Rechargeable Lithium Ion Sensor Custom PCB
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If the arduino is outputing 3.3v that means that you are powering the arduino with the RAW pin, isn't it ?
If so make sure the linear voltage regulator on the arduino will be able to provide the 3.3v if battery voltage drops below 3.3v (so from 3.3v to 2.8v). I don't think they can boost the voltage from 2.8v back to 3.3v :( -
If the arduino is outputing 3.3v that means that you are powering the arduino with the RAW pin, isn't it ?
If so make sure the linear voltage regulator on the arduino will be able to provide the 3.3v if battery voltage drops below 3.3v (so from 3.3v to 2.8v). I don't think they can boost the voltage from 2.8v back to 3.3v :(@akumar said:
make sure the linear voltage regulator on the arduino will be able to provide the 3.3v if battery voltage drops below 3.3v (so from 3.3v to 2.8v).
That's not necessary - for this case you have the battery measurement circuit as mentioned in my previous post.
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@akumar said:
make sure the linear voltage regulator on the arduino will be able to provide the 3.3v if battery voltage drops below 3.3v (so from 3.3v to 2.8v).
That's not necessary - for this case you have the battery measurement circuit as mentioned in my previous post.
@HenryWhite said:
That's not correct. You are mixing up something. The RAW pin is for unregulated power input. With this you can bypass the internal voltage regulator. When you use the normal VCC input, the voltage will be regulated to 3.3V, if the input is (depending on arduino model) between 3.3V and 12V.
It is actually the other way around. From https://www.arduino.cc/en/Main/ArduinoBoardProMin :
If you're supplying unregulated power to the board, be sure to connect to the "RAW" pin on not VCC.
Power on RAW pin results in the regulator being in use.
Power on Vcc bypasses the regulator. -
@akumar said:
make sure the linear voltage regulator on the arduino will be able to provide the 3.3v if battery voltage drops below 3.3v (so from 3.3v to 2.8v).
That's not necessary - for this case you have the battery measurement circuit as mentioned in my previous post.
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@HenryWhite said:
That's not correct. You are mixing up something. The RAW pin is for unregulated power input. With this you can bypass the internal voltage regulator. When you use the normal VCC input, the voltage will be regulated to 3.3V, if the input is (depending on arduino model) between 3.3V and 12V.
It is actually the other way around. From https://www.arduino.cc/en/Main/ArduinoBoardProMin :
If you're supplying unregulated power to the board, be sure to connect to the "RAW" pin on not VCC.
Power on RAW pin results in the regulator being in use.
Power on Vcc bypasses the regulator.@mfalkvidd said:
Power on RAW pin results in the regulator being in use.
Power on Vcc bypasses the regulator.indeed. seems like I mixed up something there :D
I will update the eagle files when i have time to. -
So if I sum up, powering this node with a single Lipo cell will work by connecting the Lipo to the raw pin on the arduino. This will work from 4.2v to 3.4v. This is not that good for the battery life.
Using 2*AA batteries with a boost converter seems a lot easier...
I'm almost giving up on this idea : I liked the flat form factor of the lipos and they were solar pannel friendly. Is there a way to use a voltage regulator from 4.2v to 3.4v and then switch the circuit to a boost converter from 3.3v to 2.8v ? -
So if I sum up, powering this node with a single Lipo cell will work by connecting the Lipo to the raw pin on the arduino. This will work from 4.2v to 3.4v. This is not that good for the battery life.
Using 2*AA batteries with a boost converter seems a lot easier...
I'm almost giving up on this idea : I liked the flat form factor of the lipos and they were solar pannel friendly. Is there a way to use a voltage regulator from 4.2v to 3.4v and then switch the circuit to a boost converter from 3.3v to 2.8v ?@akumar It's the same problem as with all lipos. But you have to consider that it will take a really long time until the battery hits 3.4V or less. There are even smartphone batteries with 3000+ mAh which are very small.
Also it seems to be good for battery lifetime when the voltage does not drop that much compared to using a step-up converter below 3.4V.
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So if I sum up, powering this node with a single Lipo cell will work by connecting the Lipo to the raw pin on the arduino. This will work from 4.2v to 3.4v. This is not that good for the battery life.
Using 2*AA batteries with a boost converter seems a lot easier...
I'm almost giving up on this idea : I liked the flat form factor of the lipos and they were solar pannel friendly. Is there a way to use a voltage regulator from 4.2v to 3.4v and then switch the circuit to a boost converter from 3.3v to 2.8v ? -
Looking at discharge curves I can see that I should be able to squeeze 75% of the battery capacity if I charge it back when it reaches 3.3v. On a low power node this could work.
