Here are some quick tips for rechargeable battery charging: use original chargers, as they match your battery's specifications; avoid charging in extremely hot or cold conditions; and consider periodic calibration by letting your battery drain fully and then charging it to 100% once a month.
What is a rechargeable battery?
2. Historical development of rechargeable batteries Batteries are by far the most effective and frequently used technology to store electrical energy ranging from small size watch battery (primary battery) to megawatts grid scale enenrgy storage units (secondry or rechargeable battery).
So to answer your question: you can charge it at half, or at a quarter, or fully depleted. I don't think it will matter that much. Just make you fully charge it and not partially charge it. tl:dr - Just keep it fully charged if you want, or at half, it shouldn't hurt the battery pack.
Historically, technological advancements in rechargeable batteries have been accomplished through discoveries followed by development cycles and eventually through commercialisation. These scientific improvements have mainly been combination of unanticipated discoveries and experimental trial and error activities.
So you'd recharge after every use. But also note that lithium cells don't store well at high state of charge - ideally (for a cell life perspective) you'd charge to slightly above half charge, use it to slightly below half charge, then recharge to half charge and store until you need it again.
What happens if you leave a lithium battery at 0% charge?
Incidentally, lithium batteries self-discharge though, so if it says 0% and it's actually at 5%, you can still drain that 5% if you leave it long enough, permanently destroying the battery. They also don't like being at 100% or 0% charge, and they don't like being hot. Both those things will shorten the lifespan of the battery.
Why do EVs need a rechargeable battery?
Batteries for EVs require high energy storage capability in order to deliver power to motor which can drive for prolonged period of times other than for start-up and lighting . Moreover, electric mobility is one of the major industry that uses rechargeable battery as a source of electricity to power up electric motor [, , ].