Thanks for the great suggestions! Brushing those connectors once a month is probably good maintenance. FWIW I believe I've read it's not a good idea to leave the battery hooked up to the charger all the time, that they need to cycle to stay healthy.
Have fun out there!
Very late answer: from
https://www.apple.com/batteries/why-lithium-ion/
"Apple lithium-ion batteries work in charge cycles. You complete one charge cycle when you’ve used (discharged) an amount that equals 100% of your battery’s capacity — but not necessarily all from one charge. For instance, you might use 75% of your battery’s capacity one day, then recharge it fully overnight. If you use 25% the next day, you will have discharged a total of 100%, and the two days will add up to one charge cycle. It could take several days to complete a cycle. The capacity of any type of battery will diminish after a certain amount of recharging. With lithium-ion batteries, the capacity diminishes slightly with each complete charge cycle. Apple lithium-ion batteries are designed to hold at least 80% of their original capacity for a high number of charge cycles, which varies depending on the product."
My rmbp 13" late 2013 is the best laptop I've had, the battery (still original) lifetime is light-years better than my TiBook and Santa Rosa were. I have been keeping it on the charger most of the time and use it too much per day. Right now it tells me:
Charge Information:
Charge Remaining (mAh): 4194
Fully Charged: Yes
Charging: No
Full Charge Capacity (mAh): 4413
Health Information:
Cycle Count: 445
Condition: Service Battery
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 12509
I went through a phase of taking the battery for a walk once a day but have gone back to avoiding discharges, on the understanding that the overall lifetime depends on total number of completed charge cycles. It'll still give me maybe four hours battery life from 100%-20%, but 20 sets off my irrational internal alarm system and I stick it on charge again.
