Lead-acid accumulators are the oldest and most common type of secondary cells. There are still some problems to solve. Grid corrosion in sulphuric acid is one of them, which reduced lifetime of lead-acid accumulators. The first part of work is focusing on a general theoretic description of lead – acid accumulators. Following is a description of the workstation and method of measuring. The final part of the text is measuring on an experimental cell.

This master’s thesis deals with lead acid battery in hybrid electric vehicles which operating at mode of partial state of charge (PSoC). In this mode, there is often a negative electrode degradation mostly due to irreversible mechanism of suphation. The idea of this work is detect ideal value of mechanical pressure exerted on active mass of negative electrode in combination with additives to prevent mechanism of sulphation and lead to increased cycle life of lead acid battery.

The most used type of the secondary energy sources is the lead-acid accumulator today. It is also used as a propulsion in hybrid electric vehicles. Functional principle stayed same as in foundation time, only parameters are still improving. Lifetime of lead-acid accumulator is influenced by used separator. The work deals with the description of properties of lead acid separators, methods of testing and evaluation of the suitability for use.

This work aims on acumulators for hybrid vehicles and deals particularly with research of inner-resistance of the lead-acid batteries. There is a brief characterization of hybrid cars in first part of the tesis. Second part is dealing with design of experimental measurement setup for measurement of lead-acid electrochemical cells. Set of experiments on several cells was performed, description of experiments and results in graphical form are present.

Main goal of the diploma thesis is to examine lead-acid accumulator and to study cycling modes in different setups. Theoretical part describes history, types of maintenance-free batteries, degradation mechanisms and possibilities to remove them. Practical part involves the production of electrodes and experimental cell, composition of active mass and measurement of internal resistance. Different configurations for deep cycling are researched as well. The results of the work are summarized and commented at the conclusion of the thesis.

Hybrid electric vehicles use lead acid batteries operating under partial charge. Battery life of these batteries is dependent on the speed of development of lead sulphate (PbSO4) to the negative electrodes. Different admixtures are affected battery life. This work deals with the influence of titanium dioxide on the negative active material in lead battery. Mainly devoted to the influence of the applied pressure.

Lead-acid batteries are most used secondary electrochemical power sources. Their basic principle has remained the same for several years; only the operating parameters are in development. Lead-acid batteries are used in hybrid electric vehicles (HEV), which operates in the partial charge PSoC. Sulphation is one of the possible failures lead-acid batteries in the HEV, especially the negative electrode. By adding additives to the negative active mass can reduce the rate of sulphation and increase ability to accept an electrical charge by negative electrode.

This thesis focuses on the limitations of degradation mechanisms of Lead-Acid batteries, which significantly contributes unequal distribution of current (and therefore internal resistance, charge passed and power loss) on the surface of the electrodes of Lead-Acid battery. The unevenness of distribution of these parameters significantly influences the distribution of current tabs on the electrodes. In this work it was developed realistic model of Lead-Acid battery cell with plate electrodes with different variants of the distribution of current tabs. Measured results obtained in this model were compared with the results found out from the mathematical simulations. Through these simulations, it was possible to take a look deeply into the processes and changes in the electrodes of Lead-Acid batteries during discharge. Goal of this work was for predefined variants of positioning of the current tabs to simulate distribution of current, internal resistance, charge passed and power loss during discharge. Another goal was to compare the different variants and to find the optimal variant of current tabs positioning based on minimizing of unevenness of examined variables distribution.

Användandet av solceller ökar kontinuerligt i Sverige och effekten som genererasav solcellerna förvaras oftast i bly-syra batterier. Dessa batterier har en dåligpåverkan på miljön eftersom det krävs mycket energi och miljöfarliga material såsom bly och svavelsyra för att tillverka dessa batterier. Östersjökompaniet AB ochmånga av dess kunder inser vikten av ett hållbart tänkande och var intresseradeav att veta om det var möjligt att maximera livslängden av dessa batterier. Underarbetets gång analyserades olika metoder för upp- och urladdning av batterier somkan påverka ett batteris livslängd och hur man kan bära sig åt för att optimera det.En laddningskontroller användes för att optimera laddningen av batteriet. För attberäkna laddningsnivån i batteriet användes metoden ”Extended voltmeter”. Enprototyp som kunde ladda batterierna på ett optimalt sätt, varna då batterietsladdningsnivå blev för låg samt en användarvänlig applikation för övervakning avbatteriet konstruerades. Ett batteris beräknade livslängd är ingen exakt vetenskap.Enligt studier kan livslängden av ett batteri fördubblas om det laddas upp ochladdas ur på ett optimalt sätt i jämförelse med då det laddas ur helt. / The use of solar cells is continuously increasing in Sweden and the powergenerated by the solar cells is usually stored in lead acid batteries. These batterieshave a bad impact on the environment as much energy and environmentallyhazardous materials like lead and sulfuric acid are required to manufacture thesebatteries. Östersjökompaniet AB and many of its customers realize the importanceof sustainable thinking and were interested in knowing if it was possible tomaximize the lifetime of these batteries. During the course of the work, differentmethods of battery charging and discharging were analyzed that could affect thebatteries lifetime and how to take care of them to optimize them. A chargecontroller was used to optimize the charge of the battery. To calculate theremaining state of charge in the battery, the Extended voltmeter method was used.A prototype that was able to charge the batteries optimally, warn when the batterycapacity became too low, and a user-friendly application for battery monitoring wasdesigned. The calculated lifetime of a battery is not an exact science. According tostudies the lifetime of a battery can be doubled if it is c

