Dry Cell Batteries?

[Old Timer]

There's an alarm company near me who has 12volt dry cell batteries to give away. These come from alarm systems and are changed annually. Could they be used for storage?

[crashk6]

What type of "dry cell" are they? NiMH or NiCd can be used but you have to build a charge controller to meet their respective charge profiles. Although some commercial charge controles already have NiCd charging built in, like Trace/Xantrex models (by cutting a resistor) or Outback controllers can be programed for them.

Although I must say in most of my experience with alarm systems, at least here in the states, they use small sealed lead acid batteries. Which of course will work...

But as I don't know Ah capacity or the actual type of battery were discussing all I can provide is speculation.

My guess is if these are around the size I'm thinking they would be fine for small stuff, but not very practical for a house sized storage bank.

Can you add more information?

--

crashK6

[Bruce S]

Old Timer;

 Ooooh, used to get hit when I said that as kid.:-))

Are these the Gates Cylon type? I've seen the 2V "D" size units put together as 12-dry-cell sets. We change them out for SLAs.

 I would take them since "Free" is always good.

If they are the Gates type, check each one for voltage above 1.2v if they don't have that call a recycler or whom ever you know. These unlike NiCds and such will not come back to life by using a desulftor. And once they go below the 1.6v threshold they will not come back. I have 15 of the 2volt Gates rated at 2.5Ah each and I have tried everything to get them back up and nothing worked. Even took them to a "Battery" manufacture and they told me the same thing.

Not sure what they're made from but if get the and they're good , keep'em charged and they'll last for ever, I'm told. This is the same type the old wireless radios had in them.

Hope this helps;

Bruce S

[drdongle]

I can tell you right now that these will be 12 V gel cells mostly 4 and 7 AH and if their greater than 4 years old worthless. I have worked in Security and Fire detection off and on for years, "dry cells" haven't been used for many years.

[ghurd]

I have some 12V 5~7AH gel- cells well past 5 years old. Spiffy for LEDs and testing stuff.  That is what I use in the house.

Not good for long term storage because of age, or power because of size.

Mine were removed from service from big-box store cash registers.

Great for solar night lights, etc.

"Give away" means free, right?

Free is good. I like free.  I bought mine.

A VW panel, a few LEDs, a CDS cell, Ta-Da!

Cheap and workable nightlight. Reading light. Etc.

And wally-world gives me core charge, regardless of AH, for battery purchases.

Give wally 2, 12V, 7AH batteries for 2, 6V 220AH batteries. Feels good.

Sometimes you have to say 'Here is the core.'  The guy doesn't care, a core is a core. Some places may even pay cash for the core.

'Dry Cells'. I haven't seen one for 30 years. Giant 8x3" toilet paper tube with 2 bolts on top. Not rechargable. Pretty sure they were at K-Mart at the time.

Think big, non-alkaline, nonrechargable, D battery, made of paper.

[kell]

now called Hawker Cyclon

[Ungrounded Lightning Rod]

Actually, carbon/zinc dry cells ARE rechargable - IF they haven't discharged enough to have sprung a leak (which happens BEFORE their output voltage drops) and IF you use a charger that rapidly cycles between a charging current and about a 10% discharge current (like a half-wave rectifier system with a resistor across the diode).  This was figured out about the time they were becoming obsolete, replaced by alkalines.

The back-and-forth current is to smooth the surface of the zinc plate:  Charge 'em continuously and the concentration of the field builds metal up on the high spots and less on the low ones, roughening the surface and leaving the almost-eaten-through parts thin.  But the discharge current is even MORE selective about REMOVING metal from the high spots more than the low, so the cycling makes things smooth out.

Not efficient for energy storage, of course, since you throw away much of the charging energy to smooth the plates.

The caveat about springing a leak is because dry cells use the negative electrode to contain the electrolyte paste.  When the cell gets near discharge it starts to get holes and the corrosive material leaks out - and is thus out of place for attempting to recharge.  (The "sealed in steel" versions do this too - inside an outer can.  The can is just to protect the battery-powered device from corrosives.  It doesn't make the batery reusable once the zinc plate develops holes.)

[highv]

hey ungrounded lightning

is there any other website which talks about recharging dry

cell batteries.?