Some entry-level RC cars come with a stock 8.4V NiMH battery, which can be replaced with a 2S 7.4V LiPo battery. So, which one provides more power and longer run time for RC cars? Let’s dive into a detailed comparison.
Detailed Base Comparisons
Discharge Power
| Battery | 7 Cell NIMH | 2S Lipo |
| Minimum Voltage | 6.3V | 6.4V |
| Nominal Voltage | 8.4V | 7.4V |
| Fully Charged Voltage | 9.8V | 8.4V |
Compared to an 8.4V NiMH battery, a 7.4V LiPo battery delivers higher discharge power, enhancing the acceleration and responsiveness of RC cars. This is because, although the voltage of a 7.4V LiPo battery is lower, its discharge rate can be significantly higher. Additionally, during the latter stages of discharge, as the voltages of both types of batteries converge, the power difference between them becomes more pronounced.
Running Time
Thanks to the higher energy density of LiPo batteries, a 7.4V LiPo battery can offer more capacity (mAh) in the same volume, resulting in longer runtime compared to NiMH batteries.
Charging Time
LiPo batteries support high-current charging and can be quickly charged using an RC smart charger, often taking only 30 to 60 minutes to fully charge. In contrast, NiMH batteries typically require over half a day to reach a full charge.
Weight and Size
LiPo batteries are lighter. For example, a 5000mAh 7.4V hardcase LiPo battery weighs around 300g, while an 8.4V NiMH battery weighs approximately 500g. Additionally, since the size of NiMH battery cells is fixed, whereas the size of LiPo battery cells can be adjusted during manufacturing, LiPo batteries can be made thinner, resulting in a lower center of gravity. This improves handling and reduces the risk of flipping when RC cars make turns.
Battery Life and Durability
As mentioned earlier, NiMH batteries are somewhat inferior in certain aspects but excel in battery life and durability. NiMH batteries can handle around 500 to 1000 charge-discharge cycles. In comparison, LiPo batteries typically last about 300 to 500 cycles. Furthermore, the internal chemistry of NiMH batteries is more stable, making them more tolerant of abuse. LiPo batteries, on the other hand, can suffer permanent damage if over-discharged or overcharged, shortening their lifespan and reducing their discharge performance.
Summarize
With advancements in manufacturing technology, LiPo batteries have become the mainstream choice for RC hobbies and are now comparable in cost to NiMH batteries. If you plan to pursue RC hobbies long-term, upgrading from NiMH to LiPo batteries and investing in a professional smart RC charger is worthwhile. This upgrade not only enhances the performance of your RC car but also offers greater convenience and reduces potential hassles.
