Plug and play
Maverick Diagnostics has teamed up with Austrian tech specialists AVILOO in order to make EV battery testing easier for garages and motorists
Published: 07 July, 2023
Cheltenham-based electric vehicle specialists Cleevely EV were the hosts for the recent unveiling of a new battery testing device being brought to the market by Maverick Diagnostics.
Austria-based battery diagnostic specialists AVILOO have joined forces with Maverick to bring their new Flash test to the UK, through which users can assess the condition of the battery on an EV in three minutes. The tool assesses vehicle communication, battery controller, HV battery state, LV system and battery history, which enables it to produce a score between one and 100, rating the condition of the battery. The user can then provide the score and overall findings to customers via a report.
The company has developed the Flash test, building on the foundation offered by the more in-depth Premium test. This requires the car to be driven so that the battery can drain from 100% to 10%. A full state of health (SoH) result can be garnered from this. The sheer mass of data that AVILOO accrued testing thousands of EVs has enabled the company to get to the point where it can offer the faster snapshot provided by the Flash test. While the result is more comprehensive, the Premium test does takes several hours to perform, and for garages and other users that might need a more rapid picture of the condition of a battery, a speedier offering was required.
The Flash test comes in two parts; The Aviloo box hardware that collects the data, and the AVILOO platform, which receives it and provides the result. There is also the AVILOO app. These are the key components enabling users to perform the Flash test.
AVILOO Chief Technical Officer Nikolaus Mayerhoffer demonstrated live how the test is performed. To use the Flash test, the user connects the AVILOO box to the vehicle via the OBD port. Then, a flashing yellow LED light says the test is starting. The user then starts the vehicle. The LED turns green when the test is complete. The report is then created and sent to the e-mail address synced to the device.
Solution
At present, AVILOO can test around 80% of current EV and plug-in hybrid models. Explaining the company’s background, AVILOO MD Dr Marcus Berger commented: “We are based in Austria. The company was founded by my brother and our Chief Technical Officer Nikolaus Mayerhoffer. The aim was to do battery software. We have 30 employees and we believe we are market leaders on battery analytics especially with EVs. Our office is in a KIA showroom. We can drive cars in. It us a typical start-up. The AVILOO flash test is a quick test. in three minutes, you get an assessment. The Premium test has led to the flash test.”
According to Marcus, the issue that the Flash test offers a solution to is very easy to grasp: “The key problem is battery life. It is familiar to anyone who has a phone. We started with the Flash test in late 2021. We are now in the UK with Maverick Diagnostics. All of our activities are being managed through Maverick.”
Solution
According to AVILOO’s Nikolaus Mayerhofer, regular battery testing is very important: “Traction batteries are chemical energy storage devices that are subject to a natural ageing process due to load and lose their storage capacity over time. Likewise, usage behaviour, such as permanent driving in the upper power range or frequent charging with high charging powers, can lead to faster battery ageing.”
He continued: The AVILOO Premium test was the origination of our company. This was the original idea; If you buy a used EV, you need to know the battery’s state of health. If it is not good or you can’t get the range you have not spent the money properly. If you want to swap the battery, it could cost several thousand pounds.
“We took this product to the market, but dealers said ‘we cannot drive the car down to 10% to test it. We need something faster’. So, we developed the Flash test. You just need to plug it in for three minutes” Because it is a rapid test, a different way of gauging the information was needed: “Far less data is being collected, which is obvious, so you can’t do a full state of health, which is why we developed the AVILOO score, which gives you a decent idea of the battery.”
On how this is made possible, Nikolaus said: “Because we have all the data from the Premium test, we can take this data and use it, interlinked with the flash test. This is why it is so difficult for the competition to deliver something similar. We have collected data for thousands of different cars.” On what makes it so useful, he noted: “SoH varies at 100,000 kilometres from 98% to 68%. This is why we believe there is a huge need for a battery test. Many people do not understand this. They think, as with combustion engine vehicles, you can assess a car on age and mileage. With EVs you need to consider how it was charged.”
