Carl warned me a couple weeks ago I should order some new batteries to have on hand when he needed them. Tonight the need finally arrived - I came home to find Carl getting off and back onto his dock almost immediately.
A little surgery and he is now happily running the new set of 8 Eneloop 1900 mAh NiMH AA cells at a cost of US$24.
The prior battery set lasted 8648 hours ( 1yr ) of 24/7 operation through 821 charge/discharge cycles averaging 10.5 hours each cycle. (At US$0.146 per KWH, Carl cost about $5.75 per year in electricity.)
Carl might be “old school” still powered by NiMH AA cells, but his power management software design and charger are tailored to this battery configuration and I do not want to re-open that can of squirming worms. I am curious how many cycles Carl would get from the more powerful official GoPiGo3 Li-Ion pack, but decided “if it works, don’t fix it” - (at least this time).