[Deck]

I have two digital multimeters, both are HoldPeak models. One of them when I turn the dial to V without the probes connected will stay at 000.0mV but the other one jumps around from anywhere between 005.0mV to 030.0mV. Is that normal?

Second question, on one of them I decided I wanted to measure amps from a small 12v battery I had for a power supply, with a rating of 4.5Ah. One meter, which can handle a maximum of 10A, I connected the black probe to the negative battery terminal and the red probe to the positive battery terminal. Then the meter started beeping like crazy and shut off in like 2 seconds. Now that A measurement on the dial doesn't work. I'm pretty sure I blew a fuse, but how? If it's rated for 10A shouldn't I be able to test the amps that way, or do I not understand?

Third question, maybe specific to this brand, but there is a nasty chemical smell coming from the flexible plastic shell of both meters. Does anyone know of any way to neutralize or remove it?

 

[bernie963]

hi,

I will pass on 1 and 3.

2--By connecting the meter the way you did you created a dead short across the battery. Hopefully all you did is blow a fuse. The ammeter function requires the meter be placed in series with a load. ie, battery- meter- load-other battery terminal.

Using a voltmeter you place the meter in parallel with the component being tested. You hooked up an amp meter the way a volt meter should be connected.

Check the fuse, if there is one, surely it is blown. Replace it and if it does not solve the problem, check your meter wires. They may have gotten hot and....

Good luck

Bernie

 

[TimPa]

I have two digital multimeters, both are HoldPeak models. One of them when I turn the dial to V without the probes connected will stay at 000.0mV but the other one jumps around from anywhere between 005.0mV to 030.0mV. Is that normal? as long as the display stabilizes when the leads are placed across a potential, it is fine.

Second question, on one of them I decided I wanted to measure amps from a small 12v battery I had for a power supply, with a rating of 4.5Ah. One meter, which can handle a maximum of 10A, I connected the black probe to the negative battery terminal and the red probe to the positive battery terminal. Then the meter started beeping like crazy and shut off in like 2 seconds. Now that A measurement on the dial doesn't work. I'm pretty sure I blew a fuse, but how? If it's rated for 10A shouldn't I be able to test the amps that way, or do I not understand? the meter was the "load" in the described connection, and obviously the battery was able to exceed 10 amps. check inside for a replaceable fuse. often there is a free one in there. is there a lead jack labeled 10a on this meter?

Third question, maybe specific to this brand, but there is a nasty chemical smell coming from the flexible plastic shell of both meters. Does anyone know of any way to neutralize or remove it? enjoy that new meter smell!

.....

 

[ddawg16]

I concur on 2....and will answer 1 & 3

1....yes, that is somewhat normal depending on the brand of meter and the internal impedance of the input ckt.

3.....most likely you have a cheap Chinese model made with cheap plastic and you are smelling the outgassing of the plastic and related components.

Only time will get rid of the smell.

 

[AllanJ]

You never connect the meter probes across battery terminals except to measure voltage!

The ampere-hours rating refers to modest power draws over a period of time. The battery specs should specify the typical power draw for which the battery is intended.

The 4.5 Ah battery should be able to deliver a half ampere for about nine hours or a quarter amp for about 18 hours. It might deliver 1 amp for about 4-1/2 hours. It might deliver 100 amps for 10 seconds, more than enough to burn out the meter.

Too heavy a power draw will cause the battery to overheat. You should be safe if the power draw is not heavy enough to cause a voltage drop of more than three percent from the nominal or published voltage for the battery. (Some kinds of batteries can take a heavier load.)

 

[Deck]

Thanks guys. One other thing I noticed is both have battery testers that draw 25mA, so I tested them with two C batteries. One meter showed both batteries less volts than the other. When I test both batteries on V it shows the same voltage though.

Meter 1 & 2, Battery 1, V: 1.591
Meter 1, Battery 1, IL 25mA: 1.550
Meter 2, Battery 1, IL 25mA: 1.573

Meter 1 & 2, Battery 2, V: 1.491
Meter 1, Battery 2, IL 25mA: 1.441
Meter 2, Battery 2, IL 25mA: 1.464

Is that type of difference normal for a battery testing mode?

