A Stand Alone Power System (SPS) is made up of a number of components and none need as much attention as the batteries. As someone in the industry once put it “few batteries die a natural death, most are murdered.“ So be empowered! The following information is designed to tell you how to get the longest life possible from your battery bank made up of flooded lead acid batteries.
- design a battery bank using deep cycle batteries which allow power to be discharged slowly over a long period of time (ie do not use automotive batteries which are designed for a large amount of power to be discarged over a short period).
- allow a large enough battery bank to shallow cycle your deep cycle batteries.
- place batteries indoors in a ventilated space to maintain temperature between 18 and 25 degrees C. Keeping the batteries simultaneously warm and adequately vented can be challenging, yet with proper planning is not that difficult.
- batteries slowly lose power whether your battery bank is being used or not (self-discharge) at a rate from 1-2% per month with new batteries to significantly more as the battery ages, so some charging will be required just to stay even.
- battery connections are critical and should be clean, equally tightened and greased to prevent corrosion. Minimise the number of parallel strings in a bank.
- the main negative and positive connections on the battery bank should be made on opposing corners to keep the variation of resistance from one cell to another to a minimum.
- install a specialised DC current limited fuse and disconnect on the main battery cable, ensuring all components on the DC side of your SPS system are rated for DC use.
Smart Energy can assist with battery choice, advise on battery enclosures, provide electrical wiring diagrams and install systems safely and within required legal codes and standards.