Differences

This shows you the differences between two versions of the page.

Link to this comparison view

--- en:ev:bms [2020/04/22 18:04] – ruudi s
+++ en:ev:bms [2020/07/20 09:00] (current) – external edit 127.0.0.1
@@ Line 8: / Line 8: @@
 Its ok to use it on a usual ICE car starter battery because they mainly are 12Volt batteries.
-On electric cars its not very often so, only BMW is using this at the moment (2020) on their only EV BMW i3.
+On electric cars its not very often so, only BMW is using this unit at the moment (2020) on their only EV, BMW i3.
-Now they offer 120Ah battery for the car but when they started to sell this model (in 2013) it had half the capacity 60Ah.
+Now they offer 120Ah battery for the car but when they started to sell this model (in 2013) it had half the capacity 60Ah in the same space.
-In a few years batteries have gone twice as better! 60Ah is 22kWh and 120Ah battery is 42kWh.
+In a few years batteries have gone twice as good! i3-s 60Ah is 22kWh and 120Ah battery is 42kWh.
-To describe batteries on EV-s is mainly in use unit kWh kilo Watt hour. This is unit for measuring electric energy and it fits
+To describe batteries on EV-s mainly is used unit kWh kilo Watt hour. This is unit for measuring electric energy and it fits much better with cars since they use a lot of energy. Kilo Watt hours is also used to measure home energy consumption. Only difference is that you multiply Volts with Ah and you get Watt hours if there are many of them then you will use prefix kilo.
-much better with cars since they use a lot of energy. Kilo Watt hours is also used to measure home energy consumption. Only difference is that you multiply Volts with Ah and you get Watt hours if there are many of them then you will use prefix kilo.
 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.
+{{:en:ev:leafi_aku.jpg?300|}}
+Nissan Leaf battery without box
 ===== Safety =====
@@ Line 21: / Line 24: @@
 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.
-Main problem with battery safety is that you cannot
+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:
+  - + contactor
+  - - contactor
+  - manual safety disconnect connector
+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

en/ev/bms.1587578657.txt.gz · Last modified: 2020/07/20 09:00 (external edit)