Evolution of Charging Trends

A defining technology of the future is the evolution of the charging trends for electric vehicles. 

In the decades between the 1960s and the 1990s, Battery charging technology started with incremental changes in the 1960s where chargers were predominantly constructed with steel and copper. The

Their unsealed, heavy, and cumbersome design were plagued with efficiency issues. 

The next evolution came like lightning with the Lithium-Ion revolution during the 2020s, driven mainly by the adoption of lithium-ion in electric vehicles. By 2023, the ripple effects of the lithium-ion paradigm were evident across multiple industries. A significant catalyst behind its widespread adoption was its superior scalability compared to its predecessor, the lead-acid battery.

The magnitude of its advantages becomes evident when we delve into the numbers:

• Energy density – Modern electric vehicle lithium-ion battery packs boast an energy density of 450 Wh/L. When contrasted with the 70 Wh/L offered by lead-acid batteries, we see a remarkable 500% surge in energy density.

  • Additionally, considering the 700% growth in energy density compared to the first generation of EV lithium-ion battery packs in 2008, it’s evident there is still untapped potential.

• Cost dynamics – On the cost front, lithium-ion demonstrates an encouraging trajectory. As adjusted for specific industry applications and production volumes, consider the average cost of lithium-ion battery packs:

  • $1,000/kWhr in 2011

  • $150/kWhr in 2022

  • Although supply chain disruptions have tempered this decline, historical data signals a convergence with the $100/kWhr mark typical of lead-acid batteries

• Charging capabilities – Lead acid risks permanent capacity degradation and reduced lifespan if not fully recharged. Lithium is superior in almost every aspect of charging, being faster and more efficient (less energy loss). This edge is underscored by typical charging durations:

  • Flooded lead acid: 8 hours minimum

  • Sealed lead acid: 3-4 hours minimum

  • Lithium: Less than 1 hour is achievable

With the advent of affordable, high-efficiency lithium-ion batteries where charge acceptance isn’t a constraining factor, the spotlight pivots back to optimizing the charging devices themselves.

Current Situation

The technological constraints we currently face include:-

• AC supply – Beyond the limits of residential outlets (1.2 kW in the Americas, 2 kW in Europe), industrial plugs support up to 7 kW. This can further be increased by 3-phase power, achieving up to 22 kW, but there are inherent limitations beyond this.

• DC current – The problems include conduction loss, inherent resistance, and overheating within DC current pathways. The issues can be mitigated by adding more copper and increasing cooling, but only to a certain degree. Efforts to tackle this issue increasingly focus on increasing the DC voltage.

• Onboard charger dimensions – Industries are demanding more power within a constrained space. That makes the charger size a critical factor and increase the need to enhance the power density.

These seemingly distinct obstacles all share a common theme; for each solution, there are multilayered complications. To properly meet these challenges thus demands a multifaceted approach.

Future Charging Trends

By analyzing the issues faced today, we can predict that the trends of tomorrow will likely involve:- 

• Employing soft switching – By reducing the energy losses and electromagnetic interference typical of hard switching, soft switching can markedly boost the charging systems’ efficiency and performance.

• Replacing diodes with active AC-DC rectification – Though essential in traditional charging designs, diodes introduce fixed forward voltage losses. Replacing diodes with active semiconductor switches, or removing them entirely with bridgeless converter topologies, can slash rectification losses.

• Harnessing GaN and SiC for accelerated switching – The integration of Gallium Nitride (GaN) and Silicon Carbide (SiC) enables faster switching and lower switching losses in power electronics. This innovation enables shrinking of passive magnetic components and heatsinks, contributing to a more compact charge system.

• Implementing advanced cooling mechanisms – The deployment of sophisticated cooling methods, whether passive, fan-driven, or liquid-based, maintains component temperatures within ideal ranges, thus maximizing efficiency and extending the device’s lifespan.

• Adopting denser construction principles – By optimizing space within the charger’s design, both horizontally and vertically, power density can be augmented without expanding the physical charger. This approach requires precise engineering to keep components well-protected and insulated.

• Leveraging system integration to simplify design – Integrated systems can decrease system cost and complexity, by removing components, interconnections, and assembly steps.  The charger can be integrated with a DC-DC converter for powering auxiliary loads.  Integrating communications with offboard DC fast charging stations simplifies the overall charging process, and supports “right-sizing” the footprint of the onboard charger with a hybrid of AC and DC charging.

As battery charging technology continues to advance, these strategies are poised to serve as the foundational pillars for the development of the next wave of cutting-edge charging solutions.

Charging the FUTURE: Key Insights

From the modest advances of the 1960s to today’s advancements, battery charging tech has come a long way, with lithium-ion shifting the focus from battery limitations to charger enhancements.

Tackling today’s challenges demands multi-pronged tactics: from harnessing energy efficiency and soft switching to leveraging cutting-edge materials like GaN and SiC and honing construction techniques.

Such an all-encompassing approach, rooted in system integration and innovation, paves the way for tomorrow’s chargers—more potent, proficient, and in lockstep with the future of electrification.

You are a little shocked and overwhelmed by the rapid changes of technology.

You are worried about how to future-proof your business, with the costs and risks involved in managing the process of evolving technology.

We got your back. 

Our mission is to help companies like yours manage the transition to a sustainable and profitable future.

Contact Us.