Battery Tester - Save Some Money

[hoodat]

I'm talking about one of the little cheap multi-battery testers that will check AAA's on up to D cells. Mine will also do the 9V transistor batteries, and little button cell types. Probably cost me five or ten bucks.

Where this thing saves me money is on the stuff that takes two or more batteries, I've noticed that when the light or whatever goes dim, it is usually because of just ONE battery. The other one or even several sometimes, have a bunch of life left. Instead of throwing out a bunch of good batteries, I'm able to detect the bad one and replace it.

Batteries are cheap crap these days, and even among brand new ones, we've had dead ones right out of the box -- especially with the big bulk packs that I usually get.

I noticed this most dramatically when we got a battery powered pepper grinder that uses six AAA's. With fresh cells, it grinds like a meat grinder -- then a few weeks or months later, it ain't got enough poop to pepper an egg.

I learned that if I check all six, it's usually just one or maybe two that read down in the "replace" zone. When I replace them, we're good to go for a good long while.


This kind of makes me wonder if the batteries on these electrified cars will be much different. I've heard that their power cells are composed of a bazillion smaller batteries. jd

[Mal Paso]

That goes against Manufacturer's Recommendations. You should replace them all!

And yes, the car batteries are designed to lose a few cells and keep on going. On Teslas the cells are indiidually fused.

[Winger Ed.]

This kind of makes me wonder if the batteries on these electrified cars will be much different. I've heard that their power cells are composed of a bazillion smaller batteries. jd

Yeah. You'd need to bring a sandwich and something to drink--
Finding which one went bad could take awhile.

[rancher1913]

anytime you have multiple batteries in a system, be it a flashlight or car, always replace all the batteries at the same time. a weak but still good battery will ruin a new battery when placed together. you can use the old but good batteries together in a system but dont mix new and used.

[elmacgyver0]

Alkaline batteries will lose density as they discharge.
If you drop a new battery on a piece of steel or marble countertop, it will just go thud and not bounce.
A discharged cell will bounce.
Kind of the difference between dropping a lead BB and a steel BB on an anvil.
Try it, you will soon be able to judge the charge of a battery by the sound it makes bouncing on a very hard surface.
Oh, you need to drop it on the end.

[georgerkahn]

anytime you have multiple batteries in a system, be it a flashlight or car, always replace all the batteries at the same time. a weak but still good battery will ruin a new battery when placed together. you can use the old but good batteries together in a system but dont mix new and used.

I "hear" what you're saying, and it may very well be the case with plain-Jane batteries, and Alkalines, and Lithium. However, I have LED ceiling lights in RV Trailer (our "camp") which employ four AA cells as their power source. I've used small battery-level tester for years, and generally one or two seem to discharge at a much greater rate than the other two. (They're in a circle coinciding with perimeter of fixture, so I do not know which "order" they might be in?)
Anyhoos -- I've been using (el cheapo) NiMh AA cells (Amazon.com), and remove all four cells. I simply replace the two almost depleted ones with two fully charged ones fresh from the solar charger -- and, doing this, they have performed well for going on four years!
Perhaps using NiMh, or maybe (?) other rechargeable batteries is an exception to, "always replace all the batteries at the same time"?
I do not know the answer... just posting a comment on what has worked well for me.
geo

[Noah Zark]

^^^ I'm with geo.

Anything in the house that uses AAA, AA, C, or D cells uses NiMH rechargeables and for several years now. Flashlights, Brother label maker, clocks, electric toothbrushes, digital SLR cameras, guitar tuner, firearm optics, whatnot. I write a yy-mo-# code on each battery to track their performance and service life. The last ones I bought I marked 20-12-1 thru -4, for example. The earliest ones are marked 16-02-1 thru -4 and are still going strong. Saved a TON of $$$ on alkalines over 6-1/2 yrs.

Noah

[Dave W.]

Snip

This kind of makes me wonder if the batteries on these electrified cars will be much different. I've heard that their power cells are composed of a bazillion smaller batteries. jd

Yes, batteries in electric and hybrid vehicles are made up of several individual cells. In general, when the difference between the best cell and the worst cell reach a certain point the computer condemns the entire battery assembly, it does not test to see if it is good or bad. Battery re-builders take several battery's apart and test each cell. The cells that match are reassembled and sold as a complete battery. After installation, the computer sees that all the cells match and thinks the battery is good, even it only has half the capacity it should.

This is a very simplified version of a much more complicated process.

[hoodat]

anytime you have multiple batteries in a system, be it a flashlight or car, always replace all the batteries at the same time. a weak but still good battery will ruin a new battery when placed together. you can use the old but good batteries together in a system but dont mix new and used.

