopes high on spendy spendy but this one looks good if the work counted
https://www.eevblog.com/product/bm235/

For our adult toy kid hobby, if you can find a cheap meter that will read 12.34 digits, but any meter $10+ is suitable even if it only read 12.3 digits, just wait until theres a sale and snatch one up, or signal to your fellows with a used dirty Fluke and flex. If one came around, used, for a good price..... why not? Actually I ran across many, decided I had other priorities for the monies.

Mine reads 12.3 digits, and I still balance the cells manually. It kind of sucks to measure 58.8 volts and not 58.78 volts ya know.

Always best to have a minimum of 2 digital multi-meters, and lots of spare fuses and spare 9v batteries, even spare probes.... that fit ;)

I dont know about those links, I wouldnt trust those no-names.

I thought this guy would have something cheaper but this looks to be the cheapest $65aus out of stock :( which is like $40 usd, guess was close its actually $43usd.
https://www.eevblog.com/product/pm300/

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 20 2022 2:26am
by amberwolf
FWIW, the sub-$5 meters like HarborFreight used to give away (still available in a bunch of "brands" on amazon for less than $10) are good enough for just about all troubleshooting on an ebike, given that most of the things one needs to check are of the "is there a voltage and/or does it change" kind of thing, and knowing if it is 3.922v vs 4v isn't important. ;)

They're not truly accurate, as each one measures a bit differently :lol: but once you know how one behaves (such as measuring a few 5v USB chargers' output, etc and seeing if it correctly reads 5.0v, etc)., it's good enough for testing even batteries (balance testing for instance only needs to do relative voltages between groups/cells, to know which ones are off and by about how much).

I still keep a bunch of them around to test things I don't need my ancient Fluke 77-III for. ;)

I also have some of the in-between-quality meters, and for the most part they aren't enough better than the super-cheap ones, except for having MUCH better test leads, to be worth the significant difference in price (sometimes as much as 5-10x that of the super-cheapies). They may have more features, better ergonomics, etc., but they don't do their actual job enough better to be needed for most of the electrical/electronics testing I ever do (which has been quite a bit over the decades).


Current measurements on an ebike will require more than pretty much any of the cheap meters can handle, unless using a clamp-on meter, so it's generally irrelevant what they can test, current-wise, for the most part. (sometimes still useful for testing lighting, DC-DCs, idle current draw, etc).

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 20 2022 7:49am
by gobi
Before ebikes, I had to read up on lithium battery tech,
I found that I needed to figure dc amps with a CLAMP on meter,

This one does BOTH DC and AC amps (clamp on)

https://www.amazon.com/dp/B07Z398YWF

looks like it was a coupon, that makes it sweeter,

I would suggest this one or similar, clamp on feature ROCKS!

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 20 2022 10:37am
by marty
Doctorbass wrote:
Jan 15 2015 1:43pm
I would go with a FLUKE !!

Solid reputation
Accurate
Well built

That's a one-time buy!

Doc
Doctorbass wrote:
Oct 16 2007 10:29am
Buy a fluke and let you stop bordering you with innacurate cheap DMM :wink:

I know alot about multimeter and i have 9 different in my home lab.

some of those will have different reading because:

some have an internal load (like mastercraft that have a load to test 1.5, 6, 9 and 12V battery) they dont test in floating mode).. they will read lower value and it's the load that make the voltage droping a bit...

-some have cheap DAC and op amp ic and resistors that have tolerence that drift with temperature...

-some are affected by the soc of the battery that power the multimeter!.. a lower 9V battery give often higher reading!!!

-buy a fluke...

buy a fluke...

but a fluke...

... ....

... ...

Zzzzz zzzz zzzz...