On how the different offerings are being taken up, Nikolaus said: “The Premium test is very much a consumer product. Although we have been offering it to car dealers, typically consumers are the ones buying it.” On the wider offering, taking in the Cloud platform, Nikolaus said: “Our cloud platform can be offered to workshops to find the root cause of the battery problem.” This shows where a car is being driven, and how the battery is charging or discharging, and also shows the voltage spread from the highest to the lowest.”
This has led to some surprising real-world results, as Nikolaus explained: “One customer came to us, with a range issue – the car had half the range it should have. He had taken his Nissan Leaf to two dealers but they could not help him. His Leaf displayed a transference state of health, but it was not the truth. We proved Nissan was completely off. Also, when he was accelerating without eco mode for 30 seconds the car would stop suddenly. To prove this is super-complicated because it takes hours to test. In this case he put the Flash test box inside the car. We then told the customer to provoke the problem. Eventually climbing a hill, we had the result. The cell voltage had dropped to 1.4V. We proved there was major damage in the battery. We could replicate the event, and we proved there was no fault code for this either. We also showed there was a safety risk and risk of fire. After six months, the driver got a replacement battery from Nissan.”
Accurate and reliable
The system is already available in Austria, Germany and across Scandinavia, and now the UK. On the team-up with AVILOO, Andy Brooke, Managing Director at Maverick Diagnostics, added: “Our partnership with AVILOO represents a game-changing opportunity for workshop owners and technicians. This is the first test of its kind. Customers can now see, in the simplest form, what condition their EV or plug-in hybrid’s battery is in. The technician can then use this accurate and reliable information to make a reliable assessment and, potentially, justify a battery replacement.”
Users lease the AVILOO box for the Flash test, and pricing is on a subscription model, with a range of prices based in usage. The Premium Test is available for £99.
For more information, visit: www.batterydiagnostics.co.uk
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- EV sales second only to petrol in 2022
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- technologies of electric and hybrid vehicles
In the previous two issues, we looked at the way batteries store energy. We could in fact compare a battery to a conventional fuel tank because the battery and the tank both store energy; but one big difference between a fuel tank and a battery is the process of storing the energy. Petrol and diesel fuel are pumped into the tank in liquid/chemical form and then stored in the same form. Meanwhile, a battery is charged using electrical energy that then has to be converted (within the battery) into a chemical form so that the energy can be stored.
One of the big problems for many potential owners of pure electric vehicles is the relatively slow process of
re-charging the batteries compared to the short time that it takes to re-fill a petrol or diesel fuel tank. If the battery is getting low on energy, the driver then has to find somewhere to re-charge the batteries, and this leads to what is now being termed ‘range anxiety’ for drivers.
Whilst some vehicle owners might only travel short distances and then have the facility to re-charge batteries at home, not all drivers have convenient driveways and charging facilities. Therefore, batteries will have to be re-charged at remote charging points such as at fuel stations or motorway services; and this is especially true on longer journeys. The obvious solution is a hybrid vehicle where a petrol or diesel engine drives a generator to charge the batteries and power the electric motor, and for most hybrids the engine can also directly propel the vehicle. However, much of the driving will then still rely on using the internal combustion engine that uses fossil fuels and produces unwanted emissions. The pure electric vehicle therefore remains one long term solution for significantly reducing the use of fossil fuels and unwanted emission, but this then requires achieving more acceptable battery re-charging times.
Charging process and fast charging
Compared with just a few years ago, charging times have reduced considerably, but there are still some situations where fully re-charging a completely discharged electric vehicle battery pack can in take as long as 20 hours. It is still not uncommon for re-charging using home based chargers or some remote chargers to take up to 10 hours or more.
