Technical points of Refitting Vehicle lead acid battery into lithium ion battery
1. When refitting, you should consider the problem of volume and space. Under the same capacity, the volume of lithium-ion battery is only half of that of lead-acid battery, so it can certainly be installed. However, attention should be paid to some shape and packaging problems. After all, the space on the car is not necessarily in the same direction as the battery. You should consider fixing and reliable to prevent vibration and falling. And if the economic conditions allow, of course, it is hoped that the larger the capacity of the modified lithium-ion battery is, the better. Therefore, it is necessary to make full use of the upper space and select a reasonable shape of the battery for layout. If the same capacity is replaced, because the remaining space is large, when replacing, we should find something to fill the extra space to prevent the lithium-ion battery from sloshing and falling off when driving.2. When disassembling the battery, although the output of the battery is positive and negative lines, which is very simple, it should also be removed one by one, wrap the exposed cable ears with adhesive tape, and then mark with ± mark. When installing the battery back, the positive and negative wires should be connected back one by one, so as to prevent the positive and negative wires from being reversed or accidentally causing the positive and negative electrodes of the battery to be short circuited Security issues.
3. When buying lithium-ion battery, it's better to let the business match with the same or similar plug terminal. If the plug shape is different, some may need to re press the wire ear or weld, or even change the line. It is necessary to pay attention to the current size to select the specification size. It is better to put a multimeter DC, and re measure the voltage when wiring to prevent the positive and negative reversal. Remember, the positive and negative poles must be placed separately, do not carry out negative grounding and other operations.
4. If the battery is replaced and the motor and controller are increased, it is necessary to consider whether the main circuit should be thickened. You can check the electrician's manual to see how many square wires can pass through how many amperes. If the original car's wire is thin, it will also leave hidden dangers, and the efficiency and power effect will be discounted.
5. Lead acid battery to lithium-ion battery, charger must be changed to lithium-ion battery dedicated, lead-acid battery internal resistance is large, general charger output voltage to high, and many have pulse charging function, so lithium-ion battery charging may be overcharged, because of protection board protection, charging will cause charger output voltage setting abnormal, backward monomer may Damage caused by failure to fill. If it happens that the protection plate is broken, such high-voltage charging, it is easy to cause explosion.
6. If there are conditions, it can be considered to change the under voltage and over-voltage protection range of the controller. The lead-acid battery is 2 V, 6 of which form 12 V battery. The lower limit of discharge should be controlled above 10.8 v. However, the nominal voltage of ternary lithium-ion battery is 3.7V, and the actual voltage of three series is only 11.1v, but the lower limit of discharge can reach 9V. If four batteries are connected in series, the lower limit of discharge is 12V. If the threshold protection voltage of lead-acid battery is continued to be used, part of the power will not be released effectively, which reduces the advantages of lithium-ion battery.