As FPV drone enthusiasts, we are always looking for ways to enhance flight performance. One game-changer in the FPV community has been the introduction of LiHV batteries. In this blog post, we’ll explore what LiHV batteries are, why they have become popular, how they compare to traditional LiPo batteries, and the pros and cons of using them.
What Are LiHV Batteries?
LiHV stands for Lithium High Voltage. These batteries are a variation of traditional LiPo (Lithium Polymer) batteries but with a key difference in chemistry and voltage. While standard LiPo cells are charged to a maximum of 4.2V per cell, LiHV cells can be charged up to 4.35V per cell. This higher voltage translates into several performance benefits, making LiHV batteries an attractive option for certain types of FPV drones.
LiHV and LiPo Differences
Voltage
The primary difference between LiHV and LiPo batteries is the maximum voltage. LiHV cells charge up to 4.35V compared to 4.2V for LiPo cells. In FPV drone motors, the maximum RPM is proportional to the voltage applied. LiHV batteries provide a higher voltage, leading to increased thrust and faster speeds. For racing drones or high-performance acrobatic drones, this can be a significant advantage, offering quicker response times and more powerful maneuvers.
Weight and Capacity
LiHV batteries tend to have a slightly higher energy density, which means they offer more power without a significant increase in weight or size compared to equivalent LiPo batteries, potentially translating to longer flight times. Additionally, due to the higher voltage, the C rating of LiHV tends to be slightly higher than LiPo for the same size battery.
Compatibility
Despite the difference in maximum voltage, LiHV batteries are generally compatible with most FPV drones that use LiPo batteries. This makes it simple for drone pilots to switch to LiHV without needing to upgrade hardware.
Charging Requirements
Charging LiHV batteries requires a charger that supports the higher end voltage. While many modern chargers do, it’s essential to verify this before attempting to charge LiHV batteries. You can safely charge a LiHV with LiPo settings, but you won’t be using the LiHV battery to its full potential.
These chargers that I recommend can all charge LiHV batteries: https://oscarliang.com/choose-lipo-battery-charger-power-supply/#Top-LiPo-Charger-Recommendations
LiHV Batteries Testing
For this test, I selected LiHV and LiPo batteries with very similar specifications to focus on the differences between these battery types:
- GNB 2S 550mAh 90C LiPo
- GNB 2S 550mAh 100C LiHV
You can check their specs here: https://oscarliang.com/whoop-toothpick-lipo-battery/#2S-LiPoLiHV
Discharge Performance
So, how does LiHV compare to LiPo in terms of discharge performance?
In my testing, LiHV showed superior performance regarding discharge rate, with lower voltage sag under load, particularly in the first half of the pack. However, this advantage was less noticeable towards the second half of the pack. Another interesting fact is that for the same weight, the LiHV battery offers higher capacity, making it a more energy-dense battery than a typical LiPo.
- LiPo (GNB 2S 550mAh 90C LiPo):
- Weight: 30.2g
- Measured Capacity: 525mAh
- LiHV (GNB 2S 550mAh 100C LiHV):
- Weight: 29.3g
- Measured Capacity: 558mAh
These results indicate that LiHV batteries not only provide better initial performance but also pack more energy for the same weight.
Lifespan Comparison
Does LiHV have a shorter lifespan than LiPo?
In another test, I fully charged both LiHV and LiPo batteries to their maximum voltage at 2C, then discharged them at 20C until 3.3V per cell, repeating this for 100 cycles. My testing suggests that LiHV loses its ability to hold charge faster than LiPo with usage. After 100 charge cycles, LiHV loses about 5.4% of its original capacity while LiPo only loses 3.8%.
| LiPo | LiHV | |
| Cycle #0 | 525mAh | 558mAh |
| Cycle #50 | 515mAh | 545mAh |
| Cycle #100 | 505mAh | 528mAh |
* Capacity was measured by discharging the battery slowly at 2C from fully charged until 3.3V per cell.
This test took me nearly 100 hours to complete! If you find it useful, please consider subscribing to my Patreon so I can continue providing this type of content: https://www.patreon.com/oscarliang
When it comes to discharge performance, the difference is much smaller, as shown in the discharge graphs below. The main degradation seems to be in how much charge these batteries can hold—the capacity decreases with usage.
LiPo:
LiHV:
One thing we have yet to verify is how these batteries’ performance is impacted over time when not in use. I believe LiHV and LiPo batteries naturally lose their performance over time, but usage definitely accelerates this process. However, usage doesn’t seem to impact their discharge performance as much as I expected. Voltage sag is similar after 100 charge cycles, but the reduction in the charge they can hold is noticeable.
The conclusion here is, don’t worry too much about charging and discharging your batteries! While they are sitting in your drawer doing nothing, their performance slowly degrades anyway. You should use them as much as you can to get the most out of them. Get out there, fly, and have fun!
Can You Charge LiPo to 4.35V?
Absolutely NOT. You should NEVER charge a standard LiPo battery to 4.35V per cell. Traditional LiPo batteries are designed to be charged to a maximum of 4.20V per cell. Charging them beyond this voltage can lead to several serious issues, including overheating, swelling, or even catching fire. Overcharging also reduces the lifespan of the battery and can cause permanent damage.
Can You Charge LiHV to 4.20V?
Yes, it’s safe to charge a LiHV battery to 4.20V per cell, as the maximum voltage you can charge it to is 4.35V per cell. However, you are only using 90% of its capacity.
LiHV Is Not for Everyone
There’s a concern about the longevity of LiHV – its performance degrades faster than a typical LiPo. Also, as you go up in cell count, the benefit of the higher voltage becomes smaller. Therefore, LiHV is mostly popular for micro drones that uses low cell count batteries, such as Tiny Whoops and 2S Toothpicks, where the higher voltage can make a noticeable difference.
Final Thoughts
LiHV batteries have become a popular choice in the FPV drone community for their ability to provide longer flight times and enhanced performance, especially for micro drones. While they offer several advantages over traditional LiPo batteries, it’s important to recognize the charging requirements and potential lifespan trade-offs. For drone enthusiasts looking to push the boundaries of their flying experience, LiHV batteries are definitely worth considering.
For LiHV battery recommendations for micro drones, check out this post: https://oscarliang.com/whoop-toothpick-lipo-battery/
As always, when working with high-performance batteries, safety should be a top priority. Ensure you use compatible chargers and follow best practices for battery care and maintenance to enjoy the benefits of LiHV batteries while keeping your equipment and yourself safe.
