Latest from the Blog

Planté Battery Values – On float cell voltages, ohmic measurements & specific gravities.

Friday, 8th June 2018 Technical

Although VRLA batteries have dominated the Industrial Battery Market since they became commercially available in the mid 1980’s the lead-acid Planté battery still has an important part to play. It has been argued that the Planté battery is the most reliable emergency power supply available. Whether this is true or not is a matter of opinion. What is true, is that there are many Planté batteries still in service that were installed over 20 years ago and some are still in reliable operation over 30 years of age. Planté batteries are still manufactured by a small number of companies and remain popular in many industries where reliability is paramount.

Because the voltage of VRLA batteries is not as stable as Planté batteries and specific gravity measurements cannot be taken, instruments that measure the ohmic resistance of batteries has gained popularity in trying to determine their condition. Ohmic measuring instruments were first introduced for use on VRLA monoblocs of 6V and 12V up to about 400Ah and not for 2V 1000Ah Planté batteries where the accuracy is debatable. The accuracy of these instruments remains the subject of much discussion even for VRLA batteries. In some respects it is unfortunate that these ohmic measuring instruments are sometimes used to determine the state of health of Planté batteries because they were not designed to work on large capacity cells. There is little doubt that some readers of this article will disagree arguing that they have an instrument that will work on any battery including vented NiCd. This argument is not the subject of this article but is intended to give a more practical understanding of measurements that can be readily taken with a high degree of reliability on Planté cells.

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How Much Heat Does A Lead Acid Battery Generate?

Wednesday, 10th January 2018 Technical

Occasionally we are asked very interesting questions. Recently we were asked how much heat an industrial standby battery generates. It is fair to say, it depends on whom you ask. Different battery manufacturers have different answers to this question and the different method of calculation gives significantly different answers.

The heat emitted or generated is sometimes referred to as “heat loss”.

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Comparing VRLA Battery Specification Standards.

Tuesday, 25th July 2017 Technical

The document is intended to give the reader a better understanding of the difference between the major classifications of BS 6290 Part 4 (Lead-acid stationary cells and batteries – Part 4 Specification for classifying valve regulated types) and IEC 60896 – 22 (Stationary lead-acid batteries – Part 22: Valve regulated types – Requirements).

This document is not intended to comment on the specification classifications or make any judgement to the validity of tests or claims by manufacturers. The article is intended to draw attention to the different classifications and how the British Standard varies with the latest International Standard.

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Lead Acid Batteries For Cycling Applications.

Friday, 31st March 2017 Technical

There have been many myths about lead-acid battery cycling.

This article will give the reader a better understanding of the more important aspects of battery cycling and battery choice. Different applications are discussed along with charger requirements and how the number of cycles varies with the depth of discharge. This article looks at applications where the recharge is not regular such as solar and wind charging. Intermittent diesel charging is also discussed.

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Battery Internal Resistance & Short Circuit Current.

Friday, 16th December 2016 Technical

Battery internal resistance and short circuit current values are available from battery manufacturers. The method used to arrive at the published values varies but when a method recognised by International Standards is used a comparison between products can be considered.

Searching the internet will reveal many papers discussing actual case studies where a battery has been shorted and interesting results have been obtained. With no fuse or battery circuit breaker in the system short circuits may result in fires and catastrophic failure. Alternatively, the protection may work and isolate the battery from the point of failure and the load resulting in loss of power to the equipment which the battery was intended to protect. It therefore follows that the subject of battery short circuit current can have at least two points of view when looked at in practical terms.

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How To Make A VRLA Battery.

Thursday, 27th October 2016 Technical

This article discusses the manufacturing principals and processes in the manufacture of VRLA batteries. The article discusses the manufacturing processes and how deviations from the ideal can seriously affect the finished product.

The article assumes the reader has a reasonable knowledge of the construction of both AGM and GEL types. The process described here is very much simplified but will give the reader an understanding of the processes involved in manufacturing VRLA batteries.

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