Mercedes-Benz:: S-class W140:: Check and charging of the rechargeable battery

7.2.2. Check and charging of the rechargeable battery

The low-served rechargeable battery

If the annual run of the car is small, for check of state of charge of the accumulator each three months should be measured electrolyte density. Measure density by the areometer.

Keep in mind that data are provided for electrolyte temperature 15 °C. At increase in temperature by each 10 °C it is necessary to add on 0.007, at similar reduction - to read on 0.007.

If the condition of the battery causes fears, check electrolyte density in each can. The difference more than on 0.040 indicates loss of electrolyte or damage of plates.

If the difference in density exceeds 0.040, the battery is subject to replacement. If the difference in density satisfactory, but the battery is discharged, it is necessary to load and check it electrolyte density. The sequence of actions at charging is given below.

Unattended rechargeable battery

If the tight rechargeable battery is installed on the car, to check density of electrolyte and it is impossible to restore its level. The condition of the battery can be checked by means of the built-in indicator or the external voltmeter.

Some models are equipped with unattended batteries which case the indicator of degree of state of charge is built in. It is located from above and changes the color at change of degree of state of charge of the battery. If the indicator has green color, the battery is completely charged if the indicator red - the battery has to be charged. The sequence of actions when charging battery is given below in this Chapter. Batteries of other producers can have the built-in indicator of degree of state of charge too. In this case follow the instructions provided in the maintenance instruction of the rechargeable battery.

Rechargeable batteries of all types

When checking the battery by means of the external voltmeter connect it to plugs and compare the received result to the data provided in Specifications. The result of measurements will be true if the battery was not charged at least within the last 6 hours. If it was loaded - include for 30 seconds of a headlight, then wait 5 minutes and check tension on plugs. All other electric equipment (including even intra saloon lighting) at the same time has to be switched on.

If result of measurements less than 12.0 In, then the battery is discharged, and tension from 12.0 to 12.4 signals about a partial razryazhennost.

If the battery needs to be charged, remove it from the car (see the Section Check and adjustment of a corner of an advancing of ignition) and load, following the procedure described below.

Check of fastening of plugs of the rechargeable battery and holder

If the rechargeable battery is badly fixed or plugs are not fixed, then premature failure of the battery because of vibration, ignition of cables or malfunction in operation of electric equipment can turn out to be consequence.

As at not attached battery the memories given electronic blocks, for example, of the radio receiver are erased, study remarks on removal and installation of the rechargeable battery (see Chapters Routine maintenance and the Operation manual)

Move plugs of the rechargeable battery in different directions and check reliability of their fastening, if necessary tighten.

If the rechargeable battery is badly fixed, tighten a fastening bolt the moment of 20 Nanometers.

Check of the rechargeable battery under loading

PERFORMANCE ORDER

1. Attach the voltmeter to battery plugs.
2. Start the engine and check tension.
3. At engine launch at completely charged battery tension should not fall lower than 10 V (at a temperature of electrolyte about +20 °C).
4. If tension sharply falls and density of electrolyte in various sections is various, the battery is damaged and it needs to be replaced.

Charging

The sequence of actions given below can differ from recommended by the producer of the accumulator installed on the car. In this case use recommendations of the producer.

The ordinary and low-served rechargeable battery

It is necessary to charge the battery with the current equal to 10% of capacity (for example if the capacity of the battery makes 45 Ach, it is necessary to load it with current 4.5 A) until within 4 hours electrolyte density in banks does not increase.

On the other hand, the automatic charger with current about 1.5 And can be left included on all night long.

Chargers of the "accelerated" type which, allegedly, can charge completely the accumulator in a couple of hours are not recommended to be used as at big currents of a plate of the battery can overheat and collapse.

When charging battery you watch that temperature of electrolyte did not exceed 37.8 °C.

Charging of the unattended battery

The full charge of the battery of this type will require bigger time, than for charging low-served or usual. Duration of charging depends on degree of a razryazhennost and can take up to three days.

Tension developed by the charger has to lie in the range of 13.9 - 14.9 Volts, current should not exceed 25 amperes. Under existing conditions the battery can be used in 3 hours, tension on plugs has to be about 12.5 Volts. Achievement of a full charge will take longer time.

Remarks on security measures

Before charging of the rechargeable battery study remarks on the security measures given in the Section Check of a Condition of the Battery, care of it and charging).

Do not switch-off the rechargeable battery at the working engine.

Never close the battery накоротко, i.e. do not connect positive (+) and negative poles. At the same time the battery is warmed and can burst.

Do not use an open flame near the battery. Electrolyte is poisonous. Do not allow its hit in eyes, on skin and on clothes. Otherwise plentifully wash out electrolyte water.

At the battery with the central gas outlet, at a charge, do not turn out a stopper (crosswise vents).

Before charging of the frozen battery let's it thaw. The charged battery freezes at a temperature about 65 °C, the semi-charged battery at a temperature about 30 °C and discharged at a temperature about 12 °C. After thawing check the battery for existence of cracks. If necessary replace.

At a battery charge the normal charger or the device with the accelerated charging remove the battery. At least, disconnect a negative and positive cable (+).

At use of the portable charger (small current) charging can be carried out without removal of the battery. The connecting cable to onboard network is not required to be disconnected at the same time. It is necessary to consider data of the manufacturer of the battery, naturally.

Charging of strongly discharged and sulfatirovanny rechargeable battery

It is impossible to charge strongly discharged battery with the device for a bystry charge at all.

The rechargeable battery, long time which was not used (for example, at the long parking of the car), is discharged and sulfatirutsya over time.

If tension of idling of the battery lies lower than 11.6 In, then the battery is considered strongly discharged. Check rest tension, at the same time address the Section Check of a Condition of the Battery, care of it and charging).

At strongly discharged battery electrolyte consists almost of one water.

At a negative temperature such battery can freeze, and the case of the battery to burst.

Strongly discharged battery sulfatirutsya, i.e. on a surface of electrodes large slightly soluble crystals of sulphurous lead are formed. Electrolyte at the same time loses transparency and gets weak white coloring.

If strongly discharged battery is charged directly after the category, sulphation happens again. Otherwise plates of the battery continue to harden and the possibility of a charge of the battery for a long time remains limited.

Strongly discharged and sulfitirovanny battery has to be charged with the lowered current about 5%, i.e. at, for example, capacity of the battery 60 of Ach force of charging current has to make 3 A.

Tension of a charge has to make no more than 14.4 Century.

Bystry charging / help at start

Charge with the device for a bystry charge the battery only for ensuring start of the car. At the same time force of charging current makes 20% and more from battery capacity. At the same time the battery is damaged since is affected by big currents. Time not used and strongly discharged battery is long it is not necessary to load with the device for a bystry charge since it leads to sulphation.