Doc :wink:

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 20 2022 10:45am
by marty
amberwolf wrote:
Sep 20 2022 2:26am
FWIW, the sub-$5 meters like HarborFreight used to give away
Had a Harbor Freight free multimeter. Tried it. Quality was so low I would call it garbage. After a autopsy, Might be good for a fraction of a penny worth of scrap metal :(

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 20 2022 10:49am
by ebuilder
What Doc said. Fluke for life. That's all. Had others. Weren't as good.
Fluke.jpg
Fluke.jpg (1.01 MiB) Viewed 252 times

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 21 2022 12:42am
by sharinginfos
hi
thx for the answers,

the fluke are very expensive. the whole point of building my own battery is to save money and have good quality cells i bought used from Drbass prepandemic ill use the multimeter to try to put cells with same voltage in paralle. yes using a cadillac is fun but do i really need that to check the cells and stuff?
i mentionned that it would be nice that the multimeter can be used in home but i never had to use one so far and dont know exacty what feature are needed. Im not going to specialise in electricity battery building after i will have build a safe and fonctionnal battery wich is my goal

what i understand from your writing is tha no1 link has to many options , the no3 is not up to the task

So i guess i have to choose between the no2 and the clamp on

no2 is this the one at 23 dollar

https://www.amazon.ca/KAIWEETS-Multimet ... s9dHJ1ZQ==

the clamp on is 47 dollar acdc .https://www.amazon.com/dp/B07Z398YWF

I did not know that clamp multimeter existed. not sure when it can be a plus when building the battery and installing the hubmotor and wire.

can you give me hints one wich one would be best? both price are ok for me since i need one hoping it will last me a while
thanks

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 21 2022 1:16am
by amberwolf
sharinginfos wrote:
Sep 21 2022 12:42am
the whole point of building my own battery is to save money and have good quality cells i bought used from Drbass prepandemic ill use the multimeter to try to put cells with same voltage in paralle.
<snip>
i mentionned that it would be nice that the multimeter can be used in home
Ah, well, since you didn't tell us any of that, we couldn't know to suggest cheaper things. ;)

It would be best if you specified a budget that recommendations should not exceed.

Presumably for your battery build application, it only needs to measure DC voltages up to the max voltage of the battery. What will that be? (how many series cells (groups) will it have?)


Note that if you buy a meter only just capable of this, and need other capabilities later, you'd likely have to spend the same money (and probably more) all over again to get those. But if you never need the other capabilities, it might be a waste of money to spend on them now.

If I had to choose between the two options you linked last, I'd pick the clamp-on meter, as it is only about $7 more than the other, and can do significantly more, including the temperature and high-current measurement options useful for ebike testing. Whether one is really any better than the other, I couldn't say, never having used that "brand".


FWIW, the most commonly used meter modes for ebike troubleshooting are <200 DCVolts, Continuity, 2-20KOhms.

Measuring DCAmps is helpful in various kinds of testing, but usually you'd need to measure 20-30A ranges or higher to be useful; and often only while riding to do the testing under sufficient load--in those cases, a wattmeter is more useful and does more things for the money.

Temperature testing is sometimes useful as well.


AC measurements are almost never needed on ebike testing/troubleshooting, so if a meter doesn't have that function, it's not a big loss unless you think you will use it for household wiring troubleshooting (which I recommend leaving to experienced professionals if you are not yourself experienced at it, unless you first learn enough about it; it's too easy to make a fatal mistake testing or fixing household AC wiring stuff).



sharinginfos wrote:
Sep 19 2022 12:24am
I like to make a good buy when i do a buying
Atm i only need to mesure voltage but maybe tomorow i will need other functions

i dont want to become an expert on multimeter.
i see 3 choices with like 15 doll difference below

wich should i choose?
i never had to use a multimeter and live in an appartement.
<snipped links>
wich one is better for futur application and why
sharinginfos wrote:
Sep 21 2022 12:42am
the fluke are very expensive. the whole point of building my own battery is to save money and have good quality cells i bought used from Drbass prepandemic ill use the multimeter to try to put cells with same voltage in paralle. yes using a cadillac is fun but do i really need that to check the cells and stuff?
i mentionned that it would be nice that the multimeter can be used in home but i never had to use one so far and dont know exacty what feature are needed. Im not going to specialise in electricity battery building after i will have build a safe and fonctionnal battery wich is my goal

what i understand from your writing is tha no1 link has to many options , the no3 is not up to the task

