T
Tim Smith
Guest
I've got six NiMH rechargeable AA batteries, all the same brand and rated
capacity, a one-hour charger, and a flashlight that takes two AA batteries.
I wanted to see how long the light would last on a fully charged pair of
batteries, so I charged up a pair, put them in, and turned it on. I got
5 hours of good light, and another hour of feeble light.
Next pair: *one* hour.
Third pair: 5 hours.
Now for the interesting part. When I put the bad pair in the charger (which
is one of the chargers that does each battery individually), one of them
finishes very quickly (five minutes, tops). This is repeatable (i.e., that
pair has a short life in the flashlight again, and one finishes charging
quickly again).
It seems to me I should be able to deduce something from this, such as that
one of the short lasting pair is defective...but I'm not sure *which* one.
Let's call the one that finishes charging quickly battery X, and the other
battery Y. I don't know enough about how these things work to tell the
following two scenarios apart:
1. Battery X is defective. It somehow makes Y provide all the energy,
and the light stops when Y is discharged. X hasn't provided much
energy, so recharges quickly.
2. Battery Y is defective. It rapidly discharges, then acts as a high
resistence, stopping the light. X recharges rapidly because it hasn't
been asked to provide much energy.
I'll now try each of these batteries with one from one of the good pairs.
Presumably, one of X and Y will play nicely with batteries from the other
pairs, and one will not, and that one that doesn't is the defective battery.
However, I'm curious...should I be able to tell just from what I see at the
charger which of X and Y is the bad battery?
--
--Tim Smith
capacity, a one-hour charger, and a flashlight that takes two AA batteries.
I wanted to see how long the light would last on a fully charged pair of
batteries, so I charged up a pair, put them in, and turned it on. I got
5 hours of good light, and another hour of feeble light.
Next pair: *one* hour.
Third pair: 5 hours.
Now for the interesting part. When I put the bad pair in the charger (which
is one of the chargers that does each battery individually), one of them
finishes very quickly (five minutes, tops). This is repeatable (i.e., that
pair has a short life in the flashlight again, and one finishes charging
quickly again).
It seems to me I should be able to deduce something from this, such as that
one of the short lasting pair is defective...but I'm not sure *which* one.
Let's call the one that finishes charging quickly battery X, and the other
battery Y. I don't know enough about how these things work to tell the
following two scenarios apart:
1. Battery X is defective. It somehow makes Y provide all the energy,
and the light stops when Y is discharged. X hasn't provided much
energy, so recharges quickly.
2. Battery Y is defective. It rapidly discharges, then acts as a high
resistence, stopping the light. X recharges rapidly because it hasn't
been asked to provide much energy.
I'll now try each of these batteries with one from one of the good pairs.
Presumably, one of X and Y will play nicely with batteries from the other
pairs, and one will not, and that one that doesn't is the defective battery.
However, I'm curious...should I be able to tell just from what I see at the
charger which of X and Y is the bad battery?
--
--Tim Smith