MS800 diagnoses lithium-ion battery electric vehicles now
While the heart of a car used to be its engine, it is now the high-voltage battery. It's the battery that provides the maximum usable range. All electric cars are built around the battery. The first electric cars used nickel-metalhydride (Ni-MH) batteries, and a few years later lithium-ion cells became the standard for electric cars.
What is the life expectancy of an electric cars lithium-ion battery?
Modern high-voltage lithium-ion battery has a complex design and high durability due to:
- charge/discharge controller;
- thermal regulation system;
- an additional reserve capacity to compensate for capacity loss over time.
Electric car manufacturers typically guarantee the battery for eight years and assure that the capacity does not drop below 70 per cent of its original capacity during that time. Tesla claims their car batteries lose capacity at a rate of 2.3% per year, so after eight years the battery will have more than 80% of its original capacity.
The biggest impact on the longevity of a high-voltage battery is the presence of a thermal management system, as overheating of the battery cells leads to rapid degradation of the battery modules. The batteries of early electric cars and hybrids do not have a thermoregulation system. The batteries of low-cost electric cars also do not have it. For example, the air-cooled battery of the KIA Soul electric car suffers from rapid degradation of the upper cells. Batteries without thermoregulation system fail much faster.
What to do if you have a battery problem?
If your battery capacity drops significantly, there is no need to rush out and replace it with a new one. Buying a new battery is quite costly. For a small amount of money, you can check the battery modules and see if it can be repaired. At the same time, battery diagnostics allows you to determine the capacity of the battery after reconditioning. Based on the results, you can make an informed decision whether to recondition the battery or buy a new one.
Diagnosing an electric vehicle's high-voltage battery
The MS800 tester has been developed specifically for diagnosing electric vehicle high voltage batteries and hydrides. MSGequipmenthas prepared a software update for the tester which, in addition to nickel-metal hydride modules, allows the MS800 tester to also test lithium-ion cells. Maximum charge and discharge currents of all types of modules: 4.5A per charge and 6A per discharge. Up to 36 cells can be tested simultaneously. Module temperature control during the charge/discharge process prevents damage to the tested modules during diagnostics.
Besides battery diagnostics, the MS800 allows you to match similar capacity boo cells. Lithium cells can only be inserted into the battery if all cells have the same voltage. Any unbalance of cells will reduce the capacity of the assembled battery and increase the self-discharge rate. Too large a difference in voltage between cells of 200 mV or more (the value is different for different electric vehicle models) can lead to an unbalancing error in the BMS module. With the MS800 tester it is possible to balance the cells by charging or discharging them to a certain voltage with high accuracy.
For service stations the tester MS800 has one more useful function – keeping in working condition the cells, which are stored in the warehouse. There is such a property as self-discharge in any batteries. Batteries that have been stored for a long time should be periodically checked for charge level and recharged if necessary. For lithium batteries, the optimum capacity for long term storage is between 30% and 60%. Do not store fully discharged batteries as this will result in a loss of capacity.
