Introduction：
Have you ever wondered why the range of electric vehicles is getting worse? The answer may be hidden in the "voltage difference" of the battery pack. What is pressure difference? Taking the common 48V lithium iron battery pack as an example, it consists of 15 series of batteries connected in series. During the charging process, the charging speed of each series of batteries is not uniform. Some "impatient" individuals are fully charged early, while others are slow and leisurely. The voltage difference formed by this difference in speed is the main culprit of the battery pack being "not fully charged or discharged", directly leading to a significant reduction in the range of electric vehicles.
Countermeasures: The "Offensive and Defensive Game" of Two Balanced Technologies
Faced with the threat of voltage difference to battery life, battery balancing technology has emerged. Currently, it is mainly divided into two camps: passive balancing and active balancing, each with its own unique "combat mode".
（1） Passive Equilibrium: The 'Energy Consumption War' of Retreat as Progress
Passive equilibrium is like a 'master of energy consumption', adopting a strategy of retreat as progress. When there is a voltage difference between battery strings, it will consume the excess energy of the higher voltage battery string through heat dissipation and other methods. This is like setting obstacles for a runner who is running too fast, slowing it down and waiting for the low voltage battery to slowly "catch up". Although this method can to some extent narrow the voltage gap between battery strings, it is essentially a waste of energy, converting excess electrical energy into heat and dissipating it, and the waiting process will also prolong the overall charging time.
（2） Active Balance: Efficient and Accurate 'Energy Transport Technique'
Active equilibrium is more like an 'energy transporter', adopting proactive strategies. It directly transfers the electrical energy of high-energy batteries to low-energy batteries, achieving the goal of "bridging strengths and compensating for weaknesses". This method avoids energy waste, balances the voltage of the battery pack more efficiently, and improves the overall performance of the battery pack. However, due to the involvement of complex energy transfer circuits, the cost of active balancing technology is relatively high, and the technical difficulty is also greater, with more stringent requirements for the stability and reliability of the equipment.
Prevention in advance: "Accurate escort" of capacity tester
Although both passive and active balancing technologies can alleviate the voltage difference problem to some extent and improve the range performance of electric vehicles, they are always considered as "remedial measures after the fact". To grasp the health of batteries from the root and effectively prevent voltage differences, precise monitoring is the key. During this process, the capacity tester became an indispensable 'battery health expert'.
The battery capacity tester can detect key data such as voltage, capacity, and internal resistance of each string of the battery pack in real time and accurately. By analyzing these data, it can sensitively detect potential voltage differences in advance, just like installing a "warning radar" for a battery pack. With it, users can intervene in a timely manner before battery problems worsen, whether it is adjusting and optimizing charging strategies or evaluating the implementation effect of balancing technology. The capacity tester can provide scientific and accurate basis, truly nip battery failures in the bud, and keep the range of electric vehicles at an ideal level.
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Jacqueline: jacqueline@heltec-bms.com / +86 185 8375 6538
Nancy: nancy@heltec-bms.com / +86 184 8223 7713
Post time: Jun-30-2025