Old FAA document on dry cell battery recharging

Dr. Jones

Newly Enlightened
Joined
Oct 7, 2023
Messages
137
Location
Princeton, New Jersey
I came across this document a while ago; thought that it might be of interest to some here:

https://apps.dtic.mil/sti/trecms/pdf/AD0620018.pdf

Dated 1965, it's entitled Feasibility of Recharging FAA In-Service Dry-Cell Batteries, and was compiled by the FAA's Systems Research & Development Service.

The document contains bits of arcane information on several obscure or obsolete battery types, but its main focus is on the recharging of carbon-zinc dry cells with an eye towards keeping them in service longer. Ultimately, however, the study concluded a program involving the recharging of carbon-zinc cells wasn't worth following, but instead recommended that alkaline batteries be regularly recharged, up to 40 or 50 times, after shallow discharge.

Hope that you find it of interest.
 
Last edited:

PhotonWrangler

Flashaholic
Joined
Oct 19, 2003
Messages
14,529
Location
In a handbasket
Dry cells are a misnomer. They're technically damp cells, and a common failure mode is when the electrolyte dries out.

A long time ago I read that one could rejuvenate some dry cells by drilling a shallow hole near the bottom on two sides, then sitting it in a cup of water for awhile to rehydrate the electrolyte. I tried this, and it actually worked to some degree. It also made a mess with all that carbon.
 

Dr. Jones

Newly Enlightened
Joined
Oct 7, 2023
Messages
137
Location
Princeton, New Jersey
They're relatively dry, compared to a flooded battery. ;)

I seem to recall hearing long ago that one could rejuvenate a dry cell battery by drilling an exceedingly small hole in bottom, off to the side, and injecting a solution of water mixed with the tiniest bit of detergent as a wetting agent into the electrolyte; I've never attempted it myself.
 

PhotonWrangler

Flashaholic
Joined
Oct 19, 2003
Messages
14,529
Location
In a handbasket
They're relatively dry, compared to a flooded battery. ;)

I seem to recall hearing long ago that one could rejuvenate a dry cell battery by drilling an exceedingly small hole in bottom, off to the side, and injecting a solution of water mixed with the tiniest bit of detergent as a wetting agent into the electrolyte; I've never attempted it myself.
Interesting. I never heard about the detergent trick though.
 
Top