Multimeter Advice For Li-Ion Batteries

[Mark617]

First of all, hello! Long time reader. You guys have cost me a lot of money

I am in the process of volunteering here in northern CA for this upcoming summer (SAR type work with the Forestry Service) and one thing I will need is a flashlight. Most of the flashlights I have been recommended require Li-Ion type batteries (18650 size).

I am being overly paranoid about their use / safety - admitted, but one thing they have mentioned in terms of safe handling is keeping an eye on voltage and some of the other metrics. Thus, I need a DMM for that purpose - specifically.

That does not mean I am ruling out a meter's use for other electrical things, but I need a recommendation on a good DMM for specifically the purpose of testing and maintaining Li-Ion batteries.

Most of the threads here name, obviously, Fluke meters. I would not be here if I didn't subscribe to the adage of "buy once, cry once." That being said, I do not want to invest in a $400 meter if that's overkill (and by all accounts - for my purposes - that is WAY overkill).

So, can I get some advice on the proper meter to get, as well as any information on what functions I need in the meter itself (true RMS etc.)?

Thanks

 

[tapered-pin]

True RMS is a measurement for alternating current, not direct current as found in batteries.

Really, any multimeter will work for something like measuring battery voltage. (and just about all the entry level commercial ones found at HD/Lowes will work for anything any consumer needs on a regular basis)

no real reason to "keep an eye on" the voltage of those 18650 batteries, just keep a couple on hand as replacements.

mine are all made in china rechargeable and they'll power my fenix lights exactly as they should.

good luck, be safe.

 

[rlitman]

If your light only uses one 18650 cell, and if you stick to protected cells, and use a decent charger, you shouldn't have any worries. My charger has a display that shows the cell voltage.

Now, if you have a light that uses multiple cells, or a hokey charger that has some time limits for how long you should charge, or use cheaper unprotected cells in a device not made for them, then you can run into trouble. BUT, owning a multimeter won't be any help with this.

 

[Mark617]

If your light only uses one 18650 cell, and if you stick to protected cells, and use a decent charger, you shouldn't have any worries. My charger has a display that shows the cell voltage.

Now, if you have a light that uses multiple cells, or a hokey charger that has some time limits for how long you should charge, or use cheaper unprotected cells in a device not made for them, then you can run into trouble. BUT, owning a multimeter won't be any help with this.

I would more than likely be using a light with 2x18650s. I know the standard position is use the same cells, same charge, same age, etc. I will be using protected batteries.

One thing re the charger though, even investing in a good one does not guarantee me a max 4.2v charge (say, if it is defective), and this was one area of concern.

But, if as noted above, even a basic DMM from the local HD store will suffice, I can go that route. I just don't want to throw $20 down if spending $100 only one time gets me a product that is more durable, more accurate, has more functions etc., and would make more sense in the long run.

 

[redmondjp]

Get yourself a high-quality battery charger and you won't need a DMM - here are a couple, and I know there are much better ones out there as well; they will tell you everything you would ever want to know about the battery (voltage, ah capacity, etc) and can also maintain and condition the batteries as well.

https://www.amazon.com/dp/B00KW2ZDJO/?tag=atomicindus08-20

https://www.amazon.com/dp/B075JCB9DW/?tag=atomicindus08-20

 

[rlitman]

But how is that multimeter going to protect you against over or under charge?
Will you be holding it against the batteries during the entire charge and discharge durations, and watching the display? Of course not. In the end, you only have the safety devices built into your charger, cells and light to protect you.

Get yourself a high-quality battery charger and you won't need a DMM - here is one, and I know there are much better ones out there that will tell you everything you would ever want to know about the battery (voltage, ah capacity, etc) and can also maintain and condition the batteries as well.

https://www.amazon.com/dp/B00KW2ZDJO/?tag=atomicindus08-20

As a matter of fact, that's the exact one I use.

 

[Mark617]

Fair points.

Thanks

 

[6PTsocket]

First of all, hello! Long time reader. You guys have cost me a lot of money

I am in the process of volunteering here in northern CA for this upcoming summer (SAR type work with the Forestry Service) and one thing I will need is a flashlight. Most of the flashlights I have been recommended require Li-Ion type batteries (18650 size).

I am being overly paranoid about their use / safety - admitted, but one thing they have mentioned in terms of safe handling is keeping an eye on voltage and some of the other metrics. Thus, I need a DMM for that purpose - specifically.

That does not mean I am ruling out a meter's use for other electrical things, but I need a recommendation on a good DMM for specifically the purpose of testing and maintaining Li-Ion batteries.

Most of the threads here name, obviously, Fluke meters. I would not be here if I didn't subscribe to the adage of "buy once, cry once." That being said, I do not want to invest in a $400 meter if that's overkill (and by all accounts - for my purposes - that is WAY overkill).

So, can I get some advice on the proper meter to get, as well as any information on what functions I need in the meter itself (true RMS etc.)?

Thanks [emoji106]

If you are using 18650's you should own a good smart charger that is made to charge them. It will deal with issues like overcharging. They would not have become as common as they are if a DMM was required to maintain them. Some 18650's are "protected" and contain circuitry to handle over charge and over discharge circuitry and can be charged by a simple "dumb" charger. They are also physically longer so they are not interchangable. For advice contact a place like Battery Junction that carries practically every good flashlight made and a big selection oof 18650 batteries and chargers. Get set up with a good working combination and forget about buying a DMM for flashlight maintanence. There are people here that will send you out to buy a Fluke, no matter what your needs. They are related to the people that reccomend Snap On to to the most casual tool user.

Sent from my SM-G900V using Tapatalk

 

[greyeyezz]

https://www.ztsinc.com/minimbt.html

 

[mmason7764]

Mark,

I, like you, am concerned about Lion safety. Made my purchase about 5 years ago, so things have advanced since then. I bought a light that uses CR123 size batteries, and bought rechargeable LiFePO batteries. Lithium Iron Phosphate chemistry does not have quite the energy density of the 3.7 volt cells but is much less prone to overheating and fire.

Don't know what I'd do if shopping today. Last year on garage journal a flashlight discussion mentioned the D cell Mag Lights that are high lumins with LED. Went out and got a silver one just because I couldn't resist. It's the 'garage journal effect'.

Mark

 

[theoldwizard1]

If you are buying your own 18650 cells, buy name brand: Pansonic/Sanyo, LG or Sony are the top suppliers. (Tesla cars use batteries designed by Panasonic.) There are some very good prices on eBay.

Remote Controlled cars and airplanes have been using Li Ion batteries for many years. Consequently they have some of the BEST chargers on the market. A very popular one is the SKYRC iMAX B6. Not cheap, but it will "balance" charger just about anything.

I, like you, am concerned about Lion safety. Made my purchase about 5 years ago, so things have advanced since then. I bought ... rechargeable LiFePO batteries. Lithium Iron Phosphate chemistry does not have quite the energy density of the 3.7 volt cells but is much less prone to overheating and fire.

True about the fire safety, but they have a different nominal voltage (3.2V instead of 3.7V) and different charging profiles (The iMAX B6 can handle both and other battery chemistry as well.) As mentioned they have lower capacity.

You can but a LiCo battery with builtin charge/discharge protection, but they are physically longer.

Depending on their use, you may want/need "high discharge" rate LiCo batteries. The newest high power M18 battery packs use LG batteries.

 

[theoldwizard1]

As for meters, there a lot of GOOD meters in the $20-$50 range. No they aren't as good as the FLukes but they are MORE THAN ADEQUATE for the average DIY. Get something that has a rubber outer guard. If you can find one with a front cover, even netter.

 

[Spacey_G]

But how is that multimeter going to protect you against over or under charge?
Will you be holding it against the batteries during the entire charge and discharge durations, and watching the display? Of course not. In the end, you only have the safety devices built into your charger, cells and light to protect you.

