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battery for volt meter

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itaishi

New Member
my new 220v AC meter display stopped working.
my guess is that it is a battery that got empty.

1. how can i now if it rechargeable (i guess not)
2. why a device that is connected to 220VAC cant function without been depended on the battery.
3. how can i solder this battery like it is now? (stright to the battery)


this is the device:
http://www.terapeak.com/worth/eu-pl...er-lcd-monitor-advanced-ammeter/231055360826/
 

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Les Jones

Well-Known Member
Most Helpful Member
The battery is a rechargable one. It is charged while the device is plugged into the mains and is should keep the display powered for several hours (or maybe even several days.) if the power is removed. If it has not been plugged into the mains for a long time the battery will discharge. Plug it into power an leave it for a few hours for the battery to charge. If the display does not come on after a few hours try pressing the reset button. If that fails i suggest returning it as faulty.

Les.
 

itaishi

New Member
The battery is a rechargable one. It is charged while the device is plugged into the mains and is should keep the display powered for several hours (or maybe even several days.) if the power is removed. If it has not been plugged into the mains for a long time the battery will discharge. Plug it into power an leave it for a few hours for the battery to charge. If the display does not come on after a few hours try pressing the reset button. If that fails i suggest returning it as faulty.

Les.
i already have no warrenty,
it was almost a year not in use.
after couple of hours , still it not start up.
i need to check the battery, any suggestsion how to check it?

i found where to buy a new one if needed:
http://www.ebay.com/itm/3x-Ni-MH-Bu...20MAH-For-PLC-Data-backup-power-/320862847468

or this:
(is it true i can use 80mAh instead of 20mAh with no worries?)
http://www.ebay.com/itm/3-x-Ni-MH-8...hash=item2c87d4911f:m:mLtb-oY6ihAvI1Pam_Bi0Xw
 
Last edited:

chemelec

Well-Known Member
Do you have a Multimeter to see if the battery is Holding Or Getting a Charge of any Kind
 

AnalogKid

Well-Known Member
Most Helpful Member
1. Unplug the unit from the mains.
2. Measure the battery voltage with a DC meter.
3. Plug the unit into the mains for 4 hours.
4. Unplug the unit and measure the battery voltage again. Let us know what you find out.

It could be a circuit failure of a battery failure. Most rechargeable batteries do not like being unpowered for such a long time.

ak
 

ericgibbs

Well-Known Member
Most Helpful Member
Most rechargeable batteries do not like being unpowered for such a long time.
This is also what I found happened on a couple of mains pluggable power indicators, the battery will not recover.
E
 

alec_t

Well-Known Member
Most Helpful Member
after couple of hours , still it not start up.
According to the battery label, it needs to charge for 14 hours (at 2mA) to reach full charge. But as others have said, after such a long time discharged it may be dead.
 

audioguru

Well-Known Member
Most Helpful Member
The battery is Ni-MH and it might have the old technology that lost its charge in a couple if months so were no good for a flashlight that lives in a car or in a drawer. New technology Ni-MH cells hold a charge for one year but not all of them (a (9V Ni-MH battery still has the old technology).
 

itaishi

New Member
ok guys,
i made this check:

1. i pull out the battery from the PCB, and check the voltage : 1.27 Vdc
2. now get it back (soldering it back) and also soldered 2 wires from the battery outside the device, s i can measure its voltage when it is connected to 220VAC.
(you can see it in the photos attached)

3. the Volt Meter show that the voltage raise up till 1.6 Vdc and than stopped.
even after 3 hours - in 1.6Vdc the voltage stopped raising up.

(not sure if it have somthing with the bad soldering all over the PCB - this is how it cames)

1.6V is not a voltage of a Zener Diode?
i guess two more things i can do is buying another battery or trying charge this battery outside with other charger...
any more suggestions ?

thanks,
itai.
 

