Jon Bloom and the ARRL labs did a great job with the BCR. While we are no longer optimizing the set point for maximum power transfer, the batteries do appear to have been a very good choice and the BCR and solar panels are working in those which are still talkative. The South Atlantic anomaly appears to be the death bringer.
I personally no longer fear batteries as the likely failure mode over the reasonable lifetime of our satellites when designed by someone who knows what they are doing. What these lithiums offer us is much great energy density than we can get with NiCad chemistry. Now it appears the first shots have been fired in making them last a long time. What we don't know yet is how structurally sound these new cells with increased lifetime will be. What will temperature cycling and vacuum do to them, etc.
I hope that this progresses and ends any and all speculation about the wasted effort (my view alone) on capacitors which do not seem to be approaching the energy density of bad batteries. The density curves with caps is looking pretty asymptotic to me. A big leap is needed to make them competitive.
Bob N4HY
On 2/5/2010 7:04 PM, Mark L. Hammond wrote:
Hey, AO-16 and IO-26 still have some decent batteries, even after 20 years or so :)
Check their orbit numbers (80k-100k), and that's very close to the number of time they have been charged/discharged! hehe
Neat on the new technology...but our buddies that built those birds picked some good batteries too!
73,
Mark N8MH