So i guess i have to choose between the no2 and the clamp on
<snipped links>
I did not know that clamp multimeter existed. not sure when it can be a plus when building the battery and installing the hubmotor and wire.

can you give me hints one wich one would be best? both price are ok for me since i need one hoping it will last me a while

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 21 2022 8:02am
by gobi
A/C at home - I don't ever need a multi meter for A/C work at home,
I use few items, the main one is a tone touch sensor that detects voltage to confirm if the line has power
2nd - a 3 prong plug to test if the outlet is wired right
3rd - a sounder that I can use to trace back to the main panel an outlet to figure out the breaker I need to turn off etc,

I live in a 50s house that was rewired by Motown's finest Electrical Co - Stevie Wonder's Zap Electrical,
:shock:

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 21 2022 10:34am
by Comrade
sharinginfos wrote:
Sep 21 2022 12:42am
the fluke are very expensive
They are relatively more expensive, but total cost of ownership is a thing. Initial price is far from the total cost. How long before you need to replace thin cheap leads? How long do the batteries last? What is the probability of it breaking in a non repairable way divided by how many years to you plan to keep? What is the residual/resale value?

A used quality tool is almost always a much better value (=total cost of ownership) than a cheap tool. If you pay retail on new quality tool it still is often a better value.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 21 2022 8:58pm
by amberwolf
gobi wrote:
Sep 21 2022 8:02am

3rd - a sounder that I can use to trace back to the main panel an outlet to figure out the breaker I need to turn off etc,
I guess that's a few steps up from a bobby pin. ;)

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 22 2022 10:50pm
by sharinginfos
im building a 48 v battery with used vtc4
iwould have to verify with my desing but i think it is a 13 s4 p or 14s 4p(14 most probably.
even though i will only use a xiongda 7amps to begin with i want my battery to be able to be working with higher amps for future upgrade so like 60 amps .
amberwolf wrote:
Sep 21 2022 1:16am
sharinginfos wrote:
Sep 21 2022 12:42am
the whole point of building my own battery is to save money and have good quality cells i bought used from Drbass prepandemic ill use the multimeter to try to put cells with same voltage in paralle.
<snip>
i mentionned that it would be nice that the multimeter can be used in home
Ah, well, since you didn't tell us any of that, we couldn't know to suggest cheaper things. ;)

It would be best if you specified a budget that recommendations should not exceed.

Presumably for your battery build application, it only needs to measure DC voltages up to the max voltage of the battery. What will that be? (how many series cells (groups) will it have?)


Note that if you buy a meter only just capable of this, and need other capabilities later, you'd likely have to spend the same money (and probably more) all over again to get those. But if you never need the other capabilities, it might be a waste of money to spend on them now.

If I had to choose between the two options you linked last, I'd pick the clamp-on meter, as it is only about $7 more than the other, and can do significantly more, including the temperature and high-current measurement options useful for ebike testing. Whether one is really any better than the other, I couldn't say, never having used that "brand".


FWIW, the most commonly used meter modes for ebike troubleshooting are <200 DCVolts, Continuity, 2-20KOhms.

Measuring DCAmps is helpful in various kinds of testing, but usually you'd need to measure 20-30A ranges or higher to be useful; and often only while riding to do the testing under sufficient load--in those cases, a wattmeter is more useful and does more things for the money.

Temperature testing is sometimes useful as well.


