Do these batteries have any life left in them?

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duckDecoy

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#288655 15-Jul-2021 10:55

I have just removed 4 C type energizer max batteries from an eliptical that was claiming to have low battery.

We now know the eliptical is probably faulty, so I want to know if these batteries are actually OK. I know nothing really about batteries or circuits, but I put a multimeter over them and got the following.:

battery1: 1.7A 1.4v

battery2: 2.9A 1.4v

battery3: 2.8A 1.4v

battery4: 2.8A 1.4v

Battery 1 is definitely the outsider. All came from the same packet.

Are these actually OK or should i dispose of them?

Gordy7

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#2744480 15-Jul-2021 11:26

Fresh battery is probably about 1.6v open circuit as measured with a voltmeter. Depending on the application, batteries can be used down to about 1v. If your Elliptical says that your batteries are low then I would replace the whole set.

I am amazed that you have done current test - did you do a short circuit current test with your meter? Not the sort of battery test you would normally do without a current limiting resistor. Your Elliptical probably only draws a few 10s of ma. The current test you did would probably have sucked a lot of energy out of your batteries.

Did you measure that voltage before or after the current test? You would likely measure a different battery voltage depending on the order of your testing.

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

duckDecoy

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#2744534 15-Jul-2021 11:56

Gordy7:

I am amazed that you have done current test -

Whoops. Well I did say I know nothing about batteries or circuits. I guess I now know not to do that lol

Gordy7

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#2744538 15-Jul-2021 12:09

duckDecoy:

Gordy7:

I am amazed that you have done current test -

Whoops. Well I did say I know nothing about batteries or circuits. I guess I now know not to do that lol

As an extreme example... don't try doing a direct current test with a multimeter on a car battery...

At best you will blow a multimeter fuse.... else you may get melted test leads and a blown up multimeter.

Cheers 😀

Gordy

My first ever AM radio network connection was with a 1MHz AM crystal(OA91) radio receiver.

Batman

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#2744559 15-Jul-2021 13:24

wow i learnt something.

i will mark the current test on my MM with a red button saying do not use

Scott3

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#2744566 15-Jul-2021 13:38

Batman:

wow i learnt something.

i will mark the current test on my MM with a red button saying do not use

You can use it, but just don't connect the leads when connected to the current pin's to anything you wouldn't connect up with a piece of wire.

I.e. a circle from a battery, through a load, through the multi meter and back to to the battery would be fine.

tripper1000

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#2744571 15-Jul-2021 13:43

1.4volts is on the low side. Spec is 1.5v but as per above they will be more when new. The thing to remember is that you measured the 1.4v with no load. Once you switch the device on, the voltage will sag lower than 1.4v.

The current reading is used in series with a load to find out how much current the load draws. It is not intended to measure how much current a power source will give (meters that do this are very big, heavy and produce a lot of heat). Your average car battery will supply 500amps and the meter will only measure 10 amps, so the meter/fuse smokes up. A smart modern power supply (eg USB) will detect a short circuit and shut down, preventing you from measuring anything at all.

When I was 10 years old I got my first multi meter and tried to measure the current out of a power point. Much to my surprise and sadness, the Multimeter leapt up off the floor with a bang, a bright flash and a cloud of smoke. (sometimes I wonder how I survived childhood).

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shk292

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#2744594 15-Jul-2021 14:05

tripper1000:

When I was 10 years old I got my first multi meter and tried to measure the current out of a power point. Much to my surprise and sadness, the Multimeter leapt up off the floor with a bang, a bright flash and a cloud of smoke. (sometimes I wonder how I survived childhood).

I'm glad it wasn't just me that tried silly things with electricity as a kid! Eg "what would happen if I put this neon lamp across the terminals of a flash gun capacitor?"

I damaged my dad's avometer in a very similar way, but also managed to repair it with a soldering iron. I think I was the only one who knew

tripper1000

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#2744613 15-Jul-2021 14:48

shk292: I'm glad it wasn't just me that tried silly things with electricity as a kid! Eg "what would happen if I put this neon lamp across the terminals of a flash gun capacitor?"

I was spot welding tin foil by capacitor discharge and got a shock from a large flashgun capacitor from left hand to right hand, across my chest. I just remember pain, massive muscle convulsions in arms and chest, and a blinding white flash in front of my eyes. I learned later that such incidents have killed people and suspect my ticker wouldn't stand up to that kind of abuse now days.

neb

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#2744645 15-Jul-2021 15:12

Gordy7:
As an extreme example... don't try doing a direct current test with a multimeter on a car battery...

At best you will blow a multimeter fuse.... else you may get melted test leads and a blown up multimeter.

More generally, for your typical cheap Chinese-made multimeter never try and put anything close to the rated current through them, everything in them from the leads to the plugs to the current shunt aren't rated at anything close to what the claimed rating is.

1101

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#2745080 16-Jul-2021 10:16

The correct answer is both yes and no.

Those batts are OK for low drain devices
OK for devices that arnt super reliant on full batt voltage
OK if used in parelell
Perhaps OK in series (but will have a greater lower than new voltage)

Not Ok in high drain devices, or in series where voltage is more critical

for example
1.4v per batt Would be OK in old school transistor radios .

Old school Rechargeable C's & AA's were 1.2v . Some devices were OK with that , some wouldnt power up .

neb

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#2745259 16-Jul-2021 17:51

1101: Old school Rechargeable C's & AA's were 1.2v . Some devices were OK with that , some wouldnt power up .

To deal with that if you've got a device with an even number of cells you can use LiFePO4 rechargeables and an empty head to replace a pair of 1.5V cells, So instead of 2 x 1.5V you've got 3.2V + nothing, this is useful for things like NCV detectors which seem to always require 1.5V or close to it and won't run off 1.2V rechargeables.