Maintaining batteries
December 1st 2004

H&SS talks to Nigel Harris, export product manager at Chloride Motive Power, about how to get the most from your traction batteries

Stored energy is still the safest, most environmentally friendly and popular power source in the traction market.

Its low noise, lack of fumes and ease of maintenance make it ideal for forklifts, reach trucks, VNA trucks, power pallets, low-level order pickers and the like – particularly those operating in enclosed spaces and where hygiene is paramount (eg food and pharmaceutical applications).

However, their ease of use can make them prone to neglect.

At Handling & Storage Solutions, we posed some questions to Nigel Harris, Export Product Manager at Chloride Motive Power to get some sound advice on how to get the best from a traction battery.

Q. Are traction batteries safe? There are different types of battery, but in industry, the most common type of traction battery is the ‘flooded’ type – similar to car batteries. They are also known as lead acid batteries and as the name suggests, contain dilute sulphuric acid, which is poisonous and corrosive. It will cause burns or irritation if it comes in contact with the skin. Having said that, there are far fewer health & safety implications when compared to diesel or LPG, which are both flammable. The acid in traction batteries is contained within a very durable plastic container, which is not liable to corrosion. Incidents of injury from batteries are negligible and nearly always attributable to human negligence.

Batteries can of course be heavy and if being removed from the apparatus should only be lifted by the correct techniques or with the appropriate lifting gear.

Q. What advice would you give on handling? Generally, there are only two occasions on which a battery will need to be handled: if being ‘changed’ with another battery for charging and if being ‘topped up’. When working on batteries always wear the appropriate protective clothing and goggles.

Always handle batteries carefully and always keep them upright to avoid any spillage of electrolyte. Check bolted connections on the battery for tightness and make sure they are clean. Inspect battery and charging cable connections for wear and damage and replace where necessary. Keep the battery clean & dry to prevent electrical leakage between the cells.

When charging, the following advice should be followed; do not allow a battery to become more than 80% discharged. Keep naked flames and metal objects away from the battery and ensure that the charger and battery are properly matched in terms of recharge time, ampere hours, charge profile, and start current. If the battery is being charged in the truck, keep the truck cover open while it is being charged as batteries ‘gas’ when charging. Always try to ensure there is adequate ventilation and keep the battery ‘cool’ – preferably around 300c.

Do not overcharge the battery as this will generate heat and lead to early life failure.

Periodically, the battery will need topping up and this is perhaps the single most important aspect to any flooded battery maintenance regime.

It is vital to note however that only water should be used – never add acid.

Q. Why do batteries need topping up? The electrolyte within a battery creates a conduit between the positive and negative plates, allowing the chemical reaction to take place ie chemical energy is converted to electrical energy. During a recharge cycle, the plates within a traction battery produce oxygen and hydrogen by hydrolysis. It takes these gases from the electrolyte mixture that surrounds the plates.

Additionally, some of the water will be lost by evaporation caused by the heat that is generated.

Topping up the battery with the appropriate water ensures that the electrolyte levels are kept at an optimal state.

Q. What happens if the battery is not topped up? If the electrolyte levels are not maintained, the path for the electrons is diminished, thereby affecting the chemical reaction. Damage to the plates can also occur if they are allowed to dry out. If severely neglected, the battery could short.

Although this may be a worst-case scenario, if electrolyte levels are consistently low, the performance of the battery will be impaired and its operational life reduced, as there will be a loss of capacity in the cells.

Conversely, if a battery is overfilled, there is a risk of spillage, which is not only a health and safety issue (electrolyte is acidic) but it will result in a loss of electrolyte as well as water and will ultimately dilute the mixture.

Q. What water should be used and how should batteries be topped up safely? Tap water is not 100% pure – it contains minerals and chemicals that can damage the plates. Water needs to conform to BS4974.1975.Grade B Standard ie water suitable for lead acid batteries. Water needs to be distilled, de-mineralised or de-ionised; it can be bought pre-packaged or apparatus can be bought that will purify tap water, such as Chloride Motive Power’s ‘Aquapure’ system which de-ionises the water.

Water should be added to the battery when the level has reached the top of the plates. Many batteries will have an indicator system; for those that do not, a visual inspection is required. Carefully remove the caps and make a visual inspection of the fluid level. Be careful when doing this, especially if metal implements such as screwdrivers are being used to open the caps as there is a danger of shorting the battery and electric shock. When filling the battery, be careful of splashes as the acid can be hazardous to skin and clothes. If the fluid does come into contact with skin or clothes, immediately rinse the affected area.

Topping up should be part of a regular maintenance regime and may be required as often as every 1- 2 weeks under normal industrial usage. Using a jug is both awkward and time-consuming so at CMP Batteries we recommend the use of automatic topping up equipment like ‘Aquajet’ which is more accurate than manual filling and will pay for itself very quickly in terms of time savings. Aquajet also reduces the health and safety implications involved in leaning over the battery tray, as they can often be difficult to reach and the environment in which they are located may be poorly lit. It also makes it more difficult to fill accurately to the correct level. Another common hazard is the potential for metal objects such as belt buckles, rings and spectacles to fall onto the terminals.

Q. What are the latest technological developments in stored power? In terms of maintenance for flooded batteries, Chloride Motive Power’s ‘Aqua’ range of products are designed to save staff time on battery maintenance.

These include: • ‘Aquapure’ – water de-ionising system • ‘Aqualevel’ – a permanently connected indicator that remains illuminated as long as the correct electrolyte level is maintained • ‘Aquatrolley’ and ‘Aquagun’ – a manual filling system with a pump that works by venturi action so that the water supply is cut off when backpressure occurs.

There are also developments in batteries themselves and CMP can offer maintenance free batteries as an alternative to conventional ‘flooded’ batteries such as gel and absorbed glass matt technology that remove the need for topping up altogether.

Because of increasing global competition and rising costs, industry in the UK is looking for productivity savings to compete.

At CMP, the focus has moved from simply providing batteries to total power solutions; the more staff time that can be freed up to focus on work-related tasks as opposed to maintenance means economic advantage.

Great improvements have also been made in the battery chargers and systems.

CMP is the only UK company that actually manufactures its own chargers. This means that they are developed to meet the exact recharge specifications and requirements of the batteries.

CMP’s new multi-deck changing system is saving companies valuable floor space and improving health and safety. It is so revolutionary that it has been short-listed for the ‘Innovation’ award at the 2005 FLTA awards.

CMP.net is a computerised system that allows industry, warehouses and other users of electric vehicles to manage their batteries so they are recharged at the correct time and for the appropriate duration. This ensures optimal use of batteries, thereby extending their efficiency and life – a tangible benefit for modern businesses with 24hr operation.

Each charger is linked to a central PC that can monitor up to 255 batteries and provide real-time status reports. Charging points can be categorised by truck type or warehouse area, or any other user-defined category. The system automatically prioritises the next battery to use and alarms are triggered if an incorrect battery is removed. Security is ensured by a voltfree fire alarm interlock and automatic shutdown in the event of ventilation failure. Additionally, a ‘safety disconnect’ ensures that no power will flow if the ‘wrong’ battery is disconnected.

The integral power management facility can automatically adjust charging rates within defined power limitations by controlling the number of batteries that can be activated at any one time. User-friendly management reports can be easily extracted to show battery status, cycles charged, fault reports etc.

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