Active substance detachment

1. The reason for the detachment of the active substance

(1) The initial charging current is too large. Because the reduction of the active material of the plate starts from the grid with the best conductivity, when the high current is charged, the lead sulfate is rapidly reduced there, so the lead sulfate far away from the grid cannot react in time, because the volume of lead sulfate is relatively large. If it is large, the adhesion with the reduced active material inside is poor, so it is easy to fall off the electrode plate.

(2) The current at the end of charging is too large. In this way, a large number of air bubbles are generated, which violently impact the surface of the electrode plate, so that the reduced relatively soft lead dioxide falls off in large quantities.

(3) Frequent overcharging. Although the overcharge current is not large, the lead sulfate on the plate has been completely reduced to lead dioxide and lead, and the charging current is all used in the electrolyte. The impact on the surface causes the active substance to fall off.

(4) The discharge current is too large, and the chemical reaction is intense at this time, which will cause the warping of the electrode plate, thereby causing the active material to fall off.

 2. Processing method

Since the active material falls off, the plate will be short-circuited, causing the battery to discharge itself. The battery must be disassembled for repair, and it is recommended to replace it.

1. Fault phenomenon

Plate sulfation is a common failure of batteries, and many battery failures also occur due to this failure. Plate sulfation is mainly manifested as: the voltage rises quickly during charging, gas is released prematurely, and the temperature rises rapidly; during discharge, the voltage drops rapidly and the capacity is small.

2. Troubleshooting and handling

The reasons for the irreversible sulfation of the plates are summarized as follows:

(1) The storage time is too long, the self-discharge rate is high, and it is not maintained and charged.

(2) It is not charged in time after discharge.

(3) Under-charged state for a long time.

(4) Over-discharge.

(5) Dried up or the electrolyte concentration added is too high.

When irreversible sulfation occurs in the battery, it should be repaired according to its severity.

Those with lighter salt can be restored to normal by performing general activation charging (ie, equalizing charging) on them. The specific method is as follows:

Constant voltage current-limiting charging: The first stage is 0.18C2A charging to 2.7V/single cell charging for 12-24 hours.

The first stage of constant current: 0.18C2A is charged to 2.4V/single cell, and the second stage: 0.05C2A is charged for 5-12 hours.

Those with heavier salinity need to be charged and discharged with "hydrotherapy" to return to normal. The specific method is: first add pure water or dilute sulfuric acid with a density of 1.05g/cm3 to the battery to a rich liquid state, then charge it with a current of 0.05-0.018C2A for about 20 hours, drain the flowing liquid, and then do a capacity test. Repeat the above operations until the battery capacity is restored.

The distance is not far - the battery pack appears "unbalanced"

1. Fault phenomenon

The balance of series-connected battery packs is a common problem, and there will always be "backward" batteries in the process of use. The reasons are various, there are production reasons, there are also reasons for raw materials and reasons for use.

2. Troubleshooting and handling

First, the battery is charged for general maintenance, and then discharged with a 2h rate current. During the discharge process, the voltage of the battery is continuously measured, and the "backward" batteries with insufficient discharge capacity are selected for treatment. First add 1.05g/cm3 of dilute sulfuric acid until you just see the flowing electrolyte, and then continue to charge for 12~15h. Be careful not to exceed the temperature of the battery over 50 degrees when charging. After charging, let stand for 0.5~4h, redo 2h rate discharge. During the discharge process, measure the value of the single-cell voltage. If the discharge time does not meet the standard or the single-cell voltage reaches 1.6V, the discharge time is greatly different from the normal single-cell battery (the difference is more than 5 minutes after three months from the factory, and six months). If the difference is more than 8 minutes, the difference is more than 10 minutes in nine months, and the difference is more than 15 minutes in thirteen months), the above charging and discharging procedures need to be repeated until the requirements are met.

