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Battery compatibilty

A simple query from a simpleton...

I have a cordless house phone, whose internal batteries are worn out.
They are feeble 700mAh NiCads who hold their charge for only a few
minutes' use now. Can I replace them with some 2100mAh Ni-MH's, of
which I have loads (Recommended charge 7H 420mA)? Or will they not
charge properly on the phone's base unit (Claimed output 9V 300mA)?
And if not, should I just replace them with exact equivalent NiCads?

Thanks in advance.
 
J

Jim Land

Jan 1, 1970
0
[email protected] wrote in 8g2000cwh.googlegroups.com:
I have a cordless house phone, whose internal batteries are worn out.
They are feeble 700mAh NiCads who hold their charge for only a few
minutes' use now. Can I replace them with some 2100mAh Ni-MH's, of
which I have loads (Recommended charge 7H 420mA)? Or will they not
charge properly on the phone's base unit (Claimed output 9V 300mA)?
And if not, should I just replace them with exact equivalent NiCads?

Brand and model of the phone?
 
H

Homer J Simpson

Jan 1, 1970
0
I have a cordless house phone, whose internal batteries are worn out.
They are feeble 700mAh NiCads who hold their charge for only a few
minutes' use now. Can I replace them with some 2100mAh Ni-MH's, of
which I have loads

If they fit, sure.
 
R

Rob Mills

Jan 1, 1970
0
I find them at discount/closeout stores that have odd ball connectors on
them. I cut off the connectors, splice my connector on and have a $2
replacement that's better than the original. RM~
 
K

Ken Weitzel

Jan 1, 1970
0
Homer said:
If they fit, sure.

Hi Homer...

Oops, I'd like to respectfully throw in a caveat here, if I may?

If the phones charging contacts are at all exposed, then make durn
sure that there's a rectifier *inside* the phone to limit current.
Or, failing that, perhaps a very small resistor in series with the
charging contacts.

Otherwise something external shorting them could produce horrible
results. I'm thinking of putting the phone in a pocket with keys
or loose change; or the youngsters tampering with it.

I'd also add that if the op goes this route that he seal the battery
cover up somehow so that the kids can't "borrow" the batteries for
their toys.

I admit to being a little prejudiced; I still have a five year old
scar on my leg from one 1800 mah cell shorting in my pant pocket.

Take care.

Ken
 
K

Ken Weitzel

Jan 1, 1970
0
Homer said:
Resistor?

Hi...

Sure, just a few ohms in series with the batteries would have virtually
no effect while charging, but would severely limit current if they
were inadvertently shorted?

Take care.

Ken
 
H

Homer J Simpson

Jan 1, 1970
0
Hi...

Sure, just a few ohms in series with the batteries would have virtually
no effect while charging, but would severely limit current if they
were inadvertently shorted?

"rectifier" confused me.
 
K

Ken Weitzel

Jan 1, 1970
0
Homer said:
"rectifier" confused me.

Hi Homer...

Now I'm getting confused - not at all unusual :)

A rectifier in series with the battery pack so that it could charge from
the external supply, but not discharge through the external charging
contacts :)


Take care.

Ken
 
E

Eeyore

Jan 1, 1970
0
A simple query from a simpleton...

I have a cordless house phone, whose internal batteries are worn out.
They are feeble 700mAh NiCads who hold their charge for only a few
minutes' use now. Can I replace them with some 2100mAh Ni-MH's, of
which I have loads (Recommended charge 7H 420mA)? Or will they not
charge properly on the phone's base unit (Claimed output 9V 300mA)?
And if not, should I just replace them with exact equivalent NiCads?

I'd use those 2100mAh jobs and give them a whirl. I can't think of any way
you'll damage anything.

Graham
 
H

Homer J Simpson

Jan 1, 1970
0
Now I'm getting confused - not at all unusual :)

A rectifier in series with the battery pack so that it could charge from
the external supply, but not discharge through the external charging
contacts :)

I have phones that can charge face up or face down.
 
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