Testing and specific gravity measurement of electric sightseeing car batteries

Battery inspection and specific gravity measurement of electric sightseeing vehicles

1. Battery inspection of electric sightseeing vehicles:

a. Visual inspection and cleaning: Check whether the battery connection is loose, whether the terminal is corroded, whether the battery box or cover is cracked or leaking. If it cannot be repaired, please replace the battery; if the terminal is corroded, the battery bracket or fixture is rusted, or the battery is very dirty, please take the time to clean it up. The cable brush can clean dust, corrosion, and rust; wipe the dust on the top of the battery with soda water, and then wipe it dry with a damp cloth. After cleaning the rust on the parts, rinse it with clean water, dry it and paint it with acid-proof paint.

b. Measure specific gravity and open circuit voltage: The amount of battery charge can be obtained by measuring specific gravity and open circuit voltage; the corresponding values of charge amount, specific gravity and open circuit voltage are shown in the following table:

2. Steps for measuring specific gravity:

a. Do not measure specific gravity immediately after adding water to the battery;

b. Use a thermometer to measure the electrolyte temperature and record the temperature value;

c. Draw electrolyte from the battery into the hydrometer, and then drain it. Repeat this 2-4 times to make the temperature in the hydrometer float consistent with the temperature of the battery electrolyte;

d. Draw enough electrolyte from a battery cell to push the hydrometer float;

e. Read and record the value, and then pour the electrolyte back into the battery cell;

f. Measure the specific gravity value of each battery cell according to the above steps;

g. Cover the cover of the vent and wipe off the dripping electrolyte;

Correction of each reading to the value at 26.7℃, the correction method is:

For every 10℃ increase in temperature, the reading increases by 0.007

For every 10℃ decrease in temperature, the reading decreases by 0.007

Check the charging status against the table above. The value read should be between 1.277±0.007. If it is lower than this value, please check and record the battery voltage, fully charge the battery and re-measure the specific gravity; if the specific gravity reading is still low, please check the battery voltage again, balance the battery and re-measure the specific gravity. If the specific gravity is still low, the following situations may occur:

a. The battery has aged and is close to the end of its service life

b. The battery has been in a discharge state for too long

c. The electrolyte has been lost due to leakage

d. There is damage to the battery cell

e. Too much water was added before measurement

If the first four situations occur, the battery should be sent to a professional for inspection or replacement.

3. Measure the open circuit voltage

To obtain an accurate open circuit voltage value, the battery must be idle for more than 6 hours

a. Disconnect the battery from other electrical appliances

b. Use a DC voltmeter to measure the voltage

c. Compare the above table to assess the charging state

d. If the data shows that the charging state is below 70%, the battery should be charged.