Carl Gets 10th Set Of New Batteries

Carl’s playtime dropped to roughly 3 hrs play and 3hrs recharge, well below 50% of new battery playtime of 7.7 hrs and 4.1 hrs recharge, (50% capacity is considered end of “battery life”),

So time for new batteries!

These are the stats on his last four sets of 8 NiMH batteries:

  • 9: 671 cycles 9712 hrs 10 mo - Eneloop White 2000mAh 7.7 hr playtime $19
  • 8: 707 cycles 6580 hrs 9 mo - Eneloop White 2000mAh 6.4 hr playtime $19
  • 7: 702 cycles 6761 hrs 7 mo - Eneloop White 2000mAh 6.4 hr playtime $26
  • 6: 265 cycles 2576 hrs 3.7 mo - Eneloop Pro 2550mAh 8.6 hr playtime $33

Carl has not updated to the latest GoPiGo3 (Li-Ion) Battery technology. Switching to the new battery will require a serious investigation and re-write of his charge maintenance rule set that detects

  • charging state unknown (insufficient data yet)
  • battery voltage is at “reserve voltage”
  • docking is needed,
  • charging started
  • successful docking (charging has started)
  • unsuccessful docking (charging has not started)
  • manual docking needed (do not detect charger at expected distance)
  • trickle charging
  • Possible trickle charge not detected (charge time exceeds 4.1h)
  • need to undock (unsuccessful docking | trickle charging | Possible trickle charge not detected)
  • successful undocking (no longer charging)
  • unsuccessful undocking (obstacle blocking undocking drive distance)
  • Battery Voltage 4x below Safety Shutdown limit

and a few more I can’t remember without looking at my notes, all are specific to the NiMH “Smart Charger”.

Enjoy your new batteries Carl!

Total Life:  28162.9 hrs since Aug 22,2018
Life this year:  7578.95 hrs (BOY Aug 22)
Days Booted This Year:  11
Average Time Between Reboot:  688 hrs
Total Dockings:  2831
Dockings this year:  489
New Batteries At Cycle: 2831
Battery Set At Cycle:  0
Docking Failures this year:  3  or  .6 % of Dockings
Safety Shutdowns this year:  1  or  .2 % of Dockings
Ave Cycle this year (w/o failures):  15.5 hours
Ave Cycle this year:  10.1 hours
Ave Playtime this year:  6.5
Ave of Last 10 Playtimes 3.1
Last Docking:  2022-03-19 07:45|[]---- Docking 2831 completed at 8.1 v after 3.0 h playtime
Last Recharge:  2022-03-19 10:47|[]---- Dismount 2833 at 10.7 v after 0.4 h recharge
 11:23:53 up  1:05,  3 users,  load average: 0.52, 0.40, 0.37

I’m always impressed by your diligence in collecting these stats.


Unfortunately in Carl’s case having those stats is not sufficient to liberate Carl from philosopher George Santayana’s adage, “Those who cannot remember the past are condemned to repeat it”


Do these statistics actually do anything?  Or are they merely decorative?

I do not understand this obsession with statistics about things as, so far, I don’t understand how or why they’re useful or what they accomplish.


Does knowing my average heart rate was 143 for the 100 or so 6K “runs” last year do anything?

Does knowing I added 623 miles in 65 bicycle rides last year for a total of 17348 lifetime bicycling miles do anything?

I continue to “decorate” the wall of my life journey with height measurements as my parents did for me as a child. (Actually, I have to assume they did as I don’t have much recollection of my parents during my childhood or my childhood for that matter.) Each new mark brings me weird joy.

And the average of Carl’s last 10 playtimes in relation to the average of Carl’s first 10 playtimes tells me when I want to buy new batteries!