Taking The Lead

In our second instalment on the benefits of modern battery technology, Andy Burns looks at the details of installing LiFePO4s on narrowboats

The previous article discussed the benefits of fitting LiFePO4s to canal boats. This article looks in more detail at one method of installing them on a narrowboat. Who is this article aimed at? Anyone who uses a battery monitor to manage their Lead Acids (LAs) using Volts, Amps and Ahrs should have the experience to understand the requirements of LiFePO4s and the only new skill I had to learn was how to crimp fittings on 50mm battery cable. A limited ability to solder is also required! The system I have installed is relatively simple, with all modules available on the internet.

At the time of writing there are five people active on the Canal World Discussion Forum who have installed LiFePO4s, all with different DIY management systems. Each system has its own advantages. The system I installed, however, was to reflect my requirements and my type of power usage as a liveaboard, 150Ahr usage per day. Before diving into the detail, it is important to forget all you know about LAs. LiFePO4s are very different and different rules apply. My system was set up with the following requirements:

• To have a LiFePO4 system that is safe where all risks can be mitigated and managed

• Operate with my existing charge sources ie alternator (standard Beta 43 issue!) and my solar MPPT

• Retain one or more of my original LAs in parallel with the LiFePO4s to allow rapid disconnection of charge sources.

• Never allow voltage to be above 13.5V when batteries reach 100 percent State of Charge (SoC)

• Avoid voltage dropping below 12.7V to avoid a load on the retained LA battery.

• Never allow charging of LiFePO4 bank below 0°C or above 35°C

• Keep the installation simple, be reversible and not be without power during the installation.