There are many factors that are unfavorable to batteries, which mainly occur during the charging and discharging stages.

1. The "two overs" discharge stage is mainly caused by excessive discharge current, that is, long-term discharge exceeding the allowable current value; the second problem of discharge is over-discharge, that is, exceeding the allowable discharge amount of the battery, which is called "two overs", which is very harmful to the battery life.

2. The "two overs" and "two unders" charging stages have "two overs" and "two unders".

(1) "Two overs": one is overcharging; one is that the lead-acid battery is stored for too long and not used, and the power is not replenished regularly.

(2) "Two unders": one is undercharging of the lead-acid battery. The battery is often not fully charged, and the plate cannot be restored in time after sulfurization, which is extremely taboo for lead-acid batteries; the other is the lack of balance between the individual cells in the battery pack, resulting in a larger and larger gap between the discharge and charge levels of the individual cells in a group of batteries, and the undercharged ones become more undercharged, and the over-discharged ones become more over-discharged. This affects the life of the entire battery pack and increases your own economic expenses.

"Two overs" and "two unders" are the biggest enemies of batteries and should not be underestimated. However, "two overs" and "two unders" are caused by people themselves, and the problem is also complicated. There are many reasons, from the selection, use and maintenance, the rationality of the matching of controllers and chargers, and the timely detection of battery failure causes, etc. They are interrelated.

The reasons why the battery heats up when charging are:

During the charging process, part of the electrical energy is converted into chemical energy, and part is converted into heat and other energy. It is normal for the rechargeable battery to heat up, but when the temperature is high, you should check whether the charging current is too large or there is a short circuit inside the battery.

The heat generation has little to do with the amount of electrolyte. If the amount of electrolyte in a sealed battery is small, the internal resistance will increase, which will also cause the battery to heat up and the terminal voltage to be very high during charging. Battery aging, electrolyte drying, internal short circuits, etc. can also cause heating. The charger cannot maintain constant voltage in the later stage of charging, which will cause the battery voltage to exceed the allowable value, the temperature will rise, and in severe cases, it will swell and end its life.

During use, try not to place it horizontally or upside down to prevent a large amount of gas from being produced inside the battery and not being discharged smoothly from the vent valve, especially when charging, otherwise it may cause the shell to burst.

The reasons are as follows:

a. Overcharge

    ① The floating charge current of the charger is too large and there is no timing function

    ② The charging voltage is too high after the charger parameters drift

b. The ambient temperature is too high

c. Single cell short circuit

d. The acid density is too high

e. The error of adding acid to a single cell of the battery is too large

f. The acid absorption and quantitative deviation of the partition are too large

g. The oxidation degree of the plates is different

h. The opening and closing valve pressure of the safety valve is inconsistent

i. The grouping is not strict

j. The shell is broken

k. The user privately arranges the battery into groups

In summary, various reasons cause serious water loss, resulting in thermal runaway, causing the battery to bulge and deform.

The reasons for battery discharge and heating are:

(1) Causes of discharge and heating: Discharge too quickly, it may be that the battery capacity is small, and the discharge current exceeds 0.5C for a long time. Here we emphasize: after a short-distance trip, although the battery consumes a certain amount of electricity, after it stops, the battery has a recovery process, and the electrochemical process of the plate continues, so the voltage will rise, but it does not mean that the capacity has risen; on the contrary, when the long-distance trip does not stop on the road, the electrochemical action of the plate and the consumption of electric energy are carried out at the same time, which will cause three situations:

① When the rated voltage of the motor is low, the battery capacity is small, and the working current is too large, the voltage will drop sharply and the capacity will be quickly consumed, which is most unfavorable to the battery.

② The electrochemical reaction speed of the battery can only maintain driving, and the battery has no chance to recover and breathe. If you often do full cycle charging and discharging, it will be over-consumed if you are not careful. When encountering a windy uphill, the power consumption is very large, forcing the battery plate to react sharply, and the heat of the battery shell is high, which will damage the battery and shorten its life, indicating that the capacity is not sufficient.

③ Ideally, the electrochemical reaction speed of the battery can supply enough electrical energy. The battery shell is not abnormally hot, indicating that the battery capacity is sufficient.

It should be noted that if the battery shell is obviously hot, the internal battery itself will be even hotter.