Hey Sternwake! Something of interest and questions...

[Lafnbug]

http://www.alcad.com/Products/Ni-Cd-Single-Cell-batteries/LD-P-MP-Range-Single-cell

I have a source for a bunch of these ALCAD MP80 batteries (used, institutional setting), they are Nickel-Cadmium. From what I gather they are 1.43v each, have over 20 years of service life, and can be discharged to virtually zero with no ill effects. I'm thinking about tinkering with 12 of them, but I can't figure out what charging regimen will make them happy, or what total amp hours they are each.

Whaddaya think?

 

[Optimistic Paranoid]

Did you notice in the MSDS sheet that in the event of fire, you needed a Class D Fire Extinguisher, and Fire Fighters should be wearing Self-Contained Breathing Apparatus? Sure you want to mess with used batteries with those kinds of characteristics?

Regards
John

 

[Lafnbug]

There may be NOS extras to be had here as well. They store for many years if properly done.

 I worked in a plastics factory in a former life, and my best advice in ANY fire with modern materials is: LEAVE ASAP. Burning plastics contain serious toxins. In fact, there's nothing that I know of that is healthy to breathe once burning. Not wood, nor any other plant material, nor even wax candles (even bees wax!). In a fire, would a lead acid battery be any safer?

I know some fire extinguishers can get pricey; I will look into this. But if they were that bad, why would they be occupying several floors of a hospital?

 

[Optimistic Paranoid]

I know some fire extinguishers can get pricey; I will look into this. But if they were that bad, why would they be occupying several floors of a hospital?

If there is some technical reason why a hospital feels they NEED to use technology like this, the hospital can afford to have professionally engineered fire suppression systems built in to the room in which they are located.

Plus, the engineers who installed the batteries themselves understood EXACTLY what they were dealing with.  They didn't have to guess about how to charge them without overcharging them, which would - I'm guessing - probably be a bad thing.

It ain't my job to try to talk you out of this.  If you decide to go ahead, Good Luck.

Regards
John

 

[Lafnbug]

You raise good points, as usual! I do appreciate your input, and I will definitely research this!

Thank you!

 

[SternWake]

I do not know much about NiCads, But I'd be as leery of them used as I would be leery of a used lead acid battery whose history was unknown.

http://batteryuniversity.com/learn/article/charging_nickel_based_batteries

 

[ccbreder]

NiCad batteries were the go to rechargeable before LiFePo. Flashlights, portable tools, phones, shavers, almost anything electric operated or stand-by. The biggest problem, they develop a memory of short discharge cycles and gradually have a very short cycle time. They are as safe as any battery pack can be safe.

 

[jimindenver]

We used NiCads when I use to fly and the packs would get memories. We used cyclers to remove that memory and quick chargers keeps the down time to a minimum. I haven't flown in a decade but I still use those NiCads.

 

[MikeRuth]

Jim and I concur, Nicad batteries will develop a memory. It's a proven fact. I'm surprised as Nicad tech has been fading out in favor of new chemistry.

I have power tools using nicad packs and I'm careful to keep them charged when sitting but still see a short life span compared to liPo and LiFe and other newer chemistry. I make sure to purchase Nicads with a current manufacturing date yet still see them as a short life. Almost if not all portable power tool manufactures have switched to Lithium-Ion packs. That type of chemistry has a incredible minute self discharge, I have seen packs sit from fully charged for more than 6 months and deliver 95% of there rated capacity with no ill effects.
Granted the manufactures do say that they should not be fully charged and left to sit. I have no idea what there charging scheme is by these manufactures. If they actually charge them to 95% then they will have a fantastic life span.
In the hobby instead of charging my TX packs to 4.2 volts per cell I charge to 4.1 I have packs three years old working as new. The flight packs that get charged to 100% have a typical life of one to two years.
This is reflective of all lithium-Ion batteries today.

Mike R