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audioguru

Well-Known Member
Most Helpful Member
The battery in your meter is labelled "3.6V" so since it charges to only 1.6V then either the battery is defective or the charger is defective. The battery should charge to about 4.2V.
The meter should be turned off for the battery to charge.
 

itaishi

New Member
The battery in your meter is labelled "3.6V" so since it charges to only 1.6V then either the battery is defective or the charger is defective. The battery should charge to about 4.2V.
The meter should be turned off for the battery to charge.
I also disconnected the multimeter from the battery (wires were disconnected from the multimeter for about 3 hours)
And still same results.
1.6vdc on the battery
 

Les Jones

Well-Known Member
Most Helpful Member
The battery is made up of 3 cells. Two of the cells have gone short circuit. You MAY get it back to life by pulsing a fairly large current though it. You could use a 4.8 volt NiMh battery or a 6 volt lead acid battery . DO NOT CONNECT IT FOR MORE THAN ABOUT ONE SECOND. (It could explode if you do.) Even if this works it will probably fail again in a short time. The battery needs to be replaced. This is a link to a battery that would probably fit.

Les.
 

itaishi

New Member
The battery is made up of 3 cells. Two of the cells have gone short circuit. You MAY get it back to life by pulsing a fairly large current though it. You could use a 4.8 volt NiMh battery or a 6 volt lead acid battery . DO NOT CONNECT IT FOR MORE THAN ABOUT ONE SECOND. (It could explode if you do.) Even if this works it will probably fail again in a short time. The battery needs to be replaced. This is a link to a battery that would probably fit.

Les.
will it be safe to get out the battery,
than plug the device to 220VAC (without the battery)
and than check to see how much voltage there is on the battery place (with no battery),
it suppose to be around 4Vdc ?

could a process like this harm the device?

thanks.
 

audioguru

Well-Known Member
Most Helpful Member
Probably you should not power the meter from 220VAC with the battery removed because maybe the battery keeps the voltage from exceeding about 4.2V.
 

itaishi

New Member
Probably you should not power the meter from 220VAC with the battery removed because maybe the battery keeps the voltage from exceeding about 4.2V.
i didnt understand clearly what you meant....
if the battery keeps the voltage from exceeding about 4.2V - so its for sure a faulty battery....
if i would do a test like this - it will help me figure it out.

my question was clearly?
i asked if the device could be broken/harm if i would plug the device to 220VAC without the battery inside.
my intoitive thinking is that nothing can happen,
but you guys know much more than i do.

thanks.
 

audioguru

Well-Known Member
Most Helpful Member
Your battery has three Ni-MH cells in series. An old Ni-Cad battery had the problem of becoming shorted but a modern Ni-MH battery should not have this problem. All my Ni-Cad batteries became shorted but none of my many Ni-MH batteries.
We do not know if your battery is defective or if the charger circuit is defective.

The charger might simply be a resistor to limit the charging current and the battery keeps the voltage given to the meter from exceeding about 4.2V. Without the battery if you power the meter from 200VAC then the voltage to the meter circuit might be high enough to damage it so Dont Doo EEt!
 

Les Jones

Well-Known Member
Most Helpful Member
I agree with ag. If you are not going to fit a new battery then connecting a 3.9 volt zener diode in place of the battery whould prevent the voltage going too high. It looks like there is quite a lot of space inside the case so you may be able to use a different battery. I have had plug in digital timers go faulty due to a faulty NiMh cell. I have found the cheapest source of thes single cells to buy solar garden lights from one of the pound shop chains and remove the cell from them. As your battery consists of three cells you would have to get three of these.

Les.
 

itaishi

New Member
Your battery has three Ni-MH cells in series. An old Ni-Cad battery had the problem of becoming shorted but a modern Ni-MH battery should not have this problem. All my Ni-Cad batteries became shorted but none of my many Ni-MH batteries.
We do not know if your battery is defective or if the charger circuit is defective.

The charger might simply be a resistor to limit the charging current and the battery keeps the voltage given to the meter from exceeding about 4.2V. Without the battery if you power the meter from 200VAC then the voltage to the meter circuit might be high enough to damage it so Dont Doo EEt!
geee an answer of an expert !!!
thanks alot !!
:)

so we go back to the only 2 choices:
1. buy a battery and check.
2. trying to charge the batteris outside the device - a little bit dangarous as i understood....
 

alec_t

Well-Known Member
Most Helpful Member
I have found the cheapest source of thes single cells to buy solar garden lights from one of the pound shop chains and remove the cell from them.
Cheap yes, but durable/reliable?? Don't think AG would agree :).
 
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