Motor on a reasonable budget

[BrianG]

zip charging is simply charging through a long wire directly from the power source to the battery. It relies on the fact that there is resistance in the wire to limit the current somewhat. To me, it's just too unreliable as the charge current would depend on the voltage of the power source, the voltage of the battery, and the gauge/length of the wire. In any case, the supply voltage has to be higher than the battery voltage. So, for 6s A123s, you'd need at least 22-23v. But if it's too high, the charge current will skyrocket as well. Best to just use a charger IMO.

Oh, and I would not do this on ANY lithium battery except A123s as they are much more tolerant.