AC measurements are almost never needed on ebike testing/troubleshooting, so if a meter doesn't have that function, it's not a big loss unless you think you will use it for household wiring troubleshooting (which I recommend leaving to experienced professionals if you are not yourself experienced at it, unless you first learn enough about it; it's too easy to make a fatal mistake testing or fixing household AC wiring stuff).



sharinginfos wrote:
Sep 19 2022 12:24am
I like to make a good buy when i do a buying
Atm i only need to mesure voltage but maybe tomorow i will need other functions

i dont want to become an expert on multimeter.
i see 3 choices with like 15 doll difference below

wich should i choose?
i never had to use a multimeter and live in an appartement.
<snipped links>
wich one is better for futur application and why
sharinginfos wrote:
Sep 21 2022 12:42am
the fluke are very expensive. the whole point of building my own battery is to save money and have good quality cells i bought used from Drbass prepandemic ill use the multimeter to try to put cells with same voltage in paralle. yes using a cadillac is fun but do i really need that to check the cells and stuff?
i mentionned that it would be nice that the multimeter can be used in home but i never had to use one so far and dont know exacty what feature are needed. Im not going to specialise in electricity battery building after i will have build a safe and fonctionnal battery wich is my goal

what i understand from your writing is tha no1 link has to many options , the no3 is not up to the task

So i guess i have to choose between the no2 and the clamp on
<snipped links>
I did not know that clamp multimeter existed. not sure when it can be a plus when building the battery and installing the hubmotor and wire.

can you give me hints one wich one would be best? both price are ok for me since i need one hoping it will last me a while

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 22 2022 11:40pm
by docw009
I find that an inexpensive multimeter is sufficient for my ebike work, even for testing internal cells on batteries. I have several of the free Harbor Freight meters and a more expensive $20 model. Used to have a Hewlett Packard, but it died.

An RC wattmeter is useful if you're testing batteries. These things are horribly uncalibrated, but once you compare it against an accurate source, it's handy to see what kind of currents are flowing. Also measures peak amps, voltage droop.

https://www.ebay.co.uk/itm/234473396262 ... R571lIntYA

If you're trying to recover cells to build batteries, don't bother. But if you insist, then you probably need a capacity tester to find out how many mah is in that cell. I have a Littokala 500S, but the 500 is cheaper. You might have to ask around to see it it's worth paying for the 500S.
https://www.ebay.co.uk/itm/304576258390 ... BM2pbDie1g

And knowing that the used cells you bought really are 2400 mah isn't enough to tell you that they will work for an ebioke. Your need a series reistance tester like the YR-1035. This is really precise. You can read your cells down to 41.717, or three decimal places.
https://www.ebay.co.uk/itm/195066159044 ... BM_NH7ie1g

It's an endless rabbit hole. I think a good way to get low cost ebike batteries is to buy used packs from a failed scooter/ebike rental company. Quite a few of those in the USA. I've picked up 36V 10AH packs for $25USD that work well, and they are rugged.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 23 2022 1:05am
by calab
The average punk like me and you, dont need no fancy smansy Fluke meter, at most a $25 meter, if your feeling Big & Rich then say $35, or $40. If you want to flex, buy a used Fluke.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 23 2022 1:06am
by Overclocker
best combination is an ultracompact "card" type dmm w/ fixed leads so you don't accidentally leave it in the 10A socket :lol:

plus a DC clamp meter. make sure it's DC, cheaper ones can only measure AC

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 23 2022 2:34pm
by gobi
amberwolf wrote:
Sep 21 2022 8:58pm
gobi wrote:
Sep 21 2022 8:02am

3rd - a sounder that I can use to trace back to the main panel an outlet to figure out the breaker I need to turn off etc,
I guess that's a few steps up from a bobby pin. ;)
lol, finding the breaker for an outlet is a game of chance!

Op, watch some home electrical repair/upgrade videos and see that tools they use. It is VERY hard to use the test leads when you are on your knees and little chunky like moi.

Re: what multimetre should i choose for present cell mesurement and future home task

Posted: Sep 23 2022 2:50pm
by nicobie
I agree with AW that a cheap DMM like the one Harbor Freight used to give away is good enough for ebike and home use. That said, I also own a nice Fluke 89 for when I absolutely must have a spot on measurement (which is exceedingly rare).

For me the most important features are;

Auto off
beeps when testing for continuity
good silicone lead wires
clear & large enough display