I have a couple old big box "C" batts from a past restoration. One a Ray O Vac, the other from Gamble Stores. Both still measure close to original -4 1/2 and -3V. Can these be restored to original value with just a drop or two of water like bias cells. Are they valuable as is, or with new batts and copied cardboard case?

marv

Marv, these are dry-cells, right? I'm not sure how you could rejuvenate them. Even though their open-circuit voltage is OK, I would suspect that the voltage would drop when supplying a load. But the thing is, C batteries don't supply any current, just bias voltage. So, they should be good as is.

Yeah, somebody might want the batteries for display or for salvaging their cardboard wrappers.

I'm thinking that Gambles has been out of business for maybe 30 years or so?

:Marv, these are dry-cells, right? I'm not sure how you could rejuvenate them. Even though their open-circuit voltage is OK, I would suspect that the voltage would drop when supplying a load. But the thing is, C batteries don't supply any current, just bias voltage. So, they should be good as is.
:
:Yeah, somebody might want the batteries for display or for salvaging their cardboard wrappers.
:
:I'm thinking that Gambles has been out of business for maybe 30 years or so?
:
Trust me, NOBODY is going to believe this, but I had a friend who would heat up dry cell batteries-in a FRYING pan!!!! He would actually get several more hours out of them, enough to keep something like a remote going long enough to get a replacement. If I hadn't seen it, and measured the voltage myself, I wouldn't believe it either.

WARNING- that said, NEVER do this because the batteries COULD explode.

I'm just including this as an interesting comment.
Terry

Terry,
Many years ago my brother and I would do the same warming trick, but sans fryin pan. Just close to a heat source.

marv

::Marv, these are dry-cells, right? I'm not sure how you could rejuvenate them. Even though their open-circuit voltage is OK, I would suspect that the voltage would drop when supplying a load. But the thing is, C batteries don't supply any current, just bias voltage. So, they should be good as is.
::
::Yeah, somebody might want the batteries for display or for salvaging their cardboard wrappers.
::
::I'm thinking that Gambles has been out of business for maybe 30 years or so?
::
:Trust me, NOBODY is going to believe this, but I had a friend who would heat up dry cell batteries-in a FRYING pan!!!! He would actually get several more hours out of them, enough to keep something like a remote going long enough to get a replacement. If I hadn't seen it, and measured the voltage myself, I wouldn't believe it either.
:
:WARNING- that said, NEVER do this because the batteries COULD explode.
:
:I'm just including this as an interesting comment.
:Terry
:

Doug,
At least one specifically says heavy duty Zinc. What were the button bias cells, zinc, mercury or something else?

marv

:Marv, these are dry-cells, right? I'm not sure how you could rejuvenate them. Even though their open-circuit voltage is OK, I would suspect that the voltage would drop when supplying a load. But the thing is, C batteries don't supply any current, just bias voltage. So, they should be good as is.
:
:Yeah, somebody might want the batteries for display or for salvaging their cardboard wrappers.
:
:I'm thinking that Gambles has been out of business for maybe 30 years or so?
: