Battery Condition Test - how can I tell if the battery I bought is good ?

[Vadim Bishtein]

I bought a 9V Lithium cell primary battery (single use battery, not Li-Ion
rechargable like in cellphones).
I suspect it might be old or not in good condition. To test it I hooked it
to 500 Ohm resistor and measured
the output voltage:
No Load Vout = 9.8V
Loaded Vout = 9.5V and reading drops
by ~10mV every 2sec
After the first test the battery reading changed again:
No Load Vout = 9.55V
Loaded Vout = 9.29 and reading drops
by ~10mV every 2sec

Is this a normal behavior for battery of this type ?

 

[Luhan]

I bought a 9V Lithium cell primary battery (single use battery, not Li-Ion
rechargable like in cellphones).
I suspect it might be old or not in good condition. To test it I hooked it
to 500 Ohm resistor and measured
the output voltage:
No Load Vout = 9.8V
Loaded Vout = 9.5V and reading drops
by ~10mV every 2sec
After the first test the battery reading changed again:
No Load Vout = 9.55V
Loaded Vout = 9.29 and reading drops
by ~10mV every 2sec

Is this a normal behavior for battery of this type ?

Looks like a 'surface charge' to me. Nomimal for Lithium is 3.0 volts
per cell; thats 9.0 volts for your battery. Try 100 ohms/1watt
resistor for a minute or so. You should still see about 9 volts after
that. Does the battery have a stated mah rating?

Luhan Monat (luhanxmonat-at-yahoo^dot^com)
http://members.cox.net/berniekm/
"Reality: what a concept!"

 

[Phil Allison]

"Vadim Bishtein"

I bought a 9V Lithium cell primary battery (single use battery, not Li-Ion
rechargable like in cellphones).
I suspect it might be old or not in good condition. To test it I hooked it
to 500 Ohm resistor and measured
the output voltage:
No Load Vout = 9.8V
Loaded Vout = 9.5V and reading
drops
by ~10mV every 2sec
After the first test the battery reading changed again:
No Load Vout = 9.55V
Loaded Vout = 9.29 and reading
drops
by ~10mV every 2sec

Is this a normal behavior for battery of this type ?

** Yes - 9 volt batteries ( all types except the rechargeables) drop
about 0.5 to 1 volt rapidly in the initial minutes - then settle down and
have a long period of fairly steady discharge.

See the graphs here:

http://www.thomas-distributing.com/9v-ultralife-batteries-9-volt.htm




....... Phil