Sorry, but I just haven't found this to be the case. What I have found is that in a set of six new batteries, one will often become drastically depleted while five others will show 80 or even 90% remaining charge. And, this seems often to be the case with high end brands as well as low end. Although I have had more duds among the cheap ones, even when fresh from the pack. jd

[JimB..]

I’ve always thought that a no-load test didn’t tell you much since even a nearly depleted battery will produce its stated voltage.

Maybe I’ll write installation dates on them and give this a try. But maybe not, I really don’t want to be disappointed by something not working when I need it two or three times as often as happens now.

[Mal Paso]

I’ve always thought that a no-load test didn’t tell you much since even a nearly depleted battery will produce its stated voltage.

Maybe I’ll write installation dates on them and give this a try. But maybe not, I really don’t want to be disappointed by something not working when I need it two or three times as often as happens now.

The better Battery Testers put a load on the battery while measuring, giving an accurate idea of remaining power. Multimeters generally do not.

Mixing new and old Lead/Acid batteries is a big no no, but they are being recharged as a string as well as discharged. The old batteries will bring the new ones down to their level. I'm not sure that is true of a disposable battery or one that gets recharged independently in a charger.

Some sort of evaluation is necessary to avoid throwing money away. I just had my first DOA Duracell.

[MaryB]

Soon as you turn on a device with 1 new battery and some old batteries the old batteries will discharge the new one down to their level. That is a physics FACT that cannot be violated. Unless you have an expensive battery tester with a load check you are not seeing the real state of the battery.

[Electrod47]

Quote: "I just had my first DOA Duracell."

I have 6 game cameras running, at 8ea I buy a lot of batteries. Always Duracell New. Change all 8 when needs arrive. This year I have had a couple cameras die first week. Started testing with a real OHM meter. I found a few DOA in the package! That's new to me, also.

[JonB_in_Glencoe]

I use the ammeter mode on my DMM to test small batteries (AAA thru D cell).

It's interesting to see some multi battery devices discharge just one battery, while others discharge the group equally.

My HF wireless door bell uses (2) AA batteries, it will discharge one battery almost completely in a month, while the other battery has near full charge.

I have a small 3M "wire label" printer that takes (6) AA batteries, I use rechargeables for this device...the weird thing with it, if I leave the batteries in it for a couple months and even if it sees no use, all six are near completely discharged, so I started removing them inbetween uses, and the batteries are fine for many months. After a certain amount of use, I find two of the six batteries quite low and the other four still have a pretty good charge. I can't imagine why there would be a need to design a label maker to have energy sucking memory?

My cheap Sony radio uses (2) AA batteries, they seem to last forever, even with use...and when the batteries finally get run down, they both measure near zero.

[farmbif]

I'm too cheap to throw away batteries that will still make stuff work. aaa's aa's, c's d's and lantern batteries are one thing but has anyone had to buy car, tractor or heavy equipment battery lately the prices are up so high it costs a small fortune to replace all the batteries in my tractors and other stuff.
thow the used ones in a bag and when the box is empty of new ones test the old ones with multimeter and toss only the ones that are too low. one of the best investments I made in a flashlight was a lithium battery rechargeable from same club a few years ago. whats crazy is as you all know trail cameras are a major investment too and most of em take 8 or 16 aa's it aint cheap keeping them running. looking forward to rechargeable lithium replacement ents for aaa's and aa's

[jonp]

I "hear" what you're saying, and it may very well be the case with plain-Jane batteries, and Alkalines, and Lithium. However, I have LED ceiling lights in RV Trailer (our "camp") which employ four AA cells as their power source. I've used small battery-level tester for years, and generally one or two seem to discharge at a much greater rate than the other two. (They're in a circle coinciding with perimeter of fixture, so I do not know which "order" they might be in?)
Anyhoos -- I've been using (el cheapo) NiMh AA cells (Amazon.com), and remove all four cells. I simply replace the two almost depleted ones with two fully charged ones fresh from the solar charger -- and, doing this, they have performed well for going on four years!
Perhaps using NiMh, or maybe (?) other rechargeable batteries is an exception to, "always replace all the batteries at the same time"?
I do not know the answer... just posting a comment on what has worked well for me.
geo

+1 Done similar for quite some time

[ascast]

I do not rotate my tires either. What a bunch oh whooooiiieeee.

[Mal Paso]

Soon as you turn on a device with 1 new battery and some old batteries the old batteries will discharge the new one down to their level. That is a physics FACT that cannot be violated. Unless you have an expensive battery tester with a load check you are not seeing the real state of the battery.

Yes, but is there a net loss of energy? If they equalize and die at close to the same time, isn't that the goal? If you throw away half used batteries you are losing that energy for sure.

Keeping and sorting half used batteries could get complicated. I've already got a pile of half used Kirkland's I'm finishing off in night lights.

[JimB..]

