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I thought I would share some data on my experiment. I know that this is not what most of you are doing and may not have any relevance but for anyone interested I wanted to start a post to share my test runs.
The equipment used is the 3-pole from r-charge. I have made my own circuit board using 1N3957GP transistor and MJL21194G diodes ( same on BtoE and from C). The base resistor is a 100 Ohm 1watt Metal-Oxide. I have a 12v 60ma lamp in series from the base to the resistor and then to a 1k pot. It is nothing special, the circuit is laid out just as the circuit on the original monopole diagram. I am only using the one transistor and feeding all three coils in parallel to it instead of the original 3 transistor circuit that came on the kit.
What I am charging is a pack I made from an old drill battery. I removed 3 cells and made a pack. I thought this would be about 3.6v but it actually is a bit higher. In te attached picture I have laid just a single cell out so you can see what the 3cell pack is constructed from.
My primary is a 17AH SLA. I know everyone uses equal batteries on front and back for proper testing but for now I am just trying to learn about the charging that the machine does and this tiny pack on this particular machine seems to respond very well for that purpose. I am also thinking to make small rechargeable lights for myself and this is the right voltage that I am looking for. I recharge my primary from a small solar panel I made from individual cells. It puts out about 13.6v in bright sun.
I am attaching a charge curve I ran on this pack. The machine was set to draw .12A at the beginning and it held nicely at that rate for the first 3/4 of the charge. I noticed towards the end it started bouncing up to .14 and then back down, almost like a flicker. You can clearly see this in the green areas where it pops up quite a bit. This could have been the POT acting up or maybe the battery responding to the charge, I really don't know. Regardless I did not touch the POT and just let it run fixed the whole time.
The total charge time was 2 1/2 hrs and at the end I cut the primary and let everything settle while still attached to the meter. The battery rested at about 4.12
Next I am going to run a 2 1/2 hr discharge curve on it to see what that looks like which I will post also.
*EDIT*
I ran the discharge (attached)
The load is a high power LED 3watt rating. I put a 2 Ohm resistor on it for protection. When I first loaded it I took a reading of .33A and this decreased as time went on. I though it was pretty interesting how it dipped real far at about 2 hours but then continued for a very long time. The light obviously was diminished greatly after that dip but it was still shining dim the entire rest of the cycle. I expected it to cut off when it started dipping or soon after but that did not happen. I'm not sure of the forward voltage on the diode but I think it is about 1.9V. I decided to end the test before it ever reached the cut off.
I am going to run this same test several more times. If anything interesting changes I will post back. I am already thinking that if I want to use this LED for an actual portable light I will probably make another 3 cells in series and then parallel that with this pack. It seems the voltage is fine but the capacity is weak.
Anyway this is just a test to see what I can do with this kit. It does not charge larger batteries very well at all but it seems to love these little Ni-Cads.
Discharge was about 12Hr's
The equipment used is the 3-pole from r-charge. I have made my own circuit board using 1N3957GP transistor and MJL21194G diodes ( same on BtoE and from C). The base resistor is a 100 Ohm 1watt Metal-Oxide. I have a 12v 60ma lamp in series from the base to the resistor and then to a 1k pot. It is nothing special, the circuit is laid out just as the circuit on the original monopole diagram. I am only using the one transistor and feeding all three coils in parallel to it instead of the original 3 transistor circuit that came on the kit.
What I am charging is a pack I made from an old drill battery. I removed 3 cells and made a pack. I thought this would be about 3.6v but it actually is a bit higher. In te attached picture I have laid just a single cell out so you can see what the 3cell pack is constructed from.
My primary is a 17AH SLA. I know everyone uses equal batteries on front and back for proper testing but for now I am just trying to learn about the charging that the machine does and this tiny pack on this particular machine seems to respond very well for that purpose. I am also thinking to make small rechargeable lights for myself and this is the right voltage that I am looking for. I recharge my primary from a small solar panel I made from individual cells. It puts out about 13.6v in bright sun.
I am attaching a charge curve I ran on this pack. The machine was set to draw .12A at the beginning and it held nicely at that rate for the first 3/4 of the charge. I noticed towards the end it started bouncing up to .14 and then back down, almost like a flicker. You can clearly see this in the green areas where it pops up quite a bit. This could have been the POT acting up or maybe the battery responding to the charge, I really don't know. Regardless I did not touch the POT and just let it run fixed the whole time.
The total charge time was 2 1/2 hrs and at the end I cut the primary and let everything settle while still attached to the meter. The battery rested at about 4.12
Next I am going to run a 2 1/2 hr discharge curve on it to see what that looks like which I will post also.
*EDIT*
I ran the discharge (attached)
The load is a high power LED 3watt rating. I put a 2 Ohm resistor on it for protection. When I first loaded it I took a reading of .33A and this decreased as time went on. I though it was pretty interesting how it dipped real far at about 2 hours but then continued for a very long time. The light obviously was diminished greatly after that dip but it was still shining dim the entire rest of the cycle. I expected it to cut off when it started dipping or soon after but that did not happen. I'm not sure of the forward voltage on the diode but I think it is about 1.9V. I decided to end the test before it ever reached the cut off.
I am going to run this same test several more times. If anything interesting changes I will post back. I am already thinking that if I want to use this LED for an actual portable light I will probably make another 3 cells in series and then parallel that with this pack. It seems the voltage is fine but the capacity is weak.
Anyway this is just a test to see what I can do with this kit. It does not charge larger batteries very well at all but it seems to love these little Ni-Cads.
Discharge was about 12Hr's