The electrification of personal transport vehicles is one of the strategies to counteract global warming and dependance on fossil fuels. Diesel powered cars are already prohibited in several big cities and the prices for fuel are constantly climbing. Even so, electric cars are still a premium that not everyone can afford as they could an older ICE-car. This means that there can be a gap in the near future were the Swedish working- and middle class can neither afford a new EV nor refuel their combustion engine car. This thesis investigates the possibilities and challenges of electric conversion of an existing, (used) combustion engine car as an alternative to buying a new electric car. The conversion is meant to be a DIY-project that can be carried out by anyone with the capacity to learn all the skills necessary and with sufficient funds to own a car in the first place. Parts of or the whole project can be outsourced to machine shops or similar, if there are areas where knowledge or equipment of the builder are insufficient. This type of conversion proves to be highly modular where the selection of both car and components depends on budget, time, and knowledge. Brushed DC motors offer reliability at a low cost, but with relatively low efficiency. A three-phase induction motor will be a more costly option, but with the benefit of higher efficiency and power. The batteries that are deemed appropriate for the conversion are lead-acid and lithium-ion batteries. Lead-acid batteries are robust and have a low cost. Their low energy density will however result in a higher weight making this type of battery best suited for a small car with short range. Lithium-ion batteries, which are used in commercial EVs, have a high energy density and lower weight. They come at a high cost however, and they require individual monitoring of the cells’ voltage to prevent potential failure. The converted car will have to be registered as a modified vehicle in order to legally be used in Sweden. The original total weight of the car cannot be exceeded during the conversion and because of this, a car with low curb weight and high max load is preferable as a starting point. / Den pågående elektrifieringen av personlig transport är ett av verktygen för att uppnå en hållbar utveckling. I samband med detta stiger bränslepriser och förbud mot dieseldrivna bilar finns numera i flertalet städer. Trots detta är elbilar fortfarande mycket dyra i inköp. Elkonvertering av befintliga (begagnade) bilar kan vara både ekonomiskt och ekologiskt gynnsamt då resultatet blir en cirkulär ekonomi och minskat behov av fossila bränslen, samtidigt som bilägaren ej behöver betala för dyrt bränsle. Detta examensarbete kartlägger möjligheterna och utmaningarna kring elkonvertering av enbegagnad bil med förbränningsmotor som alternativ för att köpa en ny elektrisk bil. Konverteringen skall vara ett DIY-projekt som kan genomföras av alla som har kapaciteten att lära sig de färdigheter som krävs samt har finansiella möjlighten att äga en bil. Delar av eller hela arbetet kan även lämnas bort till en mekanisk verkstad om byggaren saknar kunskap eller utrustningen för att genomföra projektet. Att utföra en sådan konvertering visar sig vara högst modulärt där val av bil eller komponenter behöver fattas utifrån budget, tid och kunskap. Kolborst-DC motorer erbjuder pålitlighet till ett lågt pris men har förhållandevis låg verkningsgrad. Trefas AC motorer innebär högre kostnad men erbjuder högre effektivitet och mer effekt. De batterier som bedöms lämpliga för konverteringen är bly-syra batterier och litium-jonbatterier. Även här skiljer sig kostnad och prestanda. Bly-syrabatterier är robusta och innebär lägre kostnad, men har låg energidensitet och resulterar i hög vikt. De lämpar sig därför för mindre bilar med kort räckvidd. Litium-jonbatterier, som används kommersiellt i dagens elbilar, har hög energidensitet och lägre vikt. De är dock ett mer kostsamt alternativ och kräver cellövervakning för att förhindra potentiellt haveri. Bilen kommer behövas registreras som ombyggt fordon för att lagligt kunna brukas i Sverige. Viktigt är att bilens ursprungliga totalvikt ej överskrids, varför en bil med låg tjänstevikt och hög maxlast är att föredra som utgångspunkt för konverteringen.