The nickel metal hydride charge can reach about 1.5V.

In addition to the voltage, then the capacity and discharge rate. The capacity of the battery is measured in mah (milliampere-hour) and the discharge rate in C. As for the C number, let's make it simple. 1C is different for different capacity batteries. 1C refers to the battery discharge rate of 1C can continue to work for 1 hour. Example: if the battery of 2200mah capacity keeps working for 1 hour, then the average current is 2200ma, that is, 2.2a, 2.2a is the 1C of this battery. If the above nominal 30C (almost all the batteries in the market have more or less false standard). So the maximum discharge current of this battery is 2.2A*30=66A. This means that the battery is safe for use with the 66A (although the normal airplane model can't release such a strong current, right?). ).

Another example is that the 1C in the capacity of 2200mah is 2200ma, or 2.2a. If the above nominal 30C, then the maximum discharge current is 2.2a *30=66A, the maximum discharge current of this battery is 66A. However, the battery above works at 66A, discharging at 30C, the theoretical maximum current working use is 60/30=2 minutes. In a word, the smaller the number of C, the longer the maximum discharge time of the battery (I am not asking you to buy a small number of C batteries to improve the endurance, in fact, a large part of the aircraft's endurance depends on your driving habits ~). So you can't just buy a battery and look at the C number. A battery with a small C number may also discharge more than a battery with a large C number, because it is also related to the capacity of the battery. You could also say that larger C Numbers are more robust. If you use a small number of C battery large current discharge the battery will be a few times broken.

We are now used on the aircraft model lithium battery called "lithium polymer battery", commonly referred to as lithium battery. Because the quality of the brands varies widely, so do their prices. The following example shows how to use lithium battery correctly. Normally, the 11.1v remote control aero-model lithium battery is composed of 3 lithium batteries in series (the most popular 3S battery, figure 1), that is, the voltage of each battery is 3.7v. The voltage marked on lithium batteries of models, mobile phones and cameras is called marked voltage, which is obtained from the average working voltage.

The actual voltage of a single lithium cell is 2.75~ 4.2v, and the capacity of the lithium battery is the amount of electricity obtained by discharging 4.2v to 2.75v. Remote control aero-model lithium batteries must be kept in the voltage range of 2.75~ 4.2v for use. Such as remote control model aircraft lithium battery voltage is lower than 3.7 V is excessive discharge, belong to severe excessive discharge less than 2.75 V, the battery is fatal damage), expands the lithium electricity, internal chemical liquid crystal, the crystal may be pierced internal structure layer built into short circuit, even let the li-ion battery voltage to zero, then the battery scrap, if not appear afore-mentioned serious results, crystal will make battery capacity and discharge rate is greatly reduced, so that the value of the battery discount clasp, so good habits at ordinary times is to increase the battery life way! The remote control aero-model lithium battery voltage is higher than 4.2v, which is an overcharge, and the internal chemical reaction is too fierce. Lithium battery will blow up and expand, and if it continues to be charged, it will burn or even explode (figure 2).

Therefore, both overdischarge and overcharge will cause devastating damage to lithium batteries. Therefore, we suggest using the regular charger in line with the safety standard to charge the battery, and it is strictly forbidden to modify the charger without permission, which may cause serious consequences!

Lecture one -- charge

1. Charging current: the charging current shall not exceed the maximum charging current specified in the specification (normally 0.5~ 1.0c or below), and the current of 1-2a is generally set. Charging at a current higher than recommended can cause battery chargability, mechanical performance and safety problems, and may lead to heat or leakage. At present, it is recommended not to use 5C to charge the model aircraft battery currently sold in the market, so as not to affect the battery life.

2. Charging voltage: the charging voltage shall not exceed the specified limit voltage (4.20v/single battery), and 4.25v is the maximum limit of charging voltage for each section. (direct charging is strictly prohibited, or the battery may overcharge, and users will be liable for the consequences caused by wrong use of the battery. Figure 2 is the best example.

3. Charging temperature: the battery must be charged within the range of the ambient temperature specified in the product specification, otherwise the battery is vulnerable to damage. When the battery surface temperature is abnormal (refers to the battery surface temperature exceeds 50℃), should immediately stop charging.

Lecture two -- discharge

1. Discharge current: the discharge current shall not exceed the maximum discharge current (the formula is "milliamps ÷1000 times the number of C", which is the limit discharge current of the battery. However, in the context of various imaginary C Numbers, the theoretical current is generally not up to ~~~), too much current discharge will lead to a sharp decrease in capacity and lead to overheating and expansion of the battery. Play big bypass friends attention ~~~ use model friends popular words is don't put the battery too fierce, so it is not put, the battery life (discharge rate, capacity) will obviously decline ~~~

2. Discharge temperature: the battery must discharge within the operating temperature range specified in the specification. When the surface temperature of the battery exceeds 60℃, it shall be temporarily suspended until the battery is cooled to room temperature.

3. Overdischarge: overdischarge will cause devastating damage to the battery, so it is best not to make the voltage of single battery lower than 3.7v when discharging.

Lecture three -- storage

Batteries should be stored in a cool environment, long-term storage of batteries (more than 3 months), recommended to be placed in the temperature of 10-25℃ and low temperature without corrosive gas environment. During long-term storage, the battery is charged and discharged every 3 months to maintain the battery activity and ensure that the voltage of each cell is within the range of 3.85v.