Charger with finish voltage setting
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kreisl
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i am testing a prototype of such a charger. very nice!
tandem
Enlightened
So called hobby chargers tend to allow for this sort of flexibility, but typically are limited to charging single cylindrical cells at a time. You can create a parallel charging rig out of a cell holder.
A drop-in charger with the ability to set termination current or target voltage, with on-board LCD live read out, would be sweet.
A drop-in charger with the ability to set termination current or target voltage, with on-board LCD live read out, would be sweet.
have any info you can share?
closest thing I saw was this DIY option: http://www.electro-labs.com/diy-lithium-battery-charger-shield-arduino/
They might release a kit but right now its purely diy including the PCB.
So there really isnt any option for a drop in ready to go charger that can do this?
Thanks for the tip. I have an entry level hobby charger from my RC days and it works pretty well but I'm looking for something that is more "put together". When I use my hobby charger I have to set up a cradle and wires with alligator clips. I'd like something that is a little more out of the box ready to go.
kreisl
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You're probably talking about LiIon batteries? It makes imho less sense to manipulate termination voltages with NiMH batteries.
My MC3000 prototype sample would be a drop in ready to go charger, i had posted its user-set finish voltages here.
Funny thing, some cheap chargers can be modded to do this very easily.
I have a charger I've used for years, and found out it was over charging my batteries a bit.
Cut off a 4.25v causing it to flash bulbs in certain incan lights of mine.
I had to figure out by necessity how to fix it.
Turns out the termination voltage was set by a single resistors value. Change the value, change the cut off.
The clue was in the fact that it was a dual purpose li-ion / lifepo4 charger.
It has a switch to select between the two.
That switch simply changed the resistance on that circuit.
So, it takes some tech know how, but certain chargers can be modded to do this.
I have a charger I've used for years, and found out it was over charging my batteries a bit.
Cut off a 4.25v causing it to flash bulbs in certain incan lights of mine.
I had to figure out by necessity how to fix it.
Turns out the termination voltage was set by a single resistors value. Change the value, change the cut off.
The clue was in the fact that it was a dual purpose li-ion / lifepo4 charger.
It has a switch to select between the two.
That switch simply changed the resistance on that circuit.
So, it takes some tech know how, but certain chargers can be modded to do this.
Yes, liIon. I was just reading up on that charger. Looks promising!
Thanks for that. I have a couple chargers with the switch. I'll poke around and see what I can find out in my older chargers.
For now it looks like im sticking to the hobby charger on the LiLo setting:
Metal collar stays with magnets make great impromptu bus bars
I'm also considering doing a DIY based on this projecT:
http://electronics-lab.com/projects/motor_light/020/index.html
The IC is programmable for 4.1V.
Metal collar stays with magnets make great impromptu bus bars
I'm also considering doing a DIY based on this projecT:
http://electronics-lab.com/projects/motor_light/020/index.html
The IC is programmable for 4.1V.
One might question if this effort is all worth it ?
Cell aren't exactly expensive and hard to find now days. Use them until they wear out, than get some more.
Chances are they're going to last a lot longer than you think.
Honestly, I've been running Li-Ions for over a decade now, and I still have cells that I got years and years ago, and have used regularly, that are still healthy.
I know for sure I have this one AW IMR 18650 that I used in my EDC for like . . . 8 years . . . it takes has most of it's capacity and cranks out the amps, AND, that was in an unprotected Incan light, where I would often run the battery down, AND, that was using that charger I was talking about that over charged to 4.25v.
Cell aren't exactly expensive and hard to find now days. Use them until they wear out, than get some more.
Chances are they're going to last a lot longer than you think.
Honestly, I've been running Li-Ions for over a decade now, and I still have cells that I got years and years ago, and have used regularly, that are still healthy.
I know for sure I have this one AW IMR 18650 that I used in my EDC for like . . . 8 years . . . it takes has most of it's capacity and cranks out the amps, AND, that was in an unprotected Incan light, where I would often run the battery down, AND, that was using that charger I was talking about that over charged to 4.25v.
That was what I was thinking and why I sold my hobby charger since I don't have any RC toys. I ended up designing my own charger that gives me a lot of flexibility and adjustability. You can see it in this thread........post #43 for completed unit.
http://www.candlepowerforums.com/vb...n-battery-charger-gt-suggestions-needed/page2
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That's a cool set up!
I'm actually waiting for some pcbs to come in for a simple charger based on the max1811 IC. I designed it with two sets of jumper pins, one for selecting between 4.1/4.2V and one for 100ma/500ma charge current.
Not as fancy as yours though!
Have you shared your PCB and schematic anywhere?
Sent from my iPhone using Candlepowerforums
I have some extra boards if wanting to build up something. All the parts were bought at either Mouser or Digikey. The LTC4053 is similar to the Max1811 in that its a USB charger but with a slightly higher output capability and adjustable charge current but fixed at 4.20v +/- its tolerance.
The charger that takes a 12v input utilizes a buck switching regulator where I feed both voltage and current back as the feedback to the converter IC using op-amps wired in an "OR" fashion. Therefore which ever is the higher voltage does the regulating. At first its CC (constant current) and then it becomes CV (constant voltage). I wanted something that I could use in the car or with a solar system without having to convert 12 v down to the 5v USB level. It accepts a wide range of input voltage and is slightly more efficient than the USB version. With a USB charger you will have the power loss with the voltage difference between the 5v usb and the battery. With the switcher the output voltage is always just slightly above the battery voltage. Since the 12v charger is discretely designed, it's flexible in what the termination voltage is set to.
Anyhow happy to talk shop and share ideas if you'd like.
The charger that takes a 12v input utilizes a buck switching regulator where I feed both voltage and current back as the feedback to the converter IC using op-amps wired in an "OR" fashion. Therefore which ever is the higher voltage does the regulating. At first its CC (constant current) and then it becomes CV (constant voltage). I wanted something that I could use in the car or with a solar system without having to convert 12 v down to the 5v USB level. It accepts a wide range of input voltage and is slightly more efficient than the USB version. With a USB charger you will have the power loss with the voltage difference between the 5v usb and the battery. With the switcher the output voltage is always just slightly above the battery voltage. Since the 12v charger is discretely designed, it's flexible in what the termination voltage is set to.
Anyhow happy to talk shop and share ideas if you'd like.
