How long can lead acid batteries last affects millions but most written and believed about it has little basis. What people really buy are usable amp hours. What people really buy are not batteries – but usable amp hours.
The best text written about how long can lead acid batteries last is Life Time Modelling of Lead Acid Batteries. It is readable, hugely informative and tightly written. It deserves to be better known. It is truly worth reading. Some parts are very technical but much is easy to follow and understand. It is rare to find such a readable yet rigorous approach.The multiple authors are: Henrik Bindner, Tom Cronin, Per Lundsager, James F. Manwell, Utama Abdulwahid, and Ian Baring-Gould from Denmark’s Risu National Laboratory. They and Risu have generously enabled Caravan & Motorhome Books to publish the preface here.
They have also allowed the paper (in its entirety) to be down-loaded free of charge. It is at: http://orbit.dtu.dk/en/publications/lifetime-modelling-of-lead-acid-batteries(6f8d323d-dbbb-40d0-91b7-fbf74af5e017).html
‘Power system implementers commonly agree that one of the key weak links in the long-term operation of renewable based rural energy systems is the system batteries. Batteries not only impact on the system operation and performance, but also can greatly affect the life cycle cost of a specific power system. Numerous hybrid power system performance and economic models that are currently in use provide an estimate of battery life based on a number of different mathematical calculations and assumptions. These life calculations are then used to develop cost of energy estimates for the power systems.
‘Unfortunately the varying methods currently used are quite diverse with many different assumptions, and very little effort has gone into the validation of these methods. Additionally, most of the methods use calculation techniques based on information provided by manufacturers, usually under conditions that are not at all similar to the ones experienced by batteries in remote power systems.
‘Under the Benchmarking project work, two different battery life calculation methodologies have been investigated and further developed with the aim of improving the prediction of the life of batteries in hybrid power systems. One is based on a cycle counting approach similar to that used in structural fatigue analysis, the other is based on the application of a cross matrix, developed by the project for linking a number of stress factors with the recognised lead acid battery damage mechanisms.
‘Both methodologies are combined with their own battery performance model in order to link the predicted battery life time with the actual use of the battery in terms of simulated or measured charge / discharge patterns.
‘The project combines the model development with experimental verification, using both specific lab tests of selected batteries as well as field test results collected in the project’s systems test database. The reliable prediction of battery life in a given system is a precondition for providing a proper decision basis for system costs & performance, and the validation procedure established by the project is an essential part of this. The paper describes the first results of the battery model development effort as well as results from the initial model validation using standard battery performance testing for operating profiles considered representative of wind and PV powered remote power systems.’
Care is essential
As can be seen from the full paper, it is vital that your solar, cabin, camper trailer, caravan or motor home’s batteries and battery charging system is competently designed and installed. Essential also is to choose carefully when buying electrical equipment. Choosing the wrong products can be costly, only partially work, or worse – leave you stranded.
Make sure you have all the information you need by purchasing Caravan & Motorhome Electrics, Solar that Really Works! or Solar Success. The books explain in plain English all that you need to know about the complexities and choice of batteries, and related electrics. My other books are the all-new Caravan & Motorhome Book, and the Camper Trailer Book.
These books have helped tens of thousands worldwide to make the right decisions. Any one will save you many times its cost. For information about Collyn Rivers please Click on Bio.