Author Topic: Battery question please ?  (Read 1935 times)

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Offline Peter3Topic starter

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Battery question please ?
« on: April 29, 2017, 05:59:55 pm »
Hello.
Some years ago my sister and I both purchased remote door bell sets from
our local shops, different manufacturers from different shops. In each case
the main unit was powered by three AA batteries.

Both units failed after a short period and in both cases it was found that the
middle one of the three batteries had discharged to a point that the unit
would no longer function. In addition to this, it was found that in one case
the battery had not only discharged but had also reversed its polarity.

Is there any precedent or known reason for this please?

All on topic replies will be welcomed.
Thank you,    Peter3
 

Offline Kilrah

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Re: Battery question please ?
« Reply #1 on: April 29, 2017, 06:02:39 pm »
Would be interesting to tear it down and see how things are wired.
 

Offline Peter3Topic starter

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Re: Battery question please ?
« Reply #2 on: April 29, 2017, 06:28:53 pm »
Thanks for your reply.
               We junked them shortly afterwards and purchased better quality units but the
question still remains.
Regards  Peter3.
 

Offline Kilrah

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Re: Battery question please ?
« Reply #3 on: April 29, 2017, 06:43:37 pm »
Will be a lot harder to find the reason then...
First thing that comes in mind is that they used only one of the cells for standby power, and the 3 in series only for the gong.

That's terrible design, but I've seen that a few times.
 

Offline Zero999

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Re: Battery question please ?
« Reply #4 on: April 29, 2017, 07:35:35 pm »
If one cell was weaker than the others, then it can discharge and then recharge in the reverse direction, which can cause leaking and mess.

It might be a coincidence or the two doorbells could do as Kilrah said: use one cell for standby, therefore discharge it more than the others.
 

Offline Peter3Topic starter

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Re: Battery question please ?
« Reply #5 on: April 29, 2017, 08:36:29 pm »
Thank you both for your replies.
I see what you mean and it would not surprise me at all if that was the case.
Certainly a very likely explanation.
Thank you  Peter3
 

Offline akis

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Re: Battery question please ?
« Reply #6 on: April 30, 2017, 06:40:32 am »
Hello.
middle one of the three batteries had discharged to a point that the unit
would no longer function. In addition to this, it was found that in one case
the battery had not only discharged but had also reversed its polarity.



Middle battery placed or wired in reverse by accident?
 

Offline Peter3Topic starter

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Re: Battery question please ?
« Reply #7 on: April 30, 2017, 08:39:27 am »
Thank you Akis for your reply.

It is now suggested that the manufacturers of the cheaper units have, in the past,
wired the batteries to use one for the standby then all three to sound the chime.
If so, this would explain why one battery goes down first, resulting in not enough
power to sound the chime.

Thank you again  Peter3
 


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