Technical information

Some people hate long explanations. Here are the bare facts about split charging and batteries.
Specific Gravity and State of Charge.
Fusing of our products.
The Charge Efficiency anomoly - why "Charge Efficiency" is so useless.
A "peukert type effect" during charging?
Assisted Battery Venting using SmartBank.
Let's rethink the entire split charging and monitoring system.
Interconnecting multple batteries to form one bank.
What is "surface charge"? (and "surface discharge" and "battery recovery")
Should the electrical systems be bonded to the hull?
Increasing alternator charge voltages - the cheap way.
Adding a float voltage once the alternator voltage has been increased.
Selecting the right size and type of cable.
Narrowboat AC systems.
Evolving the perfect DC system.
Wiring up an isolation transformer.
Galvanic Isolator or Isolation Transformer?
Peukert maths in depth
A quick plug that acknowledges our expertise.
RMS Voltage. What it means and why it is so important to use the correct type of meter.
Watts, VA, Power Factor. What does it all mean and how relevant is it?


Specific Gravity and State of Charge are intimately related. However the relationship is not an obvious one except to experienced user of lead acid batteries. This document attempts to explain the relationship and in the process also, out of necessity, explains the operation of lead acid batteries, the ageing process of batteries and serveral other phenomena. The document is highly technical.

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Fusing of our products is very simple. This document details required fuse sizes and the reasoning behind it.

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The Charge Efficiency anomoly. Charge efficiency is basically the amount of power got out of a battery (during discharging) as a fraction of the amount of power put into the battery (during charging). It is usually expressed as a percentage. Until one tries to actually use this figure it does not usually become clear just how misleading it actually is. This document explains the reasons why "charge efficiency" is really nothing more than a useless number.

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Peukert and Charging? Having got this far, hopefully you will now understand all about Peukert's effect and how it affects the available power that can be "got" from a battery. Here we attempt to explain what causes it (as opposed to quantifying it's effects) which leads naturally to the conclusion that there is a similar (but not so easily quantifiable) effect during charging. An effect that is incalculable, cannot be used to make any predictions and is yet one more explanation of why amp hours counters simply do not work.

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It is sometimes necessary to force vent battery compartments. Chris Gibson's narrowboat, Lionheart No 2, uses such a system with automatic, dual speed, activation of the venting fans. With the installation of SmartGauge and SmartBank this can be achieved very easily and almost for free. Click here for full details and wiring diagrams.

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It's time for a rethink on the charging, split charging and battery monitoring systems that are currently being installed. These systems are tired, old fashioned and need updating. Click here for a summary of what we are trying to achieve with these systems, why existing systems do not work, why they are more expensive than better systems and how SmartGauge Electronics' revolutionary products can help drag your tired, old, inefficient system into the 21st Century.

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Interconnecting multiple batteries to form one total battery bank is something that never receives any thought or consideration. Afterall it's so simple, what could go wrong? We just link the battery positives and negatives together, then take all the feeds from any post right? Well no, not if you want your batteries to work correctly and be balanced correctly. Even if you think you know how to do this correctly, you probably don't.

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What is "Surface Charge"? Another term that gets thrown around like confetti. Have you ever asked anyone to explain it? Or to explain how it affects battery run times and recharging requirements? Click here for a very simple explanation. This also covers "surface discharge" (much less commonly heard) and "battery recovery".

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Should the electrical systems be bonded to the hull? A nightmare of a question due to the huge number of points to consider. However, when everything is considered the answer is simple... "yes they should - without exception". The subject is surrounded with folklore, misunderstanding and myths. Click here for the full reasoned explanation of why they should be bonded.

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Increasing alternator charge voltages the cheap and easy way.

If you have read this and accept it, and you have an alternator charging at a lower than ideal voltage then you may think your only options are to change the alternator or to fit an external alternator controller.

This may not be necessary. Click here to see a very simple method for increasing the charge voltage of your internally regulated alternator.

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If the above modification to increase the charge voltage has been carried out, it may be desirable to add a float charge function once this higher voltage has been reached. This will reduce the alternator charge voltage to a lower, safer, level. If a SmartGauge is installed this modification is extremely simple as detailed here.

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Selecting the right cable rests mainly on 4 points. The rules for these are very easy and there really is nothing clever or complicated about working out what the correct size and type of cable is. Click here for the simple way to ensure you use the correct cable.

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Some typical AC systems for narrowboats. AC wiring Diagrams for typical Narrowboat AC electrical systems. Nothing complex, nothing clever. Just tried and tested systems that operate reliably, are simple to install and simple to operate.

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A tour of many possible of DC systems. A sightseeing trip to enable you to see all options before deciding on how you will rewire your DC system. See the pitfalls of each method before falling into them.

Most DC systems on narrowboats seem to have grown from an initial installation. And each stage of growth often seems to make thing worse rather than better. Here we start off with a wiring diagram of the most basic system as it comes from the engine supplier with the addition of a domestic bank. The diagrams then take you through a tour of the various options for split charging, alternator options etc. The conclusion is that typical systems are far from ideal. Click here to start the tour.

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Wiring an isolation transformer is something that often causes confusion. The reasons for it's existence are clear, but there seems to be 2 schools of thought on exactly how it should be wired up, and the reasons why. Click here for our usual reasoned discussion which leads naturally to the correct conclusion.

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Previously the choice of using a Galvanic Isolator or an Isolation Transformer was a relatively simple decision. This is no longer the case. See here for the full story.

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Peukert's Equation in depth. A fully detailed, mathematical, explanation of why various different versions of Peukert's equation exist. Which is right and which is wrong? (actually they are all right, but some need to be used with caution regarding the battery capacity rating). This article starts with an explanation of the reason the basic equation of T=C/In is no use whatsoever given normal battery ratings, explains, mathematically, how and why our modified equation of T=C(C/R)n-1/In works and expands this equation to a new version which allows Peukert's exponent to be calculated from a simple battery discharge table or curve. Also includes a spreadsheet to do this calcuation for you. The maths is, out of necessity, somewhat involved but that won't stop anyone using the ready made spreadsheet.

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It's always gratifying when an article finds itself referenced by another technical document. A technical document about Battery Modelling (see reference [9]) written at Ohio State University references our explanation of "Surface Charge and discharge..

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RMS Voltage measurements and meanings are fully understood (or should be!) by every electrical and electronic engineer in the world. However the concept has led to many queries from customers for a simple layman's explanation. Here is our attempt to fulfill this request.

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A rather involved article explaining Power Factor, Apprent Power and Real Power. Click here if you really need to know the full gory details.

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Technical information


 

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Page last updated 02/04/2008.
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