The Australian startup Redflow resumed delivering batteries to its customers this week. In late April the company suspended the delivery of batteries to customers after informing investors about a number of technical issues including electrolyte impurities that could cause system failure. This week CEO Simon Hackett informed investors in a letter that testing upon a new batch of batteries was successful and therefore deliveries could resume.

Redflow manufactures the ZCell, a miniaturized zinc-bromide flow battery for residential applications. The company makes bold claims about its batteries stating their units outperform lithium-ion batteries in almost every respect. However, as explained in a letter to investors last month Redflow faces technical challenges. Mr. Hackett disclosed that 23 batteries had been repaired or replaced in the first few months of 2017. Further, the company informed investors of its discovery that 10 more batteries were threatened by electrolyte impurities. Following this discovery Redflow reassessed its supply chain and sent 20 batteries to a lab for testing.

According to an email from Mr Hackett this testing revealed a supply chain issue, specifically a contaminant in one batch of raw materials. Without providing much detail (due to the secretive nature of the manufacturing process) the email suggested that this issue had been resolved and Redflow could resume business as usual in short order.

According to Redflow there is a strong demand for their product and the company has nearly $750,000 in backorders. The company recently announced its first foray into the lucrative telecom market, through Hitech Solutions, a New Zealand based telecom infrastructure company. Hitech has placed an order for $600,000 worth of batteries for remote island applications. While details are not forthcoming Mr. Hackett stated the deal “supports the first stage of a multiple-stage project.”