Paul,
Many thanks for the advice on this. Can do.
Bob
To avoid tossing a good battery you can do a test similar to
that used on our Concorde batteries. Take the amp-hour rating (C1)
and draw a load and measure the amps and time down to the threshold of 10v or
20v depending on the battery. If we can get 80% of the rated A-H
capacity we keep it. But, we use a normal discharge rate in the airplane,
not a full draw at C1 as I think that is unnecessary. So, maybe something
like 20% of C1 discharging through some lights for example or a rate that
duplicates a discharge rate in the airplane in your worst condition so that it
will show up any faults under load. Take a measurement every X minutes
and get your capacity. I'd do it on the bench out of the airplane and
track the capacity between annuals.
We previously tossed these expensive batteries based on
calendar life but we can now leave them on condition using these tests.
On 2010-06-19, at 3:01 PM, Robert R Pastusek wrote:
Just
had two of my four Odyssey PC680 batteries crap out after 2 years of service
although an identical set on the other buss are fine…
Robert,
I have a similar setup in my IV-P and had planned to replace two of the four
batteries every two years, expecting them to last for four years…but I never
looked at the expected/advertised life; I was just following a practice used
for lead/acid batteries. Two of my batteries are coming up on two years old;
the other pair are coming up on four years, and I’d planned to replace them
during the condition inspection next month. I’d appreciate your
thoughts/experience on this.