If the battery capacity does not increase significantly after repeated charging and discharging cycles or is still at a low voltage of about 0V, this type of battery generally has a short circuit, or the active material is seriously detached and softened, and the serious irreversible sulfation cannot be repaired. It should be scrapped. Those who meet the requirements can continue to use the battery. Under the condition of constant voltage 15V / battery, drain the electrolyte, wipe the surface of the battery, install the cap valve, and stick the panel with PVC (or chloroform) adhesive. it is good.

Single cell short circuit

1. Fault phenomenon

The phenomenon is that the starting ability is suddenly lost; when starting, the electrolyte is sprayed out of the short-circuit cell. The reason is: after a single cell is short-circuited, the resistance of the battery increases, the voltage decreases, and a strong current cannot be supplied.

 2. Cause of failure

(1) The active substance falls off.

(2) The electrolyte used has impurities.

3. Inspection and processing

The inspection method can be used to ignite the positive and negative electrodes of each grid of a thin wire. The grid with no spark or weak spark is short grid and needs to be sent for repair.

Water replenishment of battery

(1) Preparations. Use pure water and analytically pure sulfuric acid to prepare sulfuric acid solution electrolyte, the ratio is: 500ml pure water, add 0.5ml pure sulfuric acid. Prepare a standard rubber vent valve as a spare. Tools: screwdriver, straw (can be replaced with disposable needle), transparent polyethylene tube, the diameter should be suitable for the suction mouth of the straw (needle), ABS glue.

(2) Pry off the cover above the battery along the vent hole. Some battery covers are ABS glued, and some batteries are snap-connected. Be careful not to damage the cover when prying open the cover. This is the rubber cap where the 6 exhaust valves can be seen.

(3) Open the rubber cap to expose the vent hole, through which the inside of the battery can be seen. The exhaust valve of some batteries can be unscrewed, and there are some fillers around the rubber caps of some batteries. Pay attention to the fillers.

(4) Use the dropper to inhale the configured electrolyte and inject the electrolyte through the vent hole. The electrolyte should just cover the plate by 1mm.

(5) Cover the vent hole with a cover-up cover to prevent dust from falling into the vent hole, and let it stand for 12-24 hours so that the electrolyte can fully penetrate. Observe the electrolyte inside the vent again, there should be a flowing electrolyte (free acid), otherwise the electrolyte should be replenished.

(6) Under the condition that the exhaust hole is not covered, carry out 16.2V constant voltage current limiting charging. When charging, it is best to put the battery in an acid-resistant container to prevent the spilled electrolyte from polluting the environment. When the charging current of the battery drops to 400~300 mA, or the voltage reaches 16.2V for more than three hours, the battery is considered to be fully charged for the first time.

(7) After the initial charging, check whether there is any electrolyte on the surface of the battery plate. If there is no electrolyte, the electrolyte should be replenished, and then the constant voltage current-limiting charging should be performed again; if there is electrolyte on the 6 grids, use a straw Aspirate excess electrolyte.

(8) Use 14.8V constant voltage current limiting charging until the charging current drops to 300mA.

(9) After closing the exhaust valve, pay attention to restoring the filling. Cover the battery cover, if it is glued, it should be glued. Press a heavy object on the battery cover, wait for the glue to completely solidify, and perform 4.8V constant voltage current limiting charging again until the charging current drops to 300mA.

(10) Test the battery capacity again to determine whether the battery capacity is restored.

The reasons for the unsatisfactory effect of the battery after repair (the capacity increase is not large, or the battery does not reach more than 70% of the nominal capacity) are as follows:

1. The positive plate of the battery is softened. The obvious manifestation is: in the above step (7), it will be found that there are black impurities in the excess electrolyte that is sucked out. If there are many black impurities, the positive plate is softened and discharged, such as Batteries basically cannot be repaired, they can only be scrapped.

2. The battery is vulcanized, and the battery can be repaired by electronic pulse for 24 hours after being recharged, and then tested again.

3. 30min after charging, test the battery voltage, it is still lower than 12V, it may be the internal circuit breaker of the battery, and the battery should be scrapped.