Cleaning batteries
A clean battery is essential, not only for the sake of appearance but also to avoid accidents and damage to property as well to prevent a reduction in
service life and battery availability.
Batteries and trays must be cleaned in order to ensure that the cells have the required insulation from each other and from earth and from external con-
ductive parts. Furthermore, cleaning prevents damage caused by corrosion and leakage currents.
Under DIN EN 50272-3, the insulation resistance of traction batteries must be at least 50 Ω per volt of nominal voltage. In accordance with
DIN EN 1175-1, the insulation resistance of batteries for electric forklift trucks may not be less than 1,000 Ω.
The battery is a piece of electrical equipment with external connections protected against accidental contact by means of an insulating covering.
However, because of the presence of voltage between the terminals and the connections led out through a non-conducting plastic cover, this cannot be
equated with electric insulation.
It is not possible to prevent dust depositing on the battery, whereby the extent depends on the site of installation and length of use. During battery char-
ging, small quantities of electrolyte particles above the gassing voltage escape and form a layer on the cells or the battery block covers which is more
or less weakly conductive. Leakage current flows through this layer then, leading to increased and varying self-discharging. This is one of the reasons
why drivers of electrical vehicles complain about inadequate capacity after a weekend of the battery being idle.
Where leakage currents are higher, it is not possible to rule out electrical sparks, which can cause the charging gas (oxyhydrogen gas) coming from the
cell plugs or cell valves to explode.
This means that cleaning the batteries not only ensures high availability but it is also an essential factor in compliance with accident prevention regulati-
ons.
Cleaning vehicle traction batteries
• The danger warnings in the operating instructions for vehicle traction batteries must be observed.
• Before cleaning the battery, remove it from the vehicle.
• The site for setting up the battery for cleaning must be chosen to ensure that rinsing water, which contains electrolytes, is passed on to a suitable
waste water treatment unit. When disposing of the used electrolytes or rinsing water, observe the industrial safety and accident prevention
regulations as well as the regulations relating to the use of water and treatment of waste.
• Safety goggles and protective clothing must be worn.
• The cell plugs may not be removed or opened but must keep the cells closed.
Follow the manufacturer's cleaning directives.
• The plastic parts of the battery, in particular the cell boxes, may only be cleaned with water and/or water-soaked cleaned rags without additives.
• After cleaning, the battery surface must be dried by suitable means, e.g. with compressed air or cleaning cloths.
• If liquid gets into the battery tray, it must be extracted by suction and disposed of in compliance with the above rules
(for the relevant details see draft DIN EN 50272-3, or the ZVEI leaflet „Vorsichtsmaßnahmen beim Umgang mit
Elektrolyt für Bleiakkumulatoren" [„precautionary measures when dealing with electrolytes for lead-acid storage batteries"]).
Vehicle traction batteries can also be cleaned with high-pressure cleaning equipment. Here, the directions for use of the high-pressure cleaning units
must be followed also.
The following points must be observed in order to avoid damage to the plastic parts, such as the cell connectors, cell connector insulation and the
plugs:
• The cell connectors must be tightened securely or pushed in firmly.
• The cell plugs must be put on, i.e. closed.
• No cleaning additives may be used.
• The maximum permissible temperature setting for the cleaning device is: 140° C. This usually ensures that the temperature at a distance of 30 cm
behind the outlet nozzle does not exceed 60° C.
• There should be at least 30 cm space between the jet cleaner's outlet nozzle and the battery's surface.
• The maximum operating pressure should be 50 bars.
• To avoid local overheating, the jet cleaner should spray over a large surface on the batteries.
• Do not expose any point to the jet spray for longer than 3 seconds at a time.
• After cleaning, the battery surface must be dried by suitable means, e.g. with compressed air or cleaning cloths.
• No hot air devices with open flame or glow wires may be employed.
• The battery surface temperature may not exceed a maximum of 60° C.
• If liquid gets into the battery tray, it must be extracted by suction and disposed of in compliance with the above rules
(for the relevant details see draft DIN EN 50272-1, or the ZVEI leaflet „Vorsichtsmaßnahmen beim Umgang mit
Elektrolyt für Bleiakkumulatoren" [precautionary measures when dealing with electrolytes for lead-acid storage batteries]).
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