New York (NY) - AT&T announced this week that it will replace 17,000 defective lithium ion batteries used mainly for professional purposes after the company that supplied them went bankrupt.

The batteries were used in outdoor equipment cabinets in the telecommunications industry, and were supplied by a company called Avestor. However, that company no longer exists. It filed for bankruptcy in October 2006, right around the time AT&T first started experiencing problems with them.

In about a year’s time, AT&T said it experiences two explosions and two full-on fires as a result of the faulty batteries. The batteries were mostly used as back-up power for AT&T’s U-verse TV network.

"Typically in this situation ... where we have four incidences we would do work with the vendor to diagnose the problem. We can’t do that in this situation because the company is out of business, which is why we made a decision to replace all these batteries," said company spokesperson Michael Coe.

AT&T said replacing the batteries will not affect its earnings forecast or its roll-out schedule for U-verse.