I recently finished restoring two old magneto phones from the 20's.
The require two 1 1/2 volt #6 batteries in each. I have been using two d cells in each to test but I want authentic looking batteries in each.
I want to make reproductions. You can actually buy these but at $40 each (I need 4) I think I will try this myself. I also want one to start my model airplane engines.
I was lucky enough to find someone who scanned the outside of a battery from 1925.
I have a body that is 2 1/2" dia and fahnestock clips for the top.
The original batteries were a single cell ... a very large single cell (zinc shell and large carbon rod in the center).
The reproductions you can buy have two D cells wired in parallel.
I can do this or I can fit in 6 C cells (all wired in parallel).
Which is better?
From what I can tell, D cells will supply 18000 mAh ... so 36000 mAh total.
C cells will supply 6000 mAh ... so 48000 mAh total.
I thought about sub c cells but I am not sure if the 1.5 volts vs 1.2 volts will make a difference in these phones (3 volts vs 2.4 volts). Plus since these phones will be used just once in a while for demonstration, the shelf life of alkaline batteries are 10 years ... I am guessing rechargeables will need charging every few months.
Anyway, my question is about internal battery resistance.
I don't know what affect the battery resistance has on a circuit?
I could not find a specification for the resistance of a #6 battery.
D cells have an internal resistance of 200 - 400 milliohms ..... so 100 to 200 if two in parallel ?
C cells have an internal resistance of 150 to 300 milliohms ... so 25 to 50 if six in parallel?
Just looking for some guidance.
Thanks .... Mike
The require two 1 1/2 volt #6 batteries in each. I have been using two d cells in each to test but I want authentic looking batteries in each.
I want to make reproductions. You can actually buy these but at $40 each (I need 4) I think I will try this myself. I also want one to start my model airplane engines.
I was lucky enough to find someone who scanned the outside of a battery from 1925.
I have a body that is 2 1/2" dia and fahnestock clips for the top.
The original batteries were a single cell ... a very large single cell (zinc shell and large carbon rod in the center).
The reproductions you can buy have two D cells wired in parallel.
I can do this or I can fit in 6 C cells (all wired in parallel).
Which is better?
From what I can tell, D cells will supply 18000 mAh ... so 36000 mAh total.
C cells will supply 6000 mAh ... so 48000 mAh total.
I thought about sub c cells but I am not sure if the 1.5 volts vs 1.2 volts will make a difference in these phones (3 volts vs 2.4 volts). Plus since these phones will be used just once in a while for demonstration, the shelf life of alkaline batteries are 10 years ... I am guessing rechargeables will need charging every few months.
Anyway, my question is about internal battery resistance.
I don't know what affect the battery resistance has on a circuit?
I could not find a specification for the resistance of a #6 battery.
D cells have an internal resistance of 200 - 400 milliohms ..... so 100 to 200 if two in parallel ?
C cells have an internal resistance of 150 to 300 milliohms ... so 25 to 50 if six in parallel?
Just looking for some guidance.
Thanks .... Mike
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