happy new year, folks.
so i'm 8 weeks out of surgery and the shoulder is getting better, and well enough to ride.
if you recall, i moved offices and no longer can charge where i park the bike. and the 4s subpack (2x 5800mah for 11.6Ah) was starting to die, leaving me with nowhere near the capacity i'd need to commute to work and back, esp at high amps w/ the maxe.
so i decided to make a new detachable pack that i could bring to my desk and charge w/ the bulk charger. and i could balance charge at home w/ the coil. seems reasonable, right? i'm not terribly psyched about having to unscrew the BMS connector from the controller each time, but if it goes well, i could cut the BMS cable near the pack and use andersons, since it's only 4 wires.
rather than buy 2 new 4s zippy 5800 packs, i decided to use the 6s packs that have been in storage in the garage for a couple years (waiting on the thudbike). cause since i was changing the config, why not jump up from 20s to 22s?
so i first made the balance wire harness for 3x6s and 1x4s:
i attached the maxe to the downtube and started planning the battery pack layout:
two 6s packs are about 4" wide so the steel frame wasn't going to work, and i decided to finally try out molding the kydex around a form i tacked together:
and made 3.5" + 3/4" for 4.25":
then the layout and forming:
i formed some of the excess around the top and seat tubes to see how well it 'snapped on':
then i started to attach my balance harness but wasn't paying attention and put it backwards, and shorted a wire, which i replaced easy enough:
to get the pack in and out easily, i cut off the top (and plan on adding a second piece top). i reconfigured the BMS for 22s and started charging/balancing:
even after balance charging all the cells to 3.86 before attaching/paralleling them, i found they were way out of balance.
i'd also upped my bulk charger voltage to 92V btw, but saw the top cells rise over 4.2V so unplugged it and let them balance for hours and hours but not long enough to balance them.
today was my first day back so i taped the loose bits together and rode it in, but was very disappointed to get a LowBatt error only halfway in, pulling 80A mind you, but still. so i switched to eco and pedalled the rest of the way to work.
so now i have to decide how to replace the bad cells/packs... when i first checked them, all the 6s packs seemed reasonably balanced for having sat in the garage for 2+ years. all except one which had a cell with reversed polarity.
so maybe they're not worth the effort after all.
if i'm going to buy a replacement or two, i might as well spend a bit more to get new zippy compact 5800mah cells, so at least i'll have the extra capacity to add to the 4x8s packs that i've been using and know are pretty good... especially if i want to enjoy the maxe a bit more.
22s is pretty sweet.