Gibbs Guide to Lead Acid (Pb) Batteries

Lead Acid Batteries (including gell-cells)

Whether you prefer electric or i.c. (gas) powered models, you’ll almost certainly be using some form of lead acid battery. Unfortunately, the vast majority of lead acid batteries die prematurely because they are not maintained properly. Replacing the battery costs time, effort and money. This guide provides all the information required to ensure your lead acid batteries achieve a long and happy life.

The Gibbs Guide to Lead Acid batteries is a comprehensive resource written specifically for modellers needing to know how to get the best from their lead acid batteries and extend their useful life. It contains a wealth of guidance and essential information along with many clearly drawn diagrams, tables and charts. Topics covered include charging, discharging, safety, de-sulphating, hints and tips, advice on choosing and buying a battery and much more.

Like all Gibbs Guides, it’s written and illustrated in a clear and easy to understand way. No assumed prior knowledge is made. Each chapter builds on the material from previous chapters, yet is also a clear explanation in its own right. By the final chapter, you'll have been presented with a concise yet very thorough guide to your lead acid batteries.

The guide applies to all types of lead acid batteries, and focuses in particular on the two most common types in modelling usage; the 12V, 7Ah SLA (sealed lead acid, or ‘gel-cell’) battery used in i.c. flight boxes, and the larger 12V car and 12V leisure batteries often used to supply field chargers for electric flight. A useful bonus is that the guide’s content also applies to any other lead acid batteries you may have in your household such as those in cars, caravans, and small appliances such as torches or camping lanterns.

This guide really can help to greatly extend the life of your batteries, and with lead acid batteries in such widespread use, investing in a copy could easily save you much more than its modest purchase price! It’s an essential reference for any modeller using lead acid batteries and/or ‘gell cells’.

Summary of contents:
Chapter 1: Battery basics
Chapter 2: Connecting cells
Chapter 3: Battery characteristics
Chapter 4: Introduction to lead acid batteries
Chapter 5: Voltage characteristics of lead acid batteries
Chapter 6: Safety matters
Chapter 7: Charging lead acid cells
Chapter 8: Lead acid cells under discharge
Chapter 9: Lead acid battery checking and testing
Chapter 10: Battery maintenance
Chapter 11: Sulphated batteries
Appendix 1: Discharge time reckoner
Appendix 2: Quick reference voltage table
Appendix 3: Top tips for lead acid batteries
Appendix 4: Two useful graphs

Chapter contents and descriptions:

Chapter 1: Battery basics
This chapter outlines basic principles applicable to all battery types. It also introduces some of the most useful basic principles of electricity, clearly explaining relevant battery-related terms such as voltage, current, resistance and the ‘C’ concept.

Chapter 2: Connecting cells
Individual lead acid cells are almost always connected together to create multi-cell batteries. This chapter explains how cells may be connected together in series and/or in parallel.

Chapter 3: Battery characteristics
This chapter expands on some basic battery principles. It explains how cell voltage varies depending on a cell’s state of charge and whether it is being charged or discharged. The effect of different loads on a battery is discussed, and the concepts of internal resistance and related heating are introduced.

Chapter 4: Introduction to Lead Acid batteries
This chapter builds on the information of previous chapters, and clearly explains the specific characteristics of lead acid batteries. A useful comparison table is included, showing how car batteries, leisure batteries and SLA types (‘gel-cells’) compare.

Chapter 5: Voltage characteristics of Lead Acid batteries
This chapter discusses how lead acid battery voltage varies depending on the conditions the battery is finds itself in. A simple graph is included showing the discharge characteristics of a lead acid battery, and how the useful capacity will vary depending on how quickly the battery is discharged.

Chapter 6: Safety matters
Charging lead acid batteries results in the production of explosive combination of oxygen and hydrogen gases. This chapter discusses how to minimise the risks of this problem. Also covered are a variety of safety precautions and a discussion of short circuits, charge leads and more. A disturbing photo of an exploded lead acid car battery is also included!

Chapter 7: Charging Lead Acid cells
This chapter discusses the ideal 3-part charge process used for lead acid batteries, which comprises bulk, float and absorption phases. Also covered are the use of chargers (including simple chargers), charge rates, minimising charge time, gassing, when to stop charging, temperature rise during charging, overcharging and more.

Chapter 8: Lead Acid cells under discharge
This chapter discusses discharge rates and the effects on recovered battery capacity, over-discharging, cycle life, self discharge, sulphating, use of batteries as a power source, storing lead acid batteries and the effect of temperature on recovered capacity.

Chapter 9: Lead Acid battery checking and testing
This chapter introduces a simple system of graphs unique to Gibbs Guides making it really easy to assess the state of charge of a Lead Acid battery with nothing more than the guide and a simple voltmeter. An alternative method of measuring electrolyte density using an easily available hydrometer is also discussed. Electrolyte density is discussed, plus a simple method of testing to find battery capacity is presented, plus a variety of other battery checking and testing issues.

Chapter 10: Battery maintenance
A short but useful chapter, this one discusses techniques which will help you extend the life of your batteries. Subjects covered include the importance of maintaining the battery in a high state of charge, electrolyte levels, keeping batteries clean, and why cell balancing is not needed.

Chapter 11: Sulphated batteries
Lead acid batteries are prone to becoming sulphated if they are not kept charged, and this is the main cause of them requiring replacement. This chapter discusses how to identify the condition, and gives comprehensive guidance about how to treat sulphation.

Appendix 1: Discharge time reckoner
This handy table makes it easy to predict the running time available from a variety of battery sizes and current combinations. It’s particularly useful for when lead acid batteries are used as a charger power source and for scale model boats which employ ‘gel-cells’.

Appendix 2: Quick reference voltage table
This table has a variety of uses. For example, after measuring your battery voltage you can use the table to quickly determine its approximate state of charge, check on your charger’s operation and so. The information will also help you to appreciate the fairly narrow voltage range over which lead acid batteries work. Values are given for 2V, 6V and 12V batteries.

Appendix 3: Two useful graphs
Presented here are a pair of graphs intended to be used together. Between them, they allow you to quickly and easily find the state of charge of a lead acid battery and decide how long to charge it for.

Appendix 4: Top Tips: a summary of best practice
A feature of every Gibbs Guide is a useful Top Tips section, which is a compact summary of the guide’s main points. The Top Tips section means you don’t have to re-read the whole guide to be reminded best practice for the use of lead acid batteries.

The choice is yours
The Gibbs Guide to Lead Acid Batteries is available either as an e-book or in the familiar paper version. Both guides contain exactly the same information and whichever you choose you’ll find the information easy to read and digest.

e-book
The e-book is simply an electronic book that you can download directly to your computer. If you choose the e-book version of this guide, you can be enjoying learning from it in just a few minutes from now – there’s no waiting for the post to arrive! The main benefits of an e-book are:

a) You’ll be able to access the information instantly
b) With no printing and shipping costs, Gibbs Guides is able to pass on a saving to you – so the e-book’s a bit cheaper than the paper version.
c) You can print a copy for your own use.

When you order the e-book, you’ll be sent a link allowing you to immediately download the document. It’s as simple as that!

Paper version
Containing the same 16,500 words of text and illustrations as in the e-book, this 44 page paper version of the guide comes in the traditional Gibbs Guides format, a compact yet comprehensive A5 booklet.

“At last I now understand why I keep having to replace my flight box battery. Now I know how to look after if properly I’m confident the new one will last for years”
PW, Scotland

“A marvellous guide. Thanks a lot”
GT, Hertfordshire

Postage and Packaging per guide

• UK - £0.95
• EU - £1.50
• Rest of World - £1.75

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