7.2.8. Rechargeable battery

The unattended rechargeable battery, as appears from the name, does not demand service and has no ventilating traffic jams of cans of the battery.
There is no need to add water to electrolyte of the unattended rechargeable battery.

Fig. 7.47. The Vetilyatsionny opening in a cover of the rechargeable battery

The rechargeable battery is completely tight, except for a small air vent in a cover (fig. 7.47).

Fig. 7.48. Scheme of visual check of the rechargeable battery

Check of density of electrolyte

Fig. 7.49. Check of density of electrolyte

Density of electrolyte of the rechargeable battery changes with a temperature. Heating dilutes solution and reduces electrolyte density. Cooling zagushchat solution and increases density of electrolyte (fig. 7.49).
At completely charged battery density of electrolyte has to be equal to 1,260-1,280 g/cm3 at a temperature of 26,7 °C. At a deviation of the actual temperature of electrolyte from standard size it is necessary to enter the amendment: to value of density it is necessary to add 4 points (0,004 g/cm3) on each 5,56 °C of temperature over the size of 26,7 °C or to subtract 4 points (0,004 g/cm3) on each 5,56 °C of temperature less than the size of 26,7 °C.
For example: the areometer shows value of density of 1,280 g/cm3 and the thermometer shows temperature of electrolyte of-12,2 °C (10 °F). According to the provided drawing, the measured value of density has to be reduced by 7 points (0,028 g/cm3). Thus, the given value of density of electrolyte at 26,7 °C will be 1,252 g/cm3.
Calculation formula: 1,280–0,028=1,252.

Fig. 7.50. Charging of the rechargeable battery

It is not necessary to take measurements of density of electrolyte a hydrometer right after addition of water in electrolyte. In order that water and electrolyte mixed up and uniform density was established, or within several minutes slowly charge (current 5 A) the rechargeable battery, or leave the rechargeable battery motionless approximately for one hour (fig. 7.50).

If in any can of the rechargeable battery (one or several) density of electrolyte differs from average value on 50 points (0,05 g/cm3) or more, it is a sign of existence of internal damages. In this case the rechargeable battery should be replaced.

Fig. 7.51. Scheme of dependence of density of electrolyte on its temperature

Visual check of the rechargeable battery
Turn an ignition lock key in the provision of "OFF" and switch off all additional electric equipment.

Fig. 7.52. Detachment of wires of the rechargeable battery

Disconnect wires from plugs of the rechargeable battery (first of all disconnect a wire from the negative plug) (fig. 7.52).
Remove the rechargeable battery from the car.

Observe extra care if at the case of the rechargeable battery there are cracks or other sources of leak of electrolyte, avoid contact of electrolyte with skin. At removal of the rechargeable battery it is always necessary to put on suitable rubber gloves (do not use household gloves).

Check a condition of the pallet of the rechargeable battery for lack of the corrosion damages caused by leak of acid (electrolyte). In the presence of corrosion it is necessary to wash out the damaged places solution of pure warm water and soda. Clear the damaged places a rigid wire brush and wipe with fabric of the soda moistened in solution.
Clear top of the rechargeable battery solution.
Check the case and a cover of the rechargeable battery for lack of cracks. In the presence of cracks replace the rechargeable battery.
Clear plugs of the rechargeable battery the corresponding special cleaner.
Clear an internal surface of clamps of contacts of connecting wires of the rechargeable battery the corresponding special tool. Replace the damaged or worn-out connecting wires and the damaged clamps of contacts.
Install the rechargeable battery on the car.
Connect contacts of connecting wires to plugs of the rechargeable battery and be convinced that end faces of clamps of contacts are established aflush with end faces of plugs of the battery.
Reliably tighten a nut of a clamp of contact of a connecting wire.
After an inhaling apply a little mineral jellied lubricant on places of all connections.

At charging of the rechargeable battery under its cover flammable and explosive gas is emitted. You do not smoke and do not use an open flame about the rechargeable battery which is on charging, or it was recently loaded. Do not separate the chains which are energized near plugs of the rechargeable battery which is on charging. The spark can appear between the disconnected wires (in a rupture of a chain) and to become a cause of explosion. You hold flammable objects far away from the open rechargeable battery.