Our Household Battery Storage Part 1 by John Hermans

Abridged version of article first published in RENEW No 155

In 1981, Robyn and I moved onto our newly purchased 40 Ha bush block, and within 3 weeks had constructed a simple tin shed as our temporary bush dwelling. The energy required to run lights at night was easily provided by attaching a pair of jumper leads to our car’s battery. This means of storing energy in a Lead Acid Battery (LAB) was the start of a long history of using this technology, with each change in battery set resulting in both an increase in system size and an improvement in its technology. We only ever purchased used batteries and then did our best to stretch their usable life.

Our first set of a 12 ex Telecom, 2-volt small format, flooded cell lead acids, were sourced from a local scrap yard. Often used commercial batteries are found in reasonable condition, but private households that have scrapped their batteries are inevitably well and truly dead…

After 20 years of cost minimizing by using a variety of flooded cell LAB, (their charge-discharge cycle efficiency drops to unacceptable levels eventually), I came across a set of 12 – used 2 volt cells @ 2000AHrs at a good price. The main reason for their better price was that they weighed 250KG each! By 2015, this heavy LAB set started showing signs of low charge-discharge efficiency, so I was on the hunt for their replacement. Although I was now living in the age of Lithium, their cost was beyond our earnings ability.

As I maintained my preference for used hardware, (reuse is one-step more environmentally friendly than recycling) I did my best to acquire a set of LAB of the Absorptive Glass Mat type (AGM). I soon found an independent telco maintenance company that was prepared to sell me their swapped out 12v 100AHr AGM batteries for scrap value. This was a real win as some day when they are worn out I expect to get ‘scrap value’ back for them! On this occasion, I got 50 KW Hours of usable AGM LAB for less than $3000. (part 2 to follow)

*the author is a regular contributor to Renew and occasional contributor to this blog. He is a member of East Gippsland Climate Action Network.