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

[999zip999]

RMS Wave
Root mean square
upload.wikimedia.org/wikipedia/commons/thumb/8/89/...
RMS Voltage of a Sinusoidal AC Waveform
RMS-Root Mean Square (RMS) The vibration RMS wave definition ...
Measuring the Sine Wave


View all
In mathematics and its applications, the root mean square of a set of numbers x_{i} is defined as the square root of the mean square of the set.
The RMS is also known as the quadratic mean and is a particular case of the generalized mean. Wikipedia
Had to look that up.

 

[sharinginfos]

i do have a bt c3100 opus is that good ? i dont even remember what it is used for. is it to find what milliamps is in there?
what is the cheapest multimeter that i need to figure out the voltage ?
i think the resistance was ok from what i remember from my old testing

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?hash=item3697b41826:g:WJYAAOSwsXRi2PK4&amdata=enc%3AAQAHAAAAoKoXsToCZz5C9Sf7rN4Zwxlx4wtwmkAGydWdejctc%2BgumFpY9%2BVhGZXngvUJixZVUVsaB9aUFth4hxC2fioUbP5%2FZoAEDcEJ76fPEbMTA26M7D6BbmNS2eqxYYL5W1fHJ8d%2BwEsUn7Cw75OurbR4XuyU%2FPDuio7V7spOxtvqSQaCNua%2Fsh%2B7ODA%2FtrLTEOC%2B6CjCZ6n3SfOj08Xw9%2FgiVVQ%3D%7Ctkp%3ABk9SR571lIntYA

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?hash=item46ea28e156:gI0AAOSwJNNi1-Rc&amdata=enc%3AAQAHAAAA4P5HNXx1A2UD1%2FdV4KfgMCoDSj2pvLwcX4F9RnlwTqmOneTyScu2wAWnjYbNsLcs4HCyQtZAHoACjx3cFhNfHptr4Cv27YsjkU%2F0iNXAAHUU%2BmKYynjMfcM8m%2F%2BvzA5VkImuW63dlz3Ywgl7YTJ7qSnzeKPBMjbHvonZVctHVoX6naD3oGt1gmk1Wc3HBvRvRS%2FP1jV%2BtS5W8Y5WliQ%2F57JI5EVC10bHniY5TI%2FGoyLiF%2BUDXS3PDWiB1f3AHwE9cY5y6tS3QVDybnamRAJkvgYQCeK%2FuMYSQpgI55w5zzGL%7Ctkp%3ABFBM2pbDie1g

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?hash=item2d6ad95fc4:g:7UUAAOSwJRBihd66&amdata=enc%3AAQAHAAAA0EjwWqc9OGoStNQW04pbsYLQ7t3zxYvAxsHzPxDsbpRDL66yFIoQ0mf08nEcSeYwn%2FdDaIZBOYYOxf9Pd27shjp%2BHSczBZ9kJBL%2BKDfZ7oCZj1qFqiXoC8SVssk8u1zeLhuB5BC6UW2oFdGS0BPkVEQfsrd%2BSU0mqOBrz0T%2F%2FHNAknDsckksHgNggVYM%2BaIQeuTgV1n3218NNR52m%2FBs60YG%2B3yXslrC180Ug4oqLDV0ofePjlEWwij%2F3b%2BuzNFPcym7aqRdDM74NS7rszeTQi4%3D%7Ctkp%3ABFBM_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.

 

[E-HP]

i do have a bt c3100 opus is that good ? i dont even remember what it is used for. is it to find what milliamps is in there?
what is the cheapest multimeter that i need to figure out the voltage ?
i think the resistance was ok from what i remember from my old testing

Of the three you listed, #3 is definitely the cheapest.

 

[tomjasz]

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

I got one of these due to the number of decimal points, just to calibrate my lipo charger cell voltages. Youtube reviews say it's fairly accurate.
ANENG-AN8008-

A number of decent electronics channels on YouTube have reviewed the auto-off, auto-ranging low-priced Aneng meters. I have a couple. They're small and well within acceptable parameters.

 

[E-HP]

A number of decent electronics channels on YouTube have reviewed the auto-off, auto-ranging low-priced Aneng meters. I have a couple. They're small and well within acceptable parameters.

