OT: 12 D cell battery backup

[Chuckt]

Our ISP upgraded our speed to FIOS and they got out of the battery backup business. We use to have a lead battery that lasted about eight hours and there was a button to press which would give you about 20 minutes of reserve to call emergency services if the power went out. They took all of that away.

They offer a box that holds 12 D cell batteries. According to the paperwork, "The pack has integrated storage capacitors with an On/Off switch and space for 12 standard D-Cell Alkaline Batteries in one compact enclosure. It provides an output of ~8~10W with a wide 10~20 Vdc output range for a wide ambient environment (-20C to 60C)."

Anyone can see below for a picture of it:

https://www.verizon.com/supportresource ... ctions.pdf

https://www.verizon.com/support/consumer/battery-backup

I'm wondering what other uses this device could be used for. I find it interesting and I wonder how long 12 D Cells can power the phone.

[brad]

That seems an odd way of doing things. Why not just use some sort of lithium ion battery pack which can be recharged by a USB port? Although it seems that they are against using rechargeables because they specifically tell you not to use them... Perhaps this is due to the lower voltage per cell?

[Chuckt]

Most people have cell phones. My neighbor doesn't have a land line but she has a cell phone.

Lithium batteries are great but I've found the AA batteries just suddenly give out and I know that heat can affect a lithium battery's performance.

There are the occasional lawsuits:

http://wvrecord.com/stories/510605681-l ... -batteries

The cost of being in the lead acid battery business is that you have to have it delivered to a facility with a Hazmat driver. You have to have a 704 sign and room designed for hazardous materials. You have to have a MSDS on site. That opens you up to inspections from Licenses and Inspections and the Fire Department and possible fines. You have to be licensed to do that.

I didn't know how to open the old lead acid battery box from Verizon but they know how to get into it real easy.

By offering a battery box, they give the customer the first 12 batteries but they eliminated the lawsuits, the licenses, the room, environmental cleanup, shipping and receiving, transportation and storage space.

How long will D cell batteries last on the shelf without using them? I think they will easily last one or possibly two years before you have to check them.

Before if your battery was dead, that would be because of a storm and then many people had that issue when the utility was checking on the wires. You can't just go out to any store and buy a lead acid battery. You have to have inventory levels. By making the customer responsible by purchasing them, you basically don't have to pay someone at the company level.

In a storm, you can have power out for eight hours or more. When your power is out, the battery charge level goes down and there is a failure rate. It happens on cars; someone leaves the lights on and then your battery is dead and then you need replacement. When the power level is down too long, the battery physically starts to die as well. When you have 500,000 residents or 1,000,000 residents or more, how many batteries do you have to replace? You would have to know the failure rate. The problem them becomes how many batteries are available and from where and what are the factory lead times? Do you have to get them from other warehouses in other states? And then companies don't like looking bad in the eyes of their customers if they can't get enough batteries or if the customer has to wait. Customers can become irate and when they are irate, it isn't beneficial to a company. Remember, this happens when the utility is probably busy checking the phone lines because trees are down or wires in the ground may be flooded. This happens when they are already busy and trying to restore service while serving customers through customer service. The less they have to do the better.

The question is, if you were a customer for a company and had to go out to the store to buy a lead acid battery of a certain size, where would you get it? And you can think of your local auto store and your local hardware or retail store. Are there enough batteries available after a storm for everyone if there are 1,000 failures?

So if you are an electrical engineer for industry, this is a lesson for designers. Our designs need to be what the customer wants and what the company wants but some designs are not economically sustainable because it makes the business model less efficient.

[Garth]

There are lead-acid D cells too, but I know you said "alkaline" in the first post. I wish lead-acid batteries were available even much smaller.

We recently built a solar backup for the event of power going out (a possibility which appears to be increasing), and I had to learn more about batteries and fuses and inverters and things than I ever wanted to know. http://batteryuniversity.com/ is a great place to learn. We have Interstate deep-cycle flooded lead-acid golf-cart batteries, and from what I've read, they'll last 20 years if you take care of them. Reviews from owners who have been using them for ten years say they're still working great. (I think that after I've had it for 20 years, I'd forget to write a review or that the same model wouldn't be in production anymore.) That involves things that a car doesn't have though, primarily with the intelligent charge controller, including charge voltage profiles, equalizing, de-sulfating, having a temperature sensor on the battery, and cutting off the load if the voltage gets down low enough to start damaging the battery. The sealed ones used in alarms or wheel chairs won't fare nearly as well, and their amortized life cost in cents per kWh is about ten times as high as what these golf-cart batteries will cost.

[Chuckt]

I think the battery box for our land line charges capacitors because there are instructions that I have to load the batteries in a certain order and then I have to take them out in reverse order when replacing them. I'm afraid of damaging something and it's not something you want to have to remember when the power is out.