@flopp The reason I was mentionning 2.8v is because the battery protection module will kick in at this voltage. But you're right, no reason to go this far.Thanks !
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Looking at discharge curves I can see that I should be able to squeeze 75% of the battery capacity if I charge it back when it reaches 3.3v. On a low power node this could work.
@flopp The reason I was mentionning 2.8v is because the battery protection module will kick in at this voltage. But you're right, no reason to go this far.Thanks !
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Sure ! The newer ones have a battery protection chip. I've tested it and it kicks in at 2.8v.
http://www.aliexpress.com/item/Free-Shipping-10pcs-lot-1a-lithium-battery-charging-18650-with-protection-one-plate-protec-2-in/1876166772.html -
@flopp said:
Now I see, there are pads for battery and pads for out. Looks good
Correct. The old Tp4056 modules do not have the OUT terminals (and therefore won't fit on the pcb I designed in this thread)
@akumar said:
On a low power node this could work.
Why should it only work on a low power node?
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hi.
"Why should it only work on a low power node?"
with time we will have more and more things to charge every week/day (phone, watch, iot...), so I would say : for less maintenance ? lol
more seriously, it is a nice project I will follow it ;) I have one board to order (not ordered yet) with a li charger but mine is definitely not diy (too small chip so it is for stencil use).
Mobile phone batt is a very nice idea :smiley: I am a more confident than cheap lipo..and I have some old cheap galaxy s2 batt..How do you plan to hook the battery to your board? -
hi.
"Why should it only work on a low power node?"
with time we will have more and more things to charge every week/day (phone, watch, iot...), so I would say : for less maintenance ? lol
more seriously, it is a nice project I will follow it ;) I have one board to order (not ordered yet) with a li charger but mine is definitely not diy (too small chip so it is for stencil use).
Mobile phone batt is a very nice idea :smiley: I am a more confident than cheap lipo..and I have some old cheap galaxy s2 batt..How do you plan to hook the battery to your board?@scalz said:
How do you plan to hook the battery to your board?
As smartphone batteries are usually fully enclosed, I will just stick the battery (I will use the galaxy s4 batteries) under the pcb.
The whole package should fit nicely in a 75x75x40 distribution box, which will only cost a few cents in your local hardware store.
Only downside of the boxes is that they are a bit ugly :D
But since I don't have a 3D printer yet i will go with that solution and maybe paint the boxes black or white. -
cool.
I am building my 3d printer actually because I want custom things (not too much ugly) ;)
I was talking about how to wire between the batt and the board. So you will solder wire on it?
but it is not a big a problem I think, if I use these sort of batt, maybe I will try to find some contacts and handle this in the custom box.see you soon :)
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cool.
I am building my 3d printer actually because I want custom things (not too much ugly) ;)
I was talking about how to wire between the batt and the board. So you will solder wire on it?
but it is not a big a problem I think, if I use these sort of batt, maybe I will try to find some contacts and handle this in the custom box.see you soon :)
@scalz said:
I am building my 3d printer actually because I want custom things (not too much ugly) ;)
I thought about that too, but then I saw how much calibration, try&error etc. you need to assemble your own 3D printer. And after that it's still a hassle to get prints with good quality.
Because of that I will just save money for the ultimaker 2.. :D@scalz said:
I was talking about how to wire between the batt and the board. So you will solder wire on it?
Yes, I will solder the contacts of the battery directly to the tp4056 module. Because you don't have to replace the battery (until it breaks) this method should be fine.
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:+1: it makes sense too.
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"Because of that I will just save money for the ultimaker 2"
yep but calibration, try&errors, settings.. are always there, even if you have a 2000 dollars printers. no plug and play, it is some kind of myth for the moment that people don't know before buy one. but lot of people are working to improve commercial or diy printer.
For instance, I did some orders on 3dhub. Some were printed with prusa or ultimaker, pla or abs... And sometimes I got better quality from a prusa owner than ultimaker owner. One box was dark burnt on ultimaker, it was not good. So it is a matter to well know the stuff ;)
and then it is very proprietary (filament, settings, software...).
I have talked about this with some fablabs people who have expensive printer (ultimaker, zortrax for instance) and diy corexy printer. That is why I am building my corexy which cost to me 300€ and I know every angle of it ;). Some learning curve, which expensive printer have too, but then no more proprietary&co problem..just my point of view...
