philippi Academy
Calculators and Finders of the Philippi Academy
In short
Five tools for designing an electrical system: the cable configurator for cross-section, fuse, and assembly; calculators for battery capacity and solar yield; and finders for the alternator and fuel sender. All without registration. The sequence of the installation makes sense: first the consumption balance, then the battery bank, then the charging capacity, and finally the cross-sections and fuses.
Finder
Find the right tank sensor
Liquid, tank depth, material and whether drilling is allowed determine the right sensor, including length, mounting parts and display.
Calculator
Calculate cable cross-section and fuse
Current, length and system voltage give the cross-section and matching fuse in one pass, optionally with a ready-made cable and parts list for the cart.
Calculator
Calculate battery capacity
Consumer list, days of autonomy and depth of discharge give the required nominal capacity of the battery bank.
Finder
Find the right alternator
Enter battery bank, belt system and engine power: we suggest alternator, regulator, AltMount kit and belt and get back to you by email.
Calculator
Calculate solar yield
Module power, region, season and mounting give the realistic daily yield in amp hours.
Calculation Method Instead of Black Box
Each of these calculators not only shows a result, but also how it was arrived at: formula, values used, intermediate steps. Seeing the method allows you to check the result – and notice if an input is incorrect. No registration, no data storage, traceable in both directions.
In What Order to Calculate
The calculators build upon each other, as the system does. It starts with the consumption balance – which provides the size of the battery bank. From this follows the appropriate charging current, i.e., the dimensioning of the alternator and solar. Only from currents and cable lengths do the cross-section and fuse result. Reversing this order means calculating with estimated input values.
What a Calculator Does Not Replace
All results are planning parameters, not acceptance values. They describe the cable, the battery, or the module – not the contact resistances at terminals, not the condition of an aged battery bank, and not the shading that only occurs in summer. Whether the system meets the calculated values is shown by measurements under load. The datasheets of the components used and applicable standards remain authoritative.
Michael Kögel · Managing Director, philippi elektrische systeme GmbH
Michael Kögel is Managing Director of philippi elektrische systeme GmbH in Remseck am Neckar. Since 1978, the family-owned company has developed and manufactured on-board electrical systems for yachts, motorhomes and special vehicles.
Articles in the philippi Academy are written together with the engineering department and technically reviewed. If a standard or a product specification changes, the article is revised and the review date updated.
Published · Last reviewed
Frequently asked questions. Answered briefly.
How do I find the right cable cross-section and the right fuse?
The cross-section depends on cable length, current and permissible voltage drop – the calculation uses twice the cable length, because the current flows there and back. Our cable configurator calculates cross-section and fuse automatically; you will find more calculators and tables in the philippi Academy.
Do I calculate with the single or the double cable length?
With the double. The current flows there and back, and both paths create voltage drop. A load five metres from the distribution has ten metres of conductor. This is the most common calculation error and leads to cables with half the cross-section and twice the voltage drop.
How big does my battery bank need to be?
The size follows from the daily balance and the permissible depth of discharge: with a daily requirement of 150 ampere-hours and lead batteries at 50 percent depth of discharge, you need 300 ampere-hours of nominal capacity; with lithium, correspondingly less. How to build a reliable daily balance is described step by step in Creating a consumer balance.
Advice
Rather go through it together?
Send us your values.
We check the design and usually reply on the same working day.
