NiMH Battery Voltage Chart

Are you unfamiliar with RC NiMH batteries on the market? Then you’ve come to the right place. This article provides information on the voltage, size, and discharge performance of NiMH batteries that will be useful to you. In addition, NiMH and Lipo are compared in detail, and you can choose a suitable battery according to these.

Table of Contents

NiMH Battery Voltage Chart

Cell	1s	2s	3s	4s	5s	6s	7s	8s
Rated Voltage(V)	1.2	2.4	3.6	4.8	6	7.2	8.4	9.6
Fully Charged Voltage(V)	1.4	2.8	4.2	5.6	7	8.4	9.8	11.2
Minimum Safe Voltage(V)	0.9	1.8	2.7	3.6	4.5	5.4	6.3	7.2

NiMH is chemically more stable than Lipo, so there is no need to set the storage voltage.

Discharge curve of NiMH battery

The above data are the results tested at ambient temperatures of 25°C, 0°C, -20°C, and -40°C, respectively. As can be seen from the chart:
When the NiMH discharge voltage is lower than 1.1V, its power decreases rapidly. So in practice, we usually set the cutoff voltage of RC cars running NiMH to 0.9V. When it is close to 0.8V, it means that the power is almost exhausted. If you continue to use it, it will cause irreversible damage to the battery.

Besides, the ambient temperature has a great influence on the discharge performance of NiMH. Because the electrochemical reaction of NiMH is related to the ambient temperature. For example:

As the temperature decreases, the reaction rate of the electrode also decreases.
The battery voltage remains constant, the discharge current decreases, and the power output of the battery decreases.
The opposite is true when the temperature rises, that is, the output power of the battery will increase, and the temperature will also affect the transmission speed of the electrolyte.
Temperatures above 45°C can disrupt the chemical balance within the battery, causing side reactions and damaging the battery.

NiMH Battery Size Chart

Series	Diameter(mm)	High(mm)	Capacity(mAh)
AAAA	8.2	40	≤300
AAA	10	43	≤700
AAA	10.1	43	≤1000
AA	13.9	49	≤1600
AA	14.1	50	≤2500
A	16.6	50	≤2500
SC	21.9	43	≤3000
C	25.2	49	≤5000
D	32.2	60	≤11000
F	32.2	90	≤14000

NiMH vs Lipo

NiMH battery

Pros

Low cost
Strong versatility
Safer
Good fast charging performance

Cons

Has memory effect
High internal resistance
Short service life

NiMH batteries cost less and it is more suitable for RC beginners. NiMH batteries have lower energy density. Because it uses water as the electrolyte, it is not easy to burn, and its safety performance is better than that of lithium-ion batteries. So you don't have to worry about problems with the NiMH, and enjoy the RC car to the fullest.

Lipo battery

Pros

Light, small
High energy density
High discharge voltage
Low self-discharge rate
High and low-temperature adaptability

Cons

High cost

Lipo performs better than NiMH. Because of this, the production volume of Lipo in the market gradually exceeds that of NiMH. Lipo has a high C-rate and high voltage platform, which can provide the powerful punch of an RC car. If you want to improve the overall performance of your vehicle, then upgrading the NiMH to Lipo is the easiest way.

Frequently Asked Questions

Q: What is the service life of NiMH batteries?

A: The cycle life of NiMH rechargeable batteries can reach 500 times. They can be used for more than 5 years as long as they are not abused. Although the memory effect of NiMH batteries is small, I still recommend that you try to recharge them after each use, and charge them all at once. This extends the life of the battery.

Q: NiMH or Lipo, which is better?

A: As mentioned above, they each have their pros and cons. If you’re a beginner, NiMH batteries not only save your budget, but the stable chemistry prevents you from abusing them. When you are familiar with RC batteries and want to improve the driving performance of your vehicle, then lipo batteries are your best choice.