title: Tracking battery state-of-charge in a continuous use off-grid electricity system

authors: Apperley, Mark

subjects: state-of-charge

abstract: The growing importance of batteries in the delivery of primary energy, for example in electric vehicles and isolated off-grid electricity systems, has added weight to the demand for simple and reliable measures of a battery's remaining stored energy at any time. Many approaches to estimating this battery state-of-charge exist, ranging from those based on a full appreciation of the chemistry and physics of the storage and delivery mechanisms used, and requiring extensive data on which to base an estimate, to the naive and simple, based only, for example, on the terminal voltage of the battery. None, however, is perfect, and able to deliver a simple percentage-full figure, as in a fuel gauge. The shortcomings are due to a range of complicating factors, including the impact of rate of charge, rate of discharge, battery aging, and temperature, to name just some of these.
This paper presents a simple yet effective method for tracking state-of-charge in an off-grid electricity system, where batteries are in continuous use, preventing static parameter measurements, and where charge/discharge cycles do not necessarily follow an orderly sequence or pattern. A reliable indication of state-of-charge is, however, highly desirable, but need be only of fuel gauge precision, say to the nearest 12-20%. The algorithm described utilises knowledge of the past, and constantly adapts parameters such as charge efficiency and total charge capacity based on this knowledge, and on the occurrence of specific identifiable events such as zero or full charge.

text: Tracking battery state-of-charge in a continuous use off-grid electricity system The growing importance of batteries in the delivery of primary energy, for example in electric vehicles and isolated off-grid electricity systems, has added weight to the demand for simple and reliable measures of a battery's remaining stored energy at any time. Many approaches to estimating this battery state-of-charge exist, ranging from those based on a full appreciation of the chemistry and physics of the storage and delivery mechanisms used, and requiring extensive data on which to base an estimate, to the naive and simple, based only, for example, on the terminal voltage of the battery. None, however, is perfect, and able to deliver a simple percentage-full figure, as in a fuel gauge. The shortcomings are due to a range of complicating factors, including the impact of rate of charge, rate of discharge, battery aging, and temperature, to name just some of these.
This paper presents a simple yet effective method for tracking state-of-charge in an off-grid electricity system, where batteries are in continuous use, preventing static parameter measurements, and where charge/discharge cycles do not necessarily follow an orderly sequence or pattern. A reliable indication of state-of-charge is, however, highly desirable, but need be only of fuel gauge precision, say to the nearest 12-20%. The algorithm described utilises knowledge of the past, and constantly adapts parameters such as charge efficiency and total charge capacity based on this knowledge, and on the occurrence of specific identifiable events such as zero or full charge.

year: 2014

title: A collaborative community education model: Developing effective school-community partnerships

authors: Eames, Chris W.

abstract: Despite school-community partnerships having much potential to provide educational organisations with authentic teaching and learning opportuni- ties through community-based action projects, they remain under-utilised largely due to the structural constraints and pressures faced by teach- ers. This study helps ll a gap in scholarly discourse about the speci c ways in which school-community partnerships can effectively be developed by providing an in-depth account of an 18-month pilot project with the aim to develop a conservation education program (Kids Greening Taupo ̄) through a partnership structure in Aotearoa New Zealand. An evaluation of the pilot project was conducted using an ethnographic approach, which sought stakeholder perspectives about the program’s developmental pro- cess through an interpretive lens. Qualitative data were collected through participant observation, semi-structured interviews and document anal- ysis, and then thematically analysed. The ndings provided in this arti- cle illuminate stakeholder insights and perspectives about the structures established and processes utilised over the three broad stages of pro- gram planning, implementation and maintenance, and the resultant envi- ronmental initiatives and programs. Through this study, a Collaborative Community Education Model has emerged that may serve as a potential framework or starting point for those interested in creating a new school- community partnership or to modify an existing one.

text: A collaborative community education model: Developing effective school-community partnerships Despite school-community partnerships having much potential to provide educational organisations with authentic teaching and learning opportuni- ties through community-based action projects, they remain under-utilised largely due to the structural constraints and pressures faced by teach- ers. This study helps ll a gap in scholarly discourse about the speci c ways in which school-community partnerships can effectively be developed by providing an in-depth account of an 18-month pilot project with the aim to develop a conservation education program (Kids Greening Taupo ̄) through a partnership structure in Aotearoa New Zealand. An evaluation of the pilot project was conducted using an ethnographic approach, which sought stakeholder perspectives about the program’s developmental pro- cess through an interpretive lens. Qualitative data were collected through participant observation, semi-structured interviews and document anal- ysis, and then thematically analysed. The ndings provided in this arti- cle illuminate stakeholder insights and perspectives about the structures established and processes utilised over the three broad stages of pro- gram planning, implementation and maintenance, and the resultant envi- ronmental initiatives and programs. Through this study, a Collaborative Community Education Model has emerged that may serve as a potential framework or starting point for those interested in creating a new school- community partnership or to modify an existing one.

year: 2018

title: Alternative anthropologies: Kete aronui from the Waikato

authors: McCormack, Fiona

abstract: As three anthropologists working at the University of Waikato in Hamilton, Aotearoa (New Zealand), we experience anthropology in our daily work in the context of our local histories, communities and politics. While many anthropologists are familiar with the critiques of anthropology that play out in the USA or Europe, the narratives and practices of anthropology from places such as New Zealand are less well known. We argue that these local, diverse experiences of anthropology can enlarge our international understandings and imaginations of what anthropology can be, as well as the challenges it may face.

Anthropologists working in New Zealand today face the same plethora of academic pressures as those found in their counterparts in North America, Britain and Europe; pressures instigated by decades of neoliberal reform, managerialism, and the impact of new entrepreneurial and corporate models of universities that shape everyday identities and social relationships (Shore 2010). Similarly, the critique of anthropology as a discipline rooted in colonial imperatives and practices, resounds in a society whose imperial history and settler colonial present continues to imprint on educational institutions, pedagogy and research. In New Zealand, no neat historical trajectory marks a path from extractive research, wherein Indigenous knowledge and ways of life are pottled for export to the empire’s core, to one based on mutuality, co-creation and the indigenisation of anthropological knowledge.

text: Alternative anthropologies: Kete aronui from the Waikato As three anthropologists working at the University of Waikato in Hamilton, Aotearoa (New Zealand), we experience anthropology in our daily work in the context of our local histories, communities and politics. While many anthropologists are familiar with the critiques of anthropology that play out in the USA or Europe, the narratives and practices of anthropology from places such as New Zealand are less well known. We argue that these local, diverse experiences of anthropology can enlarge our international understandings and imaginations of what anthropology can be, as well as the challenges it may face.

Anthropologists working in New Zealand today face the same plethora of academic pressures as those found in their counterparts in North America, Britain and Europe; pressures instigated by decades of neoliberal reform, managerialism, and the impact of new entrepreneurial and corporate models of universities that shape everyday identities and social relationships (Shore 2010). Similarly, the critique of anthropology as a discipline rooted in colonial imperatives and practices, resounds in a society whose imperial history and settler colonial present continues to imprint on educational institutions, pedagogy and research. In New Zealand, no neat historical trajectory marks a path from extractive research, wherein Indigenous knowledge and ways of life are pottled for export to the empire’s core, to one based on mutuality, co-creation and the indigenisation of anthropological knowledge.

year: 2025