The correct way to charge lithium iron phosphate batteries: It is recommended to use the CCCV charging method, that is, constant current first, then voltage constant.
It is recommended that the constant current is 0.3 C, the constant voltage is 3.65, or the charging current is 0.3 C during the constant current process. When the battery voltage reaches 3.65V, 3.65. V constant voltage charging is used when charging. Charging stops when the current is less than 0.1C (or 0.05C), that is, the battery is fully charged.
When charging with a constant voltage power supply, the charging current also depends on it. It is recommended not to charge at too high a voltage. After adjusting the voltage, make sure the charging current is less than 0.5C, which is good for the battery.
Generally, the upper limit voltage of charging of the balithium iron phosphate battery is 3.7 ~ 4 V and the lower limit discharge voltage is 2 ~ 2.5 V. The five factors of discharge capacity, median discharge voltage, charging time, capacity percentage constant current and safety are taken into account comprehensively.
Using constant current and constant voltage charging scheme, for lithium iron phosphate batteries, it is more reasonable to set the charging limit voltage to 3.55~3.70V, the recommended value is 3.60 ~ 3.65 V, and the lower discharge limit voltage is 2.2 V ~ 2.5 V.
Application of ternary lithium batteries< /strong>
In the context of "range anxiety" and "range anxiety" in the industry, long battery life has become a key at the center of the number one task of the new energy vehicle industry. There are currently two main technical paths to solvingthis problem, namely ternary lithium polymer batteries and lithium iron phosphate batteries.
Among them, lithium iron phosphate batteries are the research direction of BYD Auto. At first, they were rarely used due to their low energy density and poor low temperature performance. traditional lithium iron phosphate batteries have been outdated. The density limit reaches the level of ternary materials.
Ternary lithium polymer nickel-cobalt-manganese batteries have a high energy density and are currently the most widely used. However, their cost is high if a breakthrough in security can be made, they will always dominate the market. in the future.
Reference for the above content: Ternary polymer lithium battery from Baidu Encyclopedia
Searching for multiple lithium battery charging and discharging solutions< /h3>
The meiTheir lithium battery charging method involves charging until only one battery remains. There is no need to wait for the low battery alarm or automatic shutdown of the mobile phone to start charging. If you wait until it turns off automatically before charging, the cell phone will be charged. The battery voltage will be too low and it may not be charged. You will need it after activation. Since lithium batteries do not have a memory effect, they do not need to be discharged.
Simple and practical solution: make two strings of lithium batteries, first connect 20-30 lithium batteries in parallel, then connect two large batteries in series. The protective panel may or may not be removed. is removed, install two strings of lithium batteries for the protection board, you can also keep the original battery protection board and add twoseries of protective panels.
For voltage output, use a DC-DC module, and for 5V, use a step-down board of 6-12V input and 5V output. The output current is about 3 A, or 1 A. easy to find. Use USB output, used to charge mobile phones. 9-12V can use booster board, 6-9V input, 9V or 12V output, two It is better to separate the prompt board. You can also find one with an adjustable output voltage, but it is not recommended if you set it incorrectly it could burn the equipment. It is best to separate it. 2A, which is almost enough to power the router and the cat. It is best to add independent input switches to all three boards to prevent static power consumption from causing the board to fail.
The charging part uses an 8.4V two-string lithium battery charger, and the forward point uses balance charging.ber 2S to reduce series overload. Balance charging may have to be homemade, but it is also simple. Lithium batteries can be charged independently. There is also a simple and effective solution, using parallel charging and serial discharge connectors. The specific method is to connect the positive and negative poles of two parallel lithium batteries to a 4-core anti-reverse socket. , then connect them in series to the socket. The connection wires must be connected in parallel. Create another outlet and connect them in parallel. The advantage is that the load is absolutely balanced. You only need one lithium charger, which is everywhere. the downside is that charging and discharging cannot be done at the same time and you have to switch manually. But it's a bit inconvenient, but the pros outweigh the cons. Bipolar switch for switchingseries-parallel. The effect is the same, but the wiring is more complicated.
Note: The parallel battery connection wire should be thicker. The battery has a large capacity. If the charging current is small, it will take a long time and the current should not be too small. For example, if the capacity is 10 Ah, the load should not be less than 1 A. Depending on your situation, it should not be less than 2 A. If possible, divide the battery capacity so that you get the capacity of both. the battery packs are as close as possible. For the selection of parallel charging and serial discharge connectors, four-conductor aviation plugs are more suitable. They are a non-reverse connection and can handle excessive current. A set and a half is needed. Simple high-current lithium chargers are hard to find, so you may need to make your own.