Archive for August 27th, 2012
Five PL605060 lithium cells (prismatic, 3.7 V, 2 A·h) for the longboard project arrived and underwent incoming inspection. The lower curves show the as-received charge state (about halfway) and the upper curves show the first charge:
The crinkly sections come from me nudging the wires (held on by the most tenuous of alligator clip connections) and don’t really affect the results. The five cells charged to within a few percent of each other, which is Good Enough.
I hotwired each cell to the hacked battery case for the SX230HS camera and used the Canon charger:
As is turns out, that charger is rated for 700 mA current, exactly the same as the 4-cell charger we’ll use for the longboard battery, so the overall charge rate should be about the same. The Canon cells run around 1.1 A·h and the PL605060 is 2.0 A·h; I figured 2.0 was approximately 1.1 for small values of 2.0. The charge cycle required only a little more time than usual, which isn’t surprising because I stopped the discharge at 3 V rather than 2.8 or whatever.
Cell C has the highest discharge voltage of the litter, so I’ll conjure it into becoming an external battery for the camera (which prefers higher voltages over higher capacity). I’m not sure how to mount it; a case that screws into the tripod socket is obvious, but it would interfere with the macro lens adapter. Of course, I could just print another macro lens adapter with an integral battery case …