DSL provides boost for Ni-Cd batteries

International battery vendor SAFT says the accelerating rollout of DSL services in the U.S. is persuading operators to switch from traditional lead acid power backup to nickel cadmium in street cabinets, huts and controlled environmental vaults.

After three years of trials with Telcordia Technologies, SAFT is a privileged partner for Pacific Bell/SBC's access network program, involving major asymmetrical DSL deployment. SAFT Ni-Cd batteries already are being deployed in Pacific Bell/SBC networks in Connecticut and California.

SAFT acknowledges that the entry cost for Ni-Cd power can be up to three-and-a-half timers higher than the high-grade valve regulated lead acid (VRLA) alternative. However, if life-cycle costs are considered, Ni-Cd batteries start to have a better cost profile between one-and-a-half and three years in service, depending on the grade of VRLA unit to which they are compared, said SAFT telecom marketing director Antoine Brenier.

"In the same operating conditions, the maintenance-free internal of Ni-Cd batteries can be longer than the entire life of a VRLA battery," Brenier said.

SAFT is targeting the U.S. DSL sector with the argument that Ni-Cd batteries' superior reliability and predictability over a wider temperature range chimes well with the "always-on" pitch of DSL service providers. The siting of remote DSL cabinets close to subscriber residences also raises the issues of potential acid damage and explosion in the case of VRLA batteries, Brenier said.

SAFT estimates the global market for telecom backup batteries is growing at around 12% per annum and will be worth $1 billion this year. The company hopes to command up to 6% of this market next year (Global Telephony, April, page 52). In addition to DSL, it believes that Ni-Cd technology is a good fit for mini-cellular base stations, some larger base stations and central offices in locations where temperature extremes are normal.