Attempting to charge a battery that's over-discharged is dangerous. If OP is using unprotected cells, the multimeter provides value in screening for over-discharge before attempting a charge. It's also useful to validate that the charger is not overcharging, although that becomes less important once you see that it's doing that reliably.

 

[blkSRT]

Here are suggestions for a charger and batteries

https://www.amazon.com/dp/B01852TBOU/?tag=atomicindus08-20

https://www.amazon.com/dp/B0193UPEWG/?tag=atomicindus08-20

 

[Mark617]

Here are suggestions for a charger and batteries

https://www.amazon.com/Opus-BT-Intel...+charger&psc=1

https://www.amazon.com/ORBTRONIC-PRO...rbtronic+18650

Those batteries were one of two I was looking at. I was also considering the KeepPower wrapped Sanyo batteries: https://www.illumn.com/18650-keeppower-3500mah-sanyo-ncr18650ga-protected-button-top.html

As for the charger, it seems the Nitecore D2 is perfect for me, though I know the Opus 3100 is solid also.

Attempting to charge a battery that's over-discharged is dangerous. If OP is using unprotected cells, the multimeter provides value in screening for over-discharge before attempting a charge. It's also useful to validate that the charger is not overcharging, although that becomes less important once you see that it's doing that reliably.

This pretty much sums up my concerns. I simply figured having an extra set of "eyes," aka redundancy, would be handy until I am more comfortable with the cells, and know my charger and or cells are not acting wonky

 

[upgrading]

I am looking at the D2 for my vaping batts.
Use the link on the right and buy from Amazon for $16.??
I just put that on my list today.

 

[rlitman]

Link for a $16 D2?

 

[upgrading]

https://www.amazon.com/dp/B00KW2ZDJO/?tag=atomicindus08-20

Its there.
Use Amazon on the right though where it say other sellers on Amazon.

 

[IUEC Medic]

Just get Panasonic protected cells and a good quality charger. Every li-ion battery pack for every major cordless tool brand (Milwaukee/makita/dewalt etc) as well as many other propriety batteries are based on protected 18650’s... generally wired in series parallel but sometimes just slightly modified (stream light has been using “proprietary” modified 18650’s for a long time.... )

Tesla battery packs are literally thousands of Panasonic 18650’s wired in series parallel.

The safety issues associated with 18650’s have been on the rise due to cheap manufactured UNPROTECTED cells that are commonly found in vaporizer pens... and the fact that vaporizers work by routing a dead-short through a coil... right in front of someone’s face... sometimes they blow up.

Protected cell, good charger, and proper handling and storage - nothing to worry about.



Any flashlight that uses 18650 cells and is good quality will have a warranty... that warranty will be voided if you use unprotected cells. There’s no reason to use anything but protected cells in a flashlight.

 

[theoldwizard1]

Just get Panasonic protected cells and a good quality charger. Every li-ion battery pack for every major cordless tool brand (Milwaukee/makita/dewalt etc) as well as many other propriety batteries are based on protected 18650’s...

They are NOT individually protected cells ! There is a "smart" charge/discharge controller chip that protects the cells.

Individually protected cells are a waste of money when there are so many good charge/discharge multi-cell controller chips available for very little money !

 

[IUEC Medic]

They are NOT individually protected cells ! There is a "smart" charge/discharge controller chip that protects the cells.

Individually protected cells are a waste of money when there are so many good charge/discharge multi-cell controller chips available for very little money !

Noted, but for his purpose, individually protected cells are ideal.

 

[Crazyjake8493]

A basic multimeter will work for that purpose, you really don't need anything fancy and especially nothing with true RMS. If you're looking to get a clamp meter, I would definitely look for one with true RMS.

 

[SuzukiGS750EZ]

Buy quality batteries and a quality charger and you have nothing to worry about. All my lights take 18650 and I've not had an issue. Non protected cells or cheapies cause issues but if you're relying on a light you shouldn't go cheap anyways. Look on the zebralight website for cells and a charger, I highly recommend the ones listed on there and they aren't expensive (but not "cheap")