Yes, but is there a net loss of energy? If they equalize and die at close to the same time, isn't that the goal? If you throw away half used batteries you are losing that energy for sure.

Keeping and sorting half used batteries could get complicated. I've already got a pile of half used Kirkland's I'm finishing off in night lights.

Batteries are a mostly one direction chemical reaction. I think the old batteries get a little lift from the new battery, but the internal resistance is high so the efficiency is low. I think your approach of moving them from high-drain to low-drain applications is going to be more cost effective.

[MaryB]

Yes, but is there a net loss of energy? If they equalize and die at close to the same time, isn't that the goal? If you throw away half used batteries you are losing that energy for sure.

Keeping and sorting half used batteries could get complicated. I've already got a pile of half used Kirkland's I'm finishing off in night lights.

There is ALWAYS a net loss of energy, circuit resistance, battery resistance/chemical state... losses abound!

[MaryB]

Batteries are a mostly one direction chemical reaction. I think the old batteries get a little lift from the new battery, but the internal resistance is high so the efficiency is low. I think your approach of moving them from high-drain to low-drain applications is going to be more cost effective.

I have charged alkaline batteries(I do not recommend this! I am an electronic tech and know how dangerous this is!) as a test... outside in case one exploded! But they will recharge to about 75% of normal life span. Required some careful monitoring of battery temperature to do it.

Growing up I remember putting the old chemistry(1960's era...) batteries in the freezer to make them gain a little more use. Doesn't work on alkaline batteries.

[Land Owner]

When the TV Channel changer runs down, take the batteries out, hold the charger ON for 15 seconds or more, tap the positive pole of the first AA against the negative pole of the other AA about 15 times. Swap the batteries end-to-end and repeat 15 times. Put them back in. Works every time.

The cheapest battery tester, Good==Bad, without a numerical number of the charge is a waste of time and money (imo). Pay $10 more for a digital tester with a readout of the charge. Alkalines with a charge above your designated 'Throw Away' level are kept and the remaining charge is written on the side in fine point marker.

Alkaline flashlight batteries are still 'good' down to about 1.2 V (ymmv) and diminish rapidly thereafter. A single battery can kill the output from a stack. Replace discharged batteries with alkalines that are similar in charge to the 'good ones' and keep going.

My game feeder runs off of a single square 6V alkaline lantern battery. Since there is room, and to reduce costs, I purchased a four pack of rechargeable 6V batteries. Now I run the feeder with 2-at-a-time batteries in parallel through a simple wiring harness that I soldered together, which works great and nearly triples the effective battery life. Then swap the 2-pack out with a recharged 2-pack and keep going.

Rechargeable batteries SAVE A LOT of money. Game cameras and timed feeders are battery hogs. Find a way to cut costs.

[abunaitoo]

I use battery testers all the time.
I remove the batteries from things I don't use everyday.
Stuff like TV remote, clocks, flashlights..... I check the batteries when the item starts acting un-normal.
Replace them with new batteries
On the other stuff, I do mix and mismatch.
But I test them before installing, and remove them when finished.
Any that have less than 1/2 life get thrown away.
I've found if you use good, known brand, batteries, they last longer before they start to leak.

[JimB..]

I have charged alkaline batteries(I do not recommend this! I am an electronic tech and know how dangerous this is!) as a test... outside in case one exploded! But they will recharge to about 75% of normal life span. Required some careful monitoring of battery temperature to do it.

Growing up I remember putting the old chemistry(1960's era...) batteries in the freezer to make them gain a little more use. Doesn't work on alkaline batteries.
I intentionally avoided talking about recharging alkaline batteries because some of these guys are cheap enough to try it and may well burn their house down trying to save a buck.

[MaryB]

I intentionally avoided talking about recharging alkaline batteries because some of these guys are cheap enough to try it and may well burn their house down trying to save a buck.

Why I put in details n procedure. OUTSIDE and constant temp monitoring with an IR gun type thermometer. If it starts into thermal runaway have to be quick on the off button! Or that battery WILL explode.

[BamaNapper]

I have a small 3M "wire label" printer that takes (6) AA batteries, I use rechargeables for this device...the weird thing with it, if I leave the batteries in it for a couple months and even if it sees no use, all six are near completely discharged, so I started removing them inbetween uses, and the batteries are fine for many months. After a certain amount of use, I find two of the six batteries quite low and the other four still have a pretty good charge. I can't imagine why there would be a need to design a label maker to have energy sucking memory?


If this labler consistently does this, I'd assume the voltage across 2 of the batteries is used to monitor the buttons, watching for you to hit the power button when you want to use it. Something with a real power switch actually disconnects the battery, but that little computer inside needs power to to know when you hit a button. I have a kitchen scale that works this way and I find it aggravating. Give it a month sitting in the cupboard and the batteries are dead.