It's hard to find the resolution that they have in a low priced unit. I use it less for general stuff because it's little and too light, and doesn't stay in one place while I'm trying to measure stuff, but nothing to do with the accuracy, etc.

 

[tomjasz]

:thumb:

 

[docw009]

i do have a bt c3100 opus is that good ? i dont even remember what it is used for. is it to find what milliamps is in there?

If you're working with used cells, it's a very useful tool. It can measure the maH capacity of your cells at different charge/discharge levels. You don't want to mix cells with big differences in capacity. Even with new cells, it doesn't hurt to sample a few,

Also can charge/discharge your cells so you can have them all at the same voltage before you assemble them.

 

[portals]

Do you have Lidl stores where you are?

In UK I bought their Parkside auto-ranging multi meter for £10 (C2 model or latest C3 model), it is phenomenal value for money and functionality/measurements are comparable to the more expensive meters I have. Downside however is the test probes it comes with are rubbish, I use probes from another meter I bought many many years ago that are OK quality. Really there is little need to buy a more expensive meter for the casual user.

 

[tomjasz]

 

[sharinginfos]

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?hash=item3697b41826:g:WJYAAOSwsXRi2PK4&amdata=enc%3AAQAHAAAAoKoXsToCZz5C9Sf7rN4Zwxlx4wtwmkAGydWdejctc%2BgumFpY9%2BVhGZXngvUJixZVUVsaB9aUFth4hxC2fioUbP5%2FZoAEDcEJ76fPEbMTA26M7D6BbmNS2eqxYYL5W1fHJ8d%2BwEsUn7Cw75OurbR4XuyU%2FPDuio7V7spOxtvqSQaCNua%2Fsh%2B7ODA%2FtrLTEOC%2B6CjCZ6n3SfOj08Xw9%2FgiVVQ%3D%7Ctkp%3ABk9SR571lIntYA

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?hash=item46ea28e156:gI0AAOSwJNNi1-Rc&amdata=enc%3AAQAHAAAA4P5HNXx1A2UD1%2FdV4KfgMCoDSj2pvLwcX4F9RnlwTqmOneTyScu2wAWnjYbNsLcs4HCyQtZAHoACjx3cFhNfHptr4Cv27YsjkU%2F0iNXAAHUU%2BmKYynjMfcM8m%2F%2BvzA5VkImuW63dlz3Ywgl7YTJ7qSnzeKPBMjbHvonZVctHVoX6naD3oGt1gmk1Wc3HBvRvRS%2FP1jV%2BtS5W8Y5WliQ%2F57JI5EVC10bHniY5TI%2FGoyLiF%2BUDXS3PDWiB1f3AHwE9cY5y6tS3QVDybnamRAJkvgYQCeK%2FuMYSQpgI55w5zzGL%7Ctkp%3ABFBM2pbDie1g

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?hash=item2d6ad95fc4:g:7UUAAOSwJRBihd66&amdata=enc%3AAQAHAAAA0EjwWqc9OGoStNQW04pbsYLQ7t3zxYvAxsHzPxDsbpRDL66yFIoQ0mf08nEcSeYwn%2FdDaIZBOYYOxf9Pd27shjp%2BHSczBZ9kJBL%2BKDfZ7oCZj1qFqiXoC8SVssk8u1zeLhuB5BC6UW2oFdGS0BPkVEQfsrd%2BSU0mqOBrz0T%2F%2FHNAknDsckksHgNggVYM%2BaIQeuTgV1n3218NNR52m%2FBs60YG%2B3yXslrC180Ug4oqLDV0ofePjlEWwij%2F3b%2BuzNFPcym7aqRdDM74NS7rszeTQi4%3D%7Ctkp%3ABFBM_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.

hi every one
so i reread the answers thanks .
i would go with the clamp on https://www.amazon.com/dp/B07Z398YWF
and i also have a bt c3100 opus
is this all i need to test wich cells are suitable and still good? or do i need another device to test the used cells i already have? does the multimeter in question or bt c3100 opus test for internal resistance and is testing for internal resistance even needed in order to group the cells in parallel?
Remember that i do not wish to make a perfect battery, just something that will work and that is safe.
i chose the vtc4 because they are said to be safe (have a design that add security) i already have them and 4 or 5 years ago when igot them , the seller told me they came from makita and had still a good life ahead.

second questions is is there a tutorial on how to use the bt c3100 opus ? what options to select , what test to do so i can learn before asking questions about that.

