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| en:ev:bms [2020/04/22 18:15] – ruudi s | en:ev:bms [2020/07/20 09:00] (current) – external edit 127.0.0.1 | ||
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| For example New 2020 Nissan Leaf you can buy with 40kWh or 62kWh battery. The biggest batteries on road cars are right now 100kWh Tesla Model X. But allready manufacturers claim that there will be EV pickup trucks with 200kWh batteries and so on. | For example New 2020 Nissan Leaf you can buy with 40kWh or 62kWh battery. The biggest batteries on road cars are right now 100kWh Tesla Model X. But allready manufacturers claim that there will be EV pickup trucks with 200kWh batteries and so on. | ||
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| + | Nissan Leaf battery without box | ||
| ===== Safety ===== | ===== Safety ===== | ||
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| Theres also high voltage risks, for example big crash and high voltage orange wires will be revealed. In that case EV control system will switch high voltage system off. Also there is new danger in the car workshop where technicians need to be trained to service and fix these cars. | Theres also high voltage risks, for example big crash and high voltage orange wires will be revealed. In that case EV control system will switch high voltage system off. Also there is new danger in the car workshop where technicians need to be trained to service and fix these cars. | ||
| Crash tests are performed to design and make safe case for the battery. Same as with petrol cars where is flammable liquid in the petrol tank. | Crash tests are performed to design and make safe case for the battery. Same as with petrol cars where is flammable liquid in the petrol tank. | ||
| - | Main problem with battery safety is that you cannot momentarily switch off the battery cell. In case of situation that there is a problem outside of battery box then there is no problem EV battery has 3 means of switching possibilities: | + | Main problem with battery safety is that you cannot momentarily switch off the battery cell. In case of situation that there is a problem outside of battery box then there is no problem EV battery has 3 means of switching possibilities: |
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| + | picture of contactor and safety disconnect on a car Leaf | ||
| + | But when it comes to enter into the battery box then there is quite a big danger ofcourse untrained persons are not allowed to make any repairs on EV-s but it will happen sooner or later. Main problem is that batteries will always have their charge even when they are discharged they have minimum of 3V per cell this makes 96*3V=288V of DC! | ||
| Batteries need to be taken care of not to overcharge and undercharge. Nowadays 400V EV batteries consist of 96 cells connected serially. Each serial cell voltages are monitored that is the job of BMS | Batteries need to be taken care of not to overcharge and undercharge. Nowadays 400V EV batteries consist of 96 cells connected serially. Each serial cell voltages are monitored that is the job of BMS | ||
