The issue of whether or not Zero does some leveling and meter calibration at the factory aside - here is some information I've gleamed from the
battery university about Li Ion batteries in general...
Li Ion differs from NiMH, in terms of break in and care, in that there is no chemical memory to overcome and prevent, but they still have other electronic needs for charging care. Because the Li Ion failure modes for overcharging or overdepletion can be permanent or sometimes dangerous, they all have circuitry that monitors the state of charge to prevent those conditions. That circuitry is conservative by design because flirting with the "over" states is not wise. As a result the circuits may be limiting the use of the battery until they can take some measurements.
It is the circuit's job to prevent over-charging. It is also the circuit's job to prevent over-depletion, but only during normal operation. If you discharge until it shuts the device off, then you should recharge soon, and while typically "soon" is measured in terms of weeks, not seconds, "as soon as you can" is the best recommendation.
The good news is that the only thing that can really go wrong (other than depleting it beyond recoverability which would require draining to zero and then leaving it uncharged for quite some time) is that the battery meter can become inaccurate. With a multi-cell pack, though, the cells can also become unbalanced in that their state of charge isn't even and so they need to be leveled again. All of that is recoverable unlike the chemical "memory effect" of NiMH, and it will recover itself slowly over time if you use the battery sufficiently.
Leveling can apparently happen by just leaving the battery on the charger for long periods of time, but the process outlined above could potentially make it happen a little faster. Think of trying to get charge into the cells that are less full when you have to be careful of overcharging the cells that are already full as compared to having all of the cells in a 25%-ish state and potentially they will equalize as they actively charge from 25% to full. This is most likely aided by the fact that the recharging is not linear so while the "more full" cells approach full and take in power more slowly, the "less full" cells are still in their aggressive phase and close the gap. If you rely on the topping charges to accomplish the same effect (Li Ion is not trickle charged, instead the charger cuts off and waits for the cells to drain a bit then "tops them back up") you would have to go through a lot of topping cycles to get there.
(And, again, depending on how sophisticated the charging circuitry is, there could be a way to conditionally cut off only the full cells and keep charging the others, but that is hard to do when the various cells in one of the "packs" are hardwired together for high voltage/current delivery...)
The battery meter issue is most quickly cured by a full cycle of draining til the device shuts itself off and then charging to full and leaving it on the charger for a couple of hours more as the full indicator on different devices may refer to various states of charge near, but not at, full. This lets the battery meter circuit visit both ends of the battery's current natural capacity and be able to take accurate readings that let it better predict how much charge is left. Just using and recharging the battery will tend to give it a reasonably frequent taste of what "full" feels like, but an occasional (emphasize occasional) full discharge will give it a taste of the other end of the cycle. The battery university
recommends mostly partial charge cycles with a recalibration cycle maybe once every 40 or so charges. I didn't see an article on there that specifically addresses the multi-cell packs found in electric vehicles, though.
I'm guessing the 25% in the recommendations encourage faster leveling and until leveling happens a discharge to 0 probably runs the risk of overdepleting one or 2 cells while their brothers are still able to provide power. The protection circuit may also discover that some cells are getting overdepleted when it thought it had 10% power left and may need to more suddenly enter "creep" mode than it would if all cells were really at 10%.
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Topic: Zero S-9 Battery breakin (Read 2028 times)