Celltech Battery Sales & Service

UPS Batteries

Services Offered by Celltech

  • UPS Batteries
  • UPS battery maintenance
  • Battery Racks/ cabinets
  • UPS battery system sizing

In order for us to provide you with a UPS battery sizing we will need the following information:

  • System load
  • Systems voltage (Input and output)
  • Autonomy (length of runtime needed)
  • Number of batteries in the string and the number of strings
  • System efficiency
  • Growth (Factoring in additional future loading/ autonomy)

UPS Battery Facts

Although most VRLA batteries may be labelled as maintenance free, this can be a bit misleading. For the longevity of the batteries, they should be checked regularly and kept within the temperature ranges for their design (typically 20° or 25°C). The charge voltages should be checked as well as the torque settings on all connectors.

It is important not to mix and match brands and age of batteries within a UPS system. If you replace 1 or 2 batteries in a string of batteries, the older batteries will age the new blocks in a short space of time, until they are in the same state as the original batteries.

All batteries, regardless of their chemistry, naturally lose their charge over time (this is called self-discharge)

Temperature effects on VRLA batteries

Typically the rating for VRLA batteries is based on an ambient temperature of 20 or 25°C. For every 8°C above ambient during use, the life of the battery will be reduced by 50%. Ideally batteries should be operated at 25°C or less. 

Battery Storage

In addition to operation, storage of batteries waiting for use is also affected by temperature. If lead acid batteries are stored at elevated temperatures (particularly in a discharged condition), they will effectively become useless. If storing batteries, they should be in charged and stored at 25°C or less. Batteries will self discharge over time and need to be recharged periodically.

Please call us on +44 (0)1744 731555 or email us for a quote or further details.

Emergency Lighting Batteries

Celltech Battery Sales & Service can provide you with all your emergency lighting battery needs, from High temp Nicad D, C and sub C batteries to VRLA and Plante batteries for central battery systems.

BS5266 1 2011

BS5266 1 2011 states the following regarding VRLA emergency lighting batteries

Batteries should be able to operate when required.

NOTE 1 It is important that batteries are correctly used, and at the end of life replaced with an equivalent and compatible battery type, to ensure that the performance of the emergency lighting is not affected.

Central power supply systems (CPS systems) that supply the required emergency power to essential safety equipment without any restriction in power output should use batteries of a type having declared life expectancy of at least 10 years at 20°C ambient temperature.

A central low power supply system (LPS system) with a limitation of the power output of the system at 500 W for 3 h or 1500 W for 1 h duration should use batteries of a type having declared life expectancy of at least 5 years at 20°C ambient temperature.

Self-contained luminaires should use batteries of a type having declared life expectancy of at least 4 years when operated in the luminaire.

NOTE 2 Batteries for central power supply systems are specified in BS EN 50171:2001. Batteries for self-contained systems are specified in BS EN 60598-2-22:1998+A2.

This applies to any systems installed from 2011.

The legislative impact within England and Wales, has meant there has been a rising amount of non compliance cases since 2007, resulting in 6 jail terms being dealt in 2011, with fines exceeding £1.4M

Commercial, automotive, leisure and traction batteries should never be used in Emergency Lighting applications

Hi Temp Nicad D, C and sub C cells

Cyclindrical Nickel Cadmium batteries are the ideal power choice for emergency lighting and portable power applications. This reliable power source will provide high capacity power with long service life.


  • High Capacity - Using latest technology, Yuasa Nicad product has some of the highest capacities available.
  • Long Service Life - Depending upon application up to 1000 charge / discharge cycles can be expected.
  • High Temperature Options - Some popular cell sizes are available in high temperature versions.
Emergency battery types

Please call us on +44 (0)1744 731555 or email us for a quote or further details.

Fire & Security Batteries

Fire Alarm Control Panel Power Units

Two power supplies are required i.e. mains and battery and these are normally built into the Fire Alarm Control Panel. Standby batteries must allow the system to operate without mains for 24 hours longer than the building is likely to be unoccupied and then support the sounders for an additional half hour. If the mains supply is supported by an emergency generator then six hours standby plus half an hour alarm load is sufficient. All modern Fire Alarm Systems are 24 volts.

On the medium and larger sized Fire Alarm Systems, the standby batteries will often not fit within the Control Panel. Where standby batteries are contained within a separate housing, then this housing must be as close as possible to the main Fire Alarm Control Panel. If the power supply or battery housing is located more than 10 metres from the main Fire Alarm Control Panel then serious volt drop problems can arise. Standby batteries are invariably of the VRLA variety. Use of Nickel Cadmium Batteries is not cost effective and automotive batteries must not be fitted.

