Elektrikli Bisikletin Pili Ne Zaman Şarj Edilmeli? BMS'nin görevi.

In this video, I'll try to explain some frequently asked questions about charging, such as whether the battery should be charged when it's depleted or partially charged, without delving into too much detail. First, let's take a look inside an electric bike battery. We'll see that it contains 40-50 18650 Li-ion cells and a BMS (Battery Management System) circuit. The batteries used in our cell phones, power banks, and laptops share the same technology as these Li-ion batteries, except that they're rectangular, rather than cylindrical, to fit the phone. These batteries are preferred for electric bikes because they're relatively lightweight compared to their high capacity. While they can be recharged 2000 times, manufacturers claim that standard batteries can be fully charged 300-500 times. Another little-known feature of 18650 batteries is their high instantaneous current output. A 10C battery with a capacity of 2200 milliamperes can deliver up to 22 amps. You can imagine this unsustainable power as a runner sprinting. We feel it when climbing steep hills or making sudden starts on an electric bike. Riders are often surprised by the fact that such tiny batteries can easily carry a load of 120-130 kilograms. This is the underlying technology. High-quality batteries have a high discharge current and a high discharge coefficient, a key factor in cost. This is also the reason for the "stall" and "no traction" phenomenon in bikes with low-quality batteries. These batteries have two negative characteristics: first, they are highly prone to burning and exploding. Even a few batteries pose a serious risk, while in bicycles, batteries stacked in groups of 40-50 are quite dangerous. They must be protected from impacts, heat, and water, and the person handling them must be knowledgeable in this field. Especially those of you who say, "I'll buy the batteries and make my own," please reconsider. Another negative aspect of these batteries is their extreme sensitivity to usage, that is, their charge-discharge ratio. If you completely discharge them or continue charging them past their capacity, the battery will fail, meaning it won't hold a charge. Yes, the battery will be trashed; it's that sensitive. This is where the BMS (Battery Management System) comes into play. This circuit takes care of each battery individually, like a child. Of course, batteries produced by the same manufacturer, from the same batch, are expected to be very similar and behave similarly. This is true on the first day, but after a year or two, batteries start to differ due to various factors. These very small differences gradually increase. By the third or fourth year, it's no surprise to see some of the 40 cells in our battery pack completely deteriorated and no longer holding a charge. Remember, the theoretical lifespan of 18650 batteries is 3 years. The BMS circuit charges each battery gently, with a suitable current of up to 4.2 volts, without allowing them to overheat. Li-ion batteries shouldn't be allowed to drop below 2.8V; if they do, they will be damaged irreversibly. This prevents the battery from completely draining, as in the previous examples, by always maintaining a certain voltage level. So, after this technical information, let's clearly answer the question "When should we charge?" You can charge it whenever you want, so treat it like your cell phone. After all, the BMS circuit protects your battery for you. For those who aren't confident, I can suggest the following: We've discussed the workings of BMS circuits, and it wouldn't hurt to leave your battery plugged in for a day or two, just like this circuit. You can extend the battery's lifespan by 3-5%, but I don't think it's worth the effort. However, these two are crucial when it comes to electric bikes; pay attention to them. First, as I mentioned earlier, some of the 40-50 batteries can fail, or your BMS circuit could malfunction. If you notice any abnormalities during use, never use the battery; take it to a qualified technician. For example, if it's overheating, takes longer than 4-5 hours to charge, is swollen, or emits a smell, there's a problem. A problem you could fix for 40-50 lira could quickly lead to battery failure. The second option is to leave the bike at the "standby voltage" specified by the battery manufacturer during the 2-3 months of winter when you're not using it, which is generally around 60%. You can find this level in your bike's manual or service center. Of course, if you can, charging it every two weeks and then riding the bike until the battery is half-charged is a better idea. However, leaving the battery sitting for 2-3 months while it's flat or fully charged will shorten its lifespan. As a bonus tip, electrical devices are known to be sensitive to heat. Try not to leave your bike in the sun, especially the battery. Furthermore, when riding uphill for extended periods, the motor and battery will overheat, which can significantly damage the e...