Although there are a few problems that slow down charging times, one critical problem is the heat that is created during charging, which is a problem more associated with the lithium type batteries used in nearly all modern pure electric vehicles (as well as in laptops, mobile phones and some modern aircraft). If too much electricity (too much current) is fed into the batteries too quickly during charging, it can cause the battery cells to overheat and even start fires. Although cooling systems (often liquid cooling systems) are used to help prevent overheating, it is essential to carefully control the charging current (or charging rate) using sophisticated charging control systems that form part of the vehicle’s ‘power electronics systems.’
Importantly, the overheating problem does in fact become more critical as battery gets closer to being fully charged, so it is in fact possible to provide a relatively high current-fast charge in the earlier stages of charging; but this fast charging must then be slowed down quite considerably when the battery charge reaches around 70% or 80% of full charge. You will therefore see charging times quoted by vehicle manufacturers that typically indicate the time to charge to 80% rather than the time to fully charge. In fact, with careful charging control, many modern battery packs can achieve an 80% charge within 30 minutes or less; but to charge the remaining 20% can then take another 30 minutes or even longer.
Battery modules
Many EV battery packs are constructed using a number of individual batteries that are referred to as battery modules because they actually contain their own individual electronic control systems. Each battery module can then typically contain in the region of four to 12 individual cells. One example is the first generation Nissan Leaf battery pack that contained 48 battery modules that each contained four cells, thus totalling 192 cells; although at the other extreme, the Tesla Model S used a different arrangement where more the 7,000 individual small cells (roughly the size of AA batteries) where used to form a complete battery pack.
The charging control systems can use what is effectively a master controller to provide overall charging control. In many cases the electronics contained in each battery module then provides additional localised control. The localised control systems can make use of temperature sensors that monitor the temperature of the cells contained in each battery module. This then allows the localised controller to restrict the charging rate to the individual cells to prevent overheating. Additionally, the localised controller can also regulate the charging so that the voltages of all the cells in a battery module are the same or balanced.
One other problem that affect battery charging times is the fact that a battery supplies and has to be charged with direct current (DC) whereas most charging stations (such as home based chargers and many of the remote charging stations) provide an alternating current (AC). Therefore the vehicle’s power electronics system contains a AC to DC converter that handles all of the charging current. However, passing high currents through the AC to DC converter also creates a lot of heat, and therefore liquid cooling systems are again used to reduce temperatures of the power electronics. Even with efficient cooling systems, rapid charging using very high charging currents would require more costly AC to DC converters; therefore, the on-board AC to DC converter can in fact be the limiting factor in how quickly a battery pack can be re-charged. Some models of electric vehicle are actually offered with options of charging control systems: a standard charging control system which provides relatively slow charging or an alternative higher cost system that can handle higher currents and provide more rapid charging.
Home & Away
One factor to consider with home based chargers is that a low cost charger could connect directly to the household 13-amp circuit, which would provide relatively slow charging of maybe 10 hours for a battery pack. However, higher power chargers are also available that connect to the 30-amp household circuits (in the same way as some cookers and some other appliances); and assuming that the vehicle’s AC to DC converter will allow higher currents, then the charging time could be reduced to maybe 4 hours operate (but note that all the quoted times will vary with different chargers and different vehicles).
Finally, there are high powered chargers (often referred to as super-chargers) that are usually located at motorway services or other locations. These super-chargers all provide much higher charging currents to provide fast-charging (as long as the vehicle electronics and battery pack accept the high currents); but in a lot of cases, these super-chargers contain their own AC to DC converter, which allows direct current to be supplied to the vehicle charging port. In effect, the vehicle’s on-board AC to DC charger is by-passed during charging thus eliminating the overheating problem and the high current DC is then fed directly to the battery via the charging control system.
In reality, the potential for re-charging a battery pack to 80% of its full charge in 30 minutes or less usually relies on using one of the super-chargers, but battery technology and charging systems are improving constantly, so we
will without doubt see improving charges times for
newer vehicles.
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