Topic: Batteries

[scottly]

Well...one of the things I learned when I worked building automated assembly equipment for companies like Gates Energy (now Enersys) and some other battery makers whom I can't name was: up until 2010, only Japan in the Far East made batteries with virgin purified lead (Yuasa was mentioned).

The telecom equipment I used to work with was all powered with 48VDC, with battery back-up. The standard was to have 8 hours worth of battery power in the event of a power outage, with larger offices having back-up generators to provide for extended outages. (Did anyone ever notice that even when the lights were out, the landline phone still worked?
In the late '80s, we had a lot of small, cabinet mounted remote systems, that had a capacity of 640 telephone lines, connected to the host office with T1 transmission lines. The cabinets were about 8 feet wide by 2 1/2 feet deep by 6 foot high, and included 6 strings of 4x12V, 25 amp-hour batteries in series to achieve the desired 8 hour capacity.
One of these remotes, which had only been in service for about a year, experienced a power outage, and the batteries failed after only one hour!! The vendor had started using Yuasa batteries, instead of the Gates Cyclon batteries they had used before, some of which had also suffered an early death, but never as early as the Yuasa. I was assigned to determine the cause, and found the temperatures inside the dark brown cabinets sitting in the desert sun to be a major factor. During my research, I did a load test on a new set of batteries on a remote that was being relocated, and was told to dispose of the Gates Cyclon batteries that had been replaced out of an abundance of caution. I "disposed" of them at my solar powered cabin, where they served me well for another 5 years.      

[HondaMan]

Well...one of the things I learned when I worked building automated assembly equipment for companies like Gates Energy (now Enersys) and some other battery makers whom I can't name was: up until 2010, only Japan in the Far East made batteries with virgin purified lead (Yuasa was mentioned).

The telecom equipment I used to work with was all powered with 48VDC, with battery back-up. The standard was to have 8 hours worth of battery power in the event of a power outage, with larger offices having back-up generators to provide for extended outages. (Did anyone ever notice that even when the lights were out, the landline phone still worked?
In the late '80s, we had a lot of small, cabinet mounted remote systems, that had a capacity of 640 telephone lines, connected to the host office with T1 transmission lines. The cabinets were about 8 feet wide by 2 1/2 feet deep by 6 foot high, and included 6 strings of 4x12V, 25 amp-hour batteries in series to achieve the desired 8 hour capacity.
One of these remotes, which had only been in service for about a year, experienced a power outage, and the batteries failed after only one hour!! The vendor had started using Yuasa batteries, instead of the Gates Cyclon batteries they had used before, some of which had also suffered an early death, but never as early as the Yuasa. I was assigned to determine the cause, and found the temperatures inside the dark brown cabinets sitting in the desert sun to be a major factor. During my research, I did a load test on a new set of batteries on a remote that was being relocated, and was told to dispose of the Gates Cyclon batteries that had been replaced out of an abundance of caution. I "disposed" of them at my solar powered cabin, where they served me well for another 5 years.      

Yep, the biggest enemy of the wet-cell battery's lead surface is elevated temperature. This was why, in the late 1970s and thru the 1980s, many Ford cars had insulator shells around the battery boxes under the hoods of their cars. GM and Chrysler didn't do this (except the top-line Cadillacs) and the batteries had to be replaced in less than 3 years in those cars. The Fords could run the full life of the battery, usually around 5-6 years. Heat makes lead plates much more porous, or I should say, makes the pores much bigger, which exposes them to the acid, makes the electrolytic change to the lead, and then when the lead cools it traps the change in an insulated capsule of molecules. This then loses that collection of molecules until the battery again reaches that temperature, or until the trapped acid damages (sulphates) those molecules of lead oxide for lack of circulation - which takes them out-of-service, so to speak. The Gates patent was/is the little rectangular cutouts in the lead plates that makes thousands of tiny captured acid-lead batteries in each plate: the wound-up versions (sometimes called "6-pack" batteries) have only enough acid in each cutout cell to service the charge that is captured there, so the lead recombines with the plate when discharged, preserving the molecules without oxidation during the discharge cycle. They are almost dry, so there is no extra acid to further damage the lead, and sulphation becomes impossible. It takes many years and power cycles to eat the thin lead "frames" of each rectangular cutout, so those batteries often last for decades, at any temperature. Cool stuff.