Do you know how to test the battery of electric vehicles and repair electric vehicles? Ask a profess

If there is no deformation of your battery (that is, it is charged and bulging), if it is not deformed, one of the batteries must be broken (broken), it is rarely broken two, and it is impossible to break three, that is to say, there are three pieces that are good, you can say to the maintenance department to replace one piece first, only spend about 20-30 yuan, but this one must be old, it cannot be new, and the 20-30 yuan is also earned by him, because the old battery is also replaced by others ( Generally, a set of batteries are replaced, I said, it is impossible for all four pieces to be broken), he can only be sold as an old battery, you spend 20-30 yuan on this piece, so it is said that he makes more money, and he can still sell your old battery.

According to what you said about the charger, as long as the polarity is correct, it must be matched, that is, you have used it once and there is no abnormality, which means that there is no problem with the charger.

You said that the second master said that there are three batteries broken, he must lie to you, want you to change a set of batteries, if you change, then he will make a lot of money, because you not only give him money for new batteries, he also earns your old batteries, because some batteries are good, he can also change (sell) to others.

You can go to the first master and it seems that he is "a little bit more realistic". You change an old battery, maybe it's better than a new set, really, trust me, because I'm very practical in business.

I am engaged in the sales and maintenance of electric vehicles.

You should listen to the first one, your battery is indeed broken. should be replaced.

You can run 20 kilometers is a battery broken, it is recommended to replace an old battery, it is not cost-effective to replace a new one, according to the age of the battery, it is almost all replaced in a year.

No, what do they eat?

If a battery is running out, the symptoms are: when fully charged, the driving distance is significantly shorter than before, and the electric vehicle shows that the number of charging compartments is unstable. If you charge when there is no power, the charger will be displayed as fully charged if it is not charged for a while.

2. Unplug the main power plug on the battery compartment, and then remove the battery compartment shell.

Multimeter use.

Adjust to DC 50V gear, two meter pens (red +, black -) respectively contact the + - pole of each battery, the standard is 12V voltage, a battery is lower than this voltage, it means that the battery is aged and broken. Some single batteries also show 12V just after being fully charged, but the storage current is insufficient, and there is a special battery measuring instrument to detect it.

If you don't have a measuring instrument, you can connect a large load, for example, a 12V100W bulb, connect the multimeter to +- pole, and then connect the bulb, at this time, look at the reading on the meter, below 10V, it means that the battery is broken.

1. Judge the new and old batteries by the external packaging of the battery.

2. Check whether the outer packaging is damaged or has been opened.

3. Check the appearance of the battery itself, and observe whether there are scratch marks and whether there are rust on the terminals of the positive and negative poles.

4. Check whether there is an anti-counterfeiting label on the battery shell, whether the production date is relatively old, whether the manufacturer's relevant information marks are complete, and whether the writing is clear and complete. If there is 1 point or more in the external packaging of the battery, it is considered that the battery is an old battery sign, and there may be quality problems.

5. Install the battery that has just been fully charged to the electric vehicle, start the power supply of the electric vehicle, suddenly accelerate the electric vehicle during driving, observe the change of the fuel gauge pointer, and the pointer of the fuel gauge only falls less than half a grid during the acceleration ride, then judge that the battery is brand new or has good performance.

If it is a new battery, when it is to be tested, more than 85% of the capacity is a qualified battery.

The indicators of battery detection are generally voltage, internal resistance, and capacity. For example, a 12-volt 10-ampere-hour battery is fully charged with voltage. The internal resistance is less than 1 ohm. The discharge time at 1 amp is more than 8 hours. Then this battery is qualified.

If the nominal voltage of the electric vehicle battery exceeds 48V, it is unqualified.

In the national mandatory standards, in order to ensure the safety of electric bicycles, the nominal voltage of the battery should not be greater than 48V. However, in real life, some electric vehicle specialty stores have also adopted the method of increasing the battery capacity in order to allow the new car to run more kilometers.

The Consumer Association reminds that increasing the battery capacity without authorization will make the electric bicycle adjust the speed, but for consumers, the most direct harm is the danger of not being able to brake the car during driving.

When the battery is old and lost, consumers should go to the regular after-sales maintenance point to replace the battery, and the purchase of new batteries should also pay attention to quality and matching, rather than simple comparison and random selection.

Different electric vehicles produced by different manufacturers will have certain battery matching differences, the most suitable battery is the first choice for replacement, inferior or unmatched batteries may bring certain safety hazards.

If it is a new battery, when it is to be tested, more than 85% of the capacity is a qualified battery...

1. Rated capacity of battery:

It is the battery capacity specified in the national standard. The unit is expressed in Ah, which stands for ampere-hour, which reflects the amount of power stored by the battery.

The larger the value, the more power is stored, and the capacity of electric vehicle batteries on the market is average.

All are 10Ah and discharged at a constant current of 5A for 120 minutes.

2. The actual capacity of the battery:

Reflects the actual storage capacity of the battery, and the unit is expressed in Ah ampere-hours. The greater the ampere-hours, the battery capacity.

The larger it is, the longer the EV's driving range. During use, the actual capacity of the battery will gradually decay.

The national standard stipulates that the actual capacity of the newly manufactured battery is greater than the rated capacity value for qualified batteries. Such as the current market power.

The battery of the moving bicycle should be discharged at a constant current of 5A for more than 2 hours (120 minutes) and more than (2 hours for 5A).

10ah。It is equivalent to an electric car driving on a flat road for more than 2 hours continuously.

3. Discharge cycle life:

It refers to the number of cycles when the battery is charged and discharged until the battery capacity is reduced to 70 rated capacity, and then discharged to a certain depth after sufficient charge. The more battery cycles, the longer the lifespan, electric.

The cycle life of the bicycle battery is not less than 350 times, and less than 350 cycles is an unqualified battery. It's on the market right now.

In general, e-bikes are used to commute, commute to or from work or pick up and drop off children to school within the city limits of each.

Drive continuously for about 1 hour a day (about 25 kilometers), which is equivalent to about 180 battery cycles in a year, if it is a qualified battery, it can be used for nearly two years, and the battery capacity is rated at 70, which is equivalent to electricity.

The train can also travel for 70 minutes continuously, about 30 kilometers.

4. Rated voltage of the battery and working voltage of the battery pack

The battery voltage value specified in the national standard is the rated voltage, which is expressed in V volts, and the voltage value of each grid of lead-acid battery is.

2V, the electric vehicle battery on the market is only 6V and 12V per grid. Each 6V battery is connected in series by 3 cells in a single compartment.

The 12V battery is composed of 6 cells connected in series. Most e-bikes use 36V batteries, and 6 6V batteries or 3 12V batteries are connected in series to form a battery pack.

The working voltage of the battery pack refers to the voltage value of the battery pack when it actually outputs electric energy, and the working voltage of the 36V battery pack.

Generally, it is between 41V and below, which is called over-discharge or under-voltage of the battery, which is easy to damage the battery pack and affect the service life of the battery.

The new battery cell standard should be 13-14V