HYBRID VEHICLE BATTERY REGENERATION

What is a battery reconditioning? Should such a procedure even take place? What does the term really mean? How does such HV hybrid battery reconditioning proceed?

Surfing on the Internet, one can come across various articles describing the process of regeneration of any battery. Unfortunately, these materials are usually not written by experts in this field, but rather by people who have little to do with the subject and let their imagination run wild. These descriptions are not supported by knowledge in the field of electromechanics or experience gained in an auto-electrician’s repair shop. They are often written according to the rules of SEO by so-called copywriters, only for gaining clicks and views. They are meant to attract attention and increase the amount of content on the site, rather than to give an honest account of the process, which is still a secret knowledge. Professionals are reluctant to share news from such a hermetic professional environment. In the meantime, we will make an exception, and as an electrician and electronics engineers, we will reveal a corner of the secret to you. We aim to correct and organize the scraps of knowledge that can be found on the Internet.

Self-proclaimed specialists declare that the treatments they can subject batteries to are: cell desulfurization, replacement, cleaning, reconditioning. Next to these items are assurances of the highest level of performance, which can further put your guard down. However, you have to ask yourself: why isn’t the service doing this? Why is there no company on the market that specializes in this? After all, we know many good brands, so Toyota, BMW or Mercedes would have had their own service, component remanufacturing companies for their electric and hybrid models.

The remainder of this post will aim to introduce the concept of regeneration and address concerns about this topic. Let’s start with the fact, that in some cases regeneration can be undertaken and in others a more costly replacement is necessary. As we know, batteries and rechargeable batteries of all kinds are mostly lithium-ion or nickel-metal-hydride and usually last longer than their stated suggested life. So that, they can serve so long and reliably, certain standards of charging, discharging, temperature and battery storage must be maintained. Lack of performance of a common 12 V battery after 3-5 years inevitably leads to its replacement. A similar situation, can be encountered not in an auto repair shop but in a phone service, when it is necessary to purchase and install a new battery in the phone caused by its frequent charging, undercharging to full battery and discharging. Lack of awareness of these factors inevitably leads to battery degradation, which is irreversible at such a stage.

Hybrid vehicle batteries, are nothing different from normal batteries, except that it is a set of cells arranged in sectors, which are watched over by a battery controller. Its task is to receive information about the battery’s charging status and resistance. The received information goes to the converter/inverter. The controller sends data when it should be charged, at what power and how much energy it can give off at any given time. The most common cause of battery failure in an HV system is the weakest cell. Since every battery package, without exception, is just made up of a dozen cells joined together. No cell is the same as its neighboring cells or those at the ends of the battery. During the production of such a battery pack, the battery’s capacity, internal resistance, ability and power to release electricity from itself are all checked with great accuracy. Each cell of a battery pack will put up any resistance during charging or discharging. The excessive instantaneous speed achieved by a hybrid car will rapidly extract the full power from such battery, from all its energy cells, which will further raise their temperature. The longer a hybrid car user wants to feel like a racing driver and treats the car like a Formula 1 car, the faster his battery will degrade. Simply put, at some point the weakest cell will not recharge. It will be the most inappropriate moment, but this is not the rules of mechanics or electrics, but simple human bad luck. I would add, that the rest of the cells will not work then either. Such a cell may also be overcharged and as a result it will be degraded in the eyes of a battery controller. To illustrate the problem, let’s assume that all cells have 8 volts and this one cell has 7 volts, 6.5 v or even 5. This results in an error signaled by the system and failure of the hybrid battery system. The diagnostician sees a system error titled “replace the battery” . The message says we should replace the whole battery, because the system does not provide for regeneration and sees the solution to the problem only in its replacement.

As an independent car repair shop, we do a thorough verification in cases, where the battery is fairly new and little used. Then we boldly propose to our customer to regenerate the battery, by which we mean to replace the cell/cells in question. There are also cases of permanent damage to all cells through improper use for 5-10 years. Then all the cells would have to be replaced. Full regeneration is then rather impossible. It still depends on the model. Several factors contribute to this. Leaving the car with the battery completely discharged or charging it to the end and leaving it damages the battery. The damage is irreversible and represents degradation of that battery.

However, sometimes it happens that the battery can actually still be saved by undergoing regeneration by verifying the cells, replacing them with used ones or replacing them with others. To carry out this process, you need top-of-the-line equipment. Such equipment diagnoses the technical condition by charging, discharging the battery and checking the internal resistance under load. Once this is done and the right working cells are selected, they can be arranged in the correct order by their power. Any minimum cool down of one of the sectors will lead to an error and the battery controller by incorrect volts and resistance values.

Some battery regenerating companies form and start business based on the belief that it only takes one cell for such battery to still perform well up to two years. As a result of such business, the customer pays a price equal to half of a new battery and the car is left with a battery that is damaged even more. If awareness of the care you need to take of a battery was greater, and new owners were informed about it by the car dealer, fewer batteries would be used up so quickly. It’s not indifferent to the environment either. The engineer that created the battery software inputs the information and sets the limitations of the particular cell. This data is given to him by a machine, which is used to test the cell in question, and he selects, for example 30 identical pieces that will fall within the same parameters (up to how many volts it can be charged, discharged and how much resistance there can be in the load, as well as the maximum temperature inside). Any deviation from this data in the battery will report an error, which the service will likely read as a signal to replace the entire battery including the controller. The vehicle owner will continue to remain in the dark. Only an independent service like ours, which has the needed conditions, remanufactures the components and has a specific devices is able to accurately diagnose the battery. The customer is given a printout with estimated efficiency of the battery and parameters such as the internal capacity of a given sector, the marginal value of charge, discharge, internal resistance and the temperature at the load of a given cell. It is unthinkable to me that any service would replace used cells, in a used battery with new once. But unfortunately, you can come across this practice and it can waste you a lot of money

Hybrids have been getting worse and worse on the market, because they are now on the road for longer and longer. Manufacturers are learning from their mistakes how to create better batteries and how to make them more efficient,for example by cooling them with air conditioning. Because of the modern approach, batteries are stored in aluminum containers. The problem is that it is common for a car to show up at the repair shop after an accident with a state of charge of 30-40% during a bump. It is left to be repaired, but most repair shops only take care of an external issues. Then, there often is a moment when you start the car, which is discharged and there is no possibility of charging. The safest value of state of charge is about 50%, it is worthwhile in such cases to go to a specialist first, who will be able to obtain it. He will also store it in suitable conditions until the hv system is repaired.

We also offer our customers the option of repairing hybrids by remanufacturing hybrid batteries with postal or courier shipping. The customer can send us his faulty electric or hybrid battery and we will fully remanufacture the customer’s hybrid battery and send it to the address indicated by the customer throughout Poland, at the request of our customers. We can also send the repaired battery abroad.