Points to consider:

  • System voltage
  • Battery charger output
  • Battery capacity
  • Indication of battery and/or mains supply failure
  • Secondary battery exclusive to fire protection system
  • Where system voltage exceeds extra-low voltage compliance

Choosing the correct batteries for your system

Choosing the proper system batteries requires a bit of simple math. If the system is 12VDC-based, then include two 12V batteries in parallel and add up the combined battery ampere-hour (Ah) rating. For example, two 12V-7Ah batteries will provide 12VDC-14Ahs of backup. If the system is 24VDC-based, then include two 12V batteries in series (to equal 24VDC), but do not add the combined ampere-hour rating. Two 12V-7Ah batteries will provide 24VDC-7Ahs of backup.

Because your standard alarm systems will usually require more than 7Ahs of backup current, there are also batteries available with significantly higher capacities to cater for longer battery autonomies. Keep in mind that if you wander into those numbers, properly sized enclosures will be required. Even more importantly, you will need to verify that the power supply for your alarm system can handle a charging load of that magnitude. You may need to add an external power supply to meet the demand.

Please call us on +44 (0)1744 731555 or email us for a quote or further details.

Telecom Batteries

Designed for telecom applications; excellent as “floor space savers” for marine and vehicle applications

The deep cycle AGM telecom series has been designed for use in telecom systems. With front access terminals and small footprint, the batteries are ideal for racked systems (typically 19"). Similarly, these batteries can help solve limited floor space

AGM technology

AGM stands for Absorbent Glass Mat. In these batteries the electrolyte is absorbed into a glass-fibre mat between the plates by capillary action.

Low self-discharge

Because of the use of lead calcium grids and high purity materials, VRLA batteries can be stored during long periods of time without recharge. The rate of self-discharge is less than 2% per month at 20°C. The self discharge doubles for every increase in temperature with 10°C.

Low internal resistance

Accepts very high charge and discharge rates

High cyclic life capability

More than 500 cycles at 50% depth of discharge

Please call us on +44 (0)1744 731555 or email us for a quote or further details.

Solar Batteries

Renewable Batteries

In stand-alone systems, the power generated by the solar panels is usually used to charge a lead-acid battery. Other types of battery such as nickel-cadmium batteries may be used, but the advantages of the lead-acid battery ensure that it is still the most popular choice. A battery is composed of individual cells; each cell in a lead-acid battery produces a voltage of about 2 Volts DC, so a 12 Volt battery needs 6 cells. The capacity of a battery is measured in Ampere-hours or Amp-hours (Ah).

Battery Types

The number of times a battery can be discharged is known as its cycle life, and this is what determines its suitability for use with solar cells. Car batteries are the most common type of lead-acid battery, but will survive only 5 or 10 cycles so are unsuitable for our purposes. For solar applications a battery needs to be capable of being discharged hundreds or even thousands of times. This type of battery is known as a deep-cycle battery, and some of the many different types are explained here.

Leisure Batteries

Leisure batteries or caravan batteries are usually the cheapest type of deep-cycle battery. They look similar to a car battery but have a different plate construction. Their capacity is normally in the range of 60 to 120 Ah at 12 Volts, making them most suitable for smaller systems. The cycle life of leisure batteries is limited to a few hundred cycles, meaning that they are most suitable for systems which will not be used every day, such as those in caravans or holiday homes.

Traction Batteries

The term traction battery relates to batteries used to power electric vehicles. This can mean anything from a mobility scooter to a fork-lift truck, so encompasses capacities ranging from 30 Ah to many hundreds. The smaller traction batteries are usually 6 or 12 Volt blocks, and the larger capacities tend to be single 2 Volt cells. Traction batteries are ideal for solar power applications, as they are intended to be fully discharged and recharged daily. The larger traction batteries can withstand thousands of discharge cycles. There are also batteries known as semi-traction batteries, which can be thought of as higher quality leisure batteries, exhibiting a greater cycle life. Marine batteries also fall into this category.

VRLA Batteries

VRLA batteries, ranging from 0.8ah stand-by batteries through to single cells of thousands of Ah. The advantages of VRLA batteries are obvious; they need little maintenance and are sealed allowing for operation in any orientation. They do have disadvantages however; they are more expensive than other battery types, they require more accurate charging control and can have a shorter life, especially at high temperatures. VRLA batteries are most appropriate where the solar power system will need to operate for long periods with little maintenance.

Please call us on +44 (0)1744 731555 or email us for a quote or further details.