As an EE with a fair amount of experience with rechargeable batteries, battery life is mostly dependent on 1) the specific type and design of battery and 2) how the battery is treated.
For example, a fairly new 'flavor' of Li-ion battery is LiFePO4, Lithium-iron-phosphate. It has only half the energy density of other Li-ion formulations, but can easily offer ten times the cycle life, and is far more rugged in high-temperature environments. It's not going to see much use in EVs, however, because of its lower energy density...an 85kWH battery pack would weigh twice as much, and take up twice as much space, as the one in the Tesla. However, even among a specific chemistry (I believe the Zeros use a Lithium Manganese battery, right guys?) there are considerable variations based on anode/cathode configuration, electrolyte, etc. Zero has done a ton of research into all of those specifics, and have specified one that they're comfortable rating at 2500 cycles, and warrantying for five years.
But you can kill just about any battery very fast if you abuse it. There are several things batteries "dislike" (by which I mean you'll shorten their life if you do it): too rapid charging or discharging, over-charging or over-discharging, high temperature operation or storage, sitting for a long time in a discharged state, mechanical distress. All of these battery "dislikes" turn into "hates" depending on degree -- you may get 5000 cycles on your battery pack using the 1/8C onboard charger, which might be reduced to 4000 cycles if you charge by CHAdeMO at 1C, or maybe only 5 cycles if you were foolish enough to rig up a 10C charger. Similarly, I try to recharge before I get below 30% SoC to maximize battery life; if you let the bike get below 10% very often you'll impact battery life at least to some degree; if you go completely down to 0% you'll definitely sacrifice a lot of battery life (ALTHOUGH it may not be possible to take a Zero to a true 0% SoC; the engineers probably built in some safety factor for precisely that reason).
Many batteries can be charged quickly, and safely, but to minimize the impact on battery life, it's best to use a very smart charger with at least a three-stage charging algorithm. If the battery is very discharged, a very low charging current is typically used to revive the battery until its voltage is out of the "nearly dead" range. Then the charging current can be ramped up, until it reaches its maximum, which is often the famous "1C" rate that we often see. This is called the "bulk charging" phase and it's where the great majority of charging of the battery occurs. But as the battery gets near full charge, somewhere near 90% SoC or so, the voltage reaches a value beyond which you don't want to charge, at which the charger usually switches to constant voltage mode, and the current tapers off as the battery tops off. That explains why you'll often see a statement that a battery can be quick-charged to 90% capacity in an hour, two hours to get to 100%. When the charging current drops below a preset value in constant voltage mode, typically the charger will drop down a couple of volts and maintain a "trickle charge" voltage to keep the battery fully-charged as long as it remains on the charger.
The Zero's battery is clearly designed to accommodate quick-charging, since Zero sells a CHAdeMO adapter. As long as you don't try to charge it faster than 1C, if you use a charger that doesn't overcharge it, it never sees very high temperatures, and you don't routinely discharge it to very low levels, you should have no problem getting the rated life out of the battery.
Author
Topic: Battery life and charging (Read 1726 times)