 

[dmxtothemax]

I have two digital multimeters, both are HoldPeak models. One of them when I turn the dial to V without the probes connected will stay at 000.0mV but the other one jumps around from anywhere between 005.0mV to 030.0mV. Is that normal?

Second question, on one of them I decided I wanted to measure amps from a small 12v battery I had for a power supply, with a rating of 4.5Ah. One meter, which can handle a maximum of 10A, I connected the black probe to the negative battery terminal and the red probe to the positive battery terminal. Then the meter started beeping like crazy and shut off in like 2 seconds. Now that A measurement on the dial doesn't work. I'm pretty sure I blew a fuse, but how? If it's rated for 10A shouldn't I be able to test the amps that way, or do I not understand?

Third question, maybe specific to this brand, but there is a nasty chemical smell coming from the flexible plastic shell of both meters. Does anyone know of any way to neutralize or remove it?

1 - Normal
but more of a problem with some cheaper meters
it is simply picking up stray radiation
most testers with a high impedance input can do this.

2 - the amp/hour rating is NOT the maximum current the battery can deliver !
it is the maximum recommended current for maximum life from the cell.
it is the safe working load.
Batteries will deliver substancial currents under short circuit conditions
(as you found out)
all be it for a short period.


3 - take it apart.
take out the battery
clean the circuit board with a toothbrush and some good quality dishwashing liquid.
allow it to dry thoroughly before using
leaving it outside will help dry it.
the water wont hurt it, if it is not energized
and allowed to dry properly before use.

:glasses:

 

[AllanJ]

I would be very hesitant about working with wet chemicals or detergents inside the meter. Too easy for some to drip inside and be impossible to sop up.

Much has been said here and there about "phantom voltage" readings due to capacitance between juxtaposed conductors, say within a Romex cable. Turning on the battery testing mode will eliminate or at least drastically reduce such false readings. If there is a significant voltage with battery testing mode on, chances are that is not phantom voltage and wiring errors or defects need to be checked for.

 

[Oso954]

2 - the amp/hour rating is NOT the maximum current the battery can deliver !
it is the maximum recommended current for maximum life from the cell.
it is the safe working load.

That is not correct.

The amp hour rating is not a current rating, but a unit of measurement of battery storage capacity.

With most batteries the rating is based on 20 hours. So a 100 amp hour battery would have a max current of 5 amps to delivery the 100 amp hours.

Operating at amperage draws above the 20 hr rate, the battery will deliver less than the 100 amp hours. See Peukert's law.

 

[bernie963]

Deck,

Did you find a blown fuse? after replacement is the meter working? If not there is other damage.

The 10 or 20 amp setting is generally unfused. If meter is not working the damage may be permanent.


What brands and model # are these meters?

Bernie

 

[Deck]

Did you find a blown fuse? after replacement is the meter working? If not there is other damage.

The 10 or 20 amp setting is generally unfused. If meter is not working the damage may be permanent.

What brands and model # are these meters?

I haven't opened the meter yet to find out if the fuse has blown but I assume that was it. The meters I have are HoldPeak HP-90B and HP-90EPC and the one that the 10A measurement no longer works on is HP-90B.

3 - take it apart.
take out the battery
clean the circuit board with a toothbrush and some good quality dishwashing liquid.
allow it to dry thoroughly before using
leaving it outside will help dry it.
the water wont hurt it, if it is not energized
and allowed to dry properly before use.

The chemical smell is coming from a flexible blue rubber shell surrounding the meters. The shells appear to be removable. I was thinking if there was something I could use to neutralize the smell or even soak it in. It's a poisonous chemical smell that gets absorbed in my hands. I don't know that it is poison but I mean it sure smells like it.

 

[AllanJ]

If the meter probe ends and/or the things you are touching the probes to are not clean then you can get jittery readings. Some meters have needle sharp probe ends that will make a good connection faster with a small amount of pressure.

If you want to, you could remove the blue shell and set that aside.

Advantages: Meter is less bulky to handle. No more smell.

Disadvantages: Meter more susceptible to damage if dropped. May pose an electrocution hazard when used for voltages near its maximum capability.

With most batteries the (ampere-hours) rating is based on 20 hours.

Thanks.