Third question, do you think i should open a new topic to handle the next step that is wich cells are still good enough and how to test that or should i continu my journey on this thread? (maybe some stop to read after a while ?

thanks

 

[99t4]

Remember that i do not wish to make a perfect battery, just something that will work and that is safe.

"As long as the pack is built well of known-good good-quality well-matched cells, with reasonable precautions against damage (mechanical or electrical or environmental), and is used reasonably, not abused, not damaged, not used outside it's limitations, it's unlikely to have a problem."
From ES member Amberwolf: https://www.endless-sphere.com/forums/viewtopic.php?p=1735085#p1735086

and i also have a bt c3100 opus
is this all i need to test wich cells are suitable and still good? or do i need another device to test the used cells i already have? does the multimeter in question or bt c3100 opus test for internal resistance and is testing for internal resistance even needed in order to group the cells in parallel?

This recent post is especially appropriate to your question: https://www.endless-sphere.com/forums/viewtopic.php?f=14&t=117887

Third question, do you think i should open a new topic to handle the next step that is wich cells are still good enough and how to test that...

That would be best. :thumb:

 

[sharinginfos]

hi
i lool at amazon page https://www.amazon.ca/s?k=yr1030&crid=1CLNL6WJB4LI&sprefix=yr1030%2Caps%2C79&ref=nb_sb_noss_2
and there seems to be a yr1030 and yr1030+ . do you know what difference does it make? wich should i buy?

is this bms i have a good enough bms? for 13s 4p
https://www.aliexpress.com/item/32888880741.html?spm=a2g0o.order_list.0.0.62161802pPoKFK


i also have this lunacycle charger . is it good enough? and fit my charging requirement for 13s4p sonyvtc4?

 

[999zip999]

Shearinfo if you talking BMS start a new thread maybe in battery section. Are you building your own pack. With spot welder ?

 

[A-DamW]

Sparkfun decent multimeter on sale til Oct14

https://www.sparkfun.com/products/12966

 

[sharinginfos]

Shearinfo if you talking BMS start a new thread maybe in battery section. Are you building your own pack. With spot welder ?

i am building my own . i hope to be able to use nese since spot welding is scary for me . i read a lot about it and dont feel confortable and dont wich to invest in a spot welder for only 2 13 4p battery.
i placed the bms and charger here just to know if i have the right parts as i like to order and then mesure and build

i see 7 topics but not of them are labeled battery... could you point me out in wich section it is for battery questions?
thx

 

[E-HP]

i see 7 topics but not of them are labeled battery... could you point me out in wich section it is for battery questions?
thx

https://endless-sphere.com/forums/viewforum.php?f=14

 

[sharinginfos]

i see 7 topics but not of them are labeled battery... could you point me out in wich section it is for battery questions?
thx

https://endless-sphere.com/forums/viewforum.php?f=14

oh i see now hehe thanks

 

[999zip999]

I bought the nese kit as 14s8p the cells I used were a bit bigger and had to take off the wrapper. Since all are in parallel. This could be done. If in series it could not be done.
I will look up the cells I got and let you know because these are 18650 cells but a little bigger in diameter than most. No BMS.
BAK 18650 20a cell I like high discard cell hoping for lower resistance and longer life.
I had it for 6mos and haven't use it yet.
I had nese make the kit for me.
I only use new cells.

 

[MLAT]

Meter #2 should do what you need. If you do not need to easily measure DC amps then #1 is OK. Never buy a cheap meter like the cheap HF unit. They are junk. You do not need a Fluke meter. Nice to have but too expensive for most of us. I like the Triplett brand meters. They are an American company that makes good meters at reasonable prices and have been in business for a long time.

 

[LewTwo]

I have several meters acquired over the decades. My GoTo DMM is the one I purchased about 30 years ago. It is a 4000 count Mastech M28336 (although I have replaced the leads). My point is that a good general purpose DMM should last a lifetime.