VapCap Induction Heater for Desktop and in Car Use

DeeCee5

DeeCee5

Livin' La Vida Loca in FL
io_wait

io_wait

Member
Thanks to everyone in this thead and the forums for documenting all the IH builds :) Spent last week reading all 99 pages, making notes and planing.
Last weekend I took the plunge and built my own induction heater, inspired by Pipes (and u/crossfires) designs.
OcwZcVV.jpg


It's powered by a heavily modified PC power supply that can deliver 12V 25A on each of the two ports (the other one powers my desktop e-cigarette).

Next step is a portable version and that's where I hit a snag.

I'm looking at the BMS board that is commonly used for IH builds with LiPo packs or 18650 batteries in 3s config. I get that it has low voltage cutoff and all that.
What I don't understand is why @Pipes uses an external 12.6V charger. The BMS has a built in charge controller and can stop charging the cells at 12.6V balanced when supplied with 13V.

What am I missing here? Please help me understand what's going on.

*edit* imgur album with more pictures https://imgur.com/a/Kw4NbaR
 
R

rz

Well-Known Member
@io_wait welcome to FC! :) Glad you're getting in on the DIY action.

Li-po cells need to be handled with a little extra care. There's a region of safety where the cell can comfortably accept charge, and out of that 'zone', the cell will deteriorate much faster (/ too fast?).

LiPo's are typically charged in two main stages - constant current (the ones typically used here are charged at about 0.5A~1A.. depends on the cell, thermal solutions, etc), up until a certain charge point, then 'constant voltage' - where the current will tapper down to a minimum as the cell voltage rises, and then stop charging after a timeout or certain minimum charge current is reached
(more info : https://batteryuniversity.com/index.php/learn/article/charging_lithium_ion_batteries )

The BMS will just enforce a few of those safety nets like per cell under / over voltage / short circuit protection, but will not do anything to control the charge rate and cycles - a job left to the charging solution of your choice.
 
io_wait

io_wait

Member
Thanks for the warm welcome :)
I know about LiPo battery safety, been working with e-cigs and the like for about 2 years now but wasn’t aware that the BMS mostly used here doesn’t do CC/CV charging.
According to some documentation I found it only does charge cutoff at 12.6V it seems. That explains my confusion.
To be honest, I’ll probably look for a better BMS that also takes care of charging and wire everything to USB-C since I love running everything from USB-C PD ports (so far: Laptop, Phone, Tablet, soldering iron). That’s going to be a hard...
 
io_wait,
R

rz

Well-Known Member
@io_wait let me know when you find a good chip :)

the BMS under/over voltage is "per-cell", so the charge cutoff will be when ANY cell hits the value... dunno what chip model it is (usually there are tens of varations of each model actually), but usually around 2.5V/4.2V.

You could find chips that'll boost 5V, or support PD. I'm using a MP2639A for a 2S solution, and I've bypassed it's discharge function since I'm not interested at 5v/3A out anyway. There are more advanced chips around, though it'll be a lot of effort to get it working right. If you're doing it for fun or a production run, awesome! :) Otherwise, you may be better off putting your efforts elsewhere..
 
QueefMonkey

QueefMonkey

Well-Known Member
Hey folks! I am one of the lucky few that received Pipes Skeletor Kits, so I took it upon my self to find the perfect enclosure (IMO) for it. Here are the fruits of my labour after scouring the internet for hours. I hope yall enjoy!

Special mention to Pipes for doing all the hard work for us! ;)

https://imgur.com/a/Kc1UTAl

PS- i cant seem to embed pictures to the post, can someone tell me how to? i tired using the editor and adding "image" URL to the post with no luck.

Thanks!
 
Last edited:
Summer

Summer

Long Island, NY
QueefMonkey said:
Hey folks! I am one of the lucky few that received Pipes Skeletor Kits, so I took it upon my self to find the perfect enclosure (IMO) for it. Here are the fruits of my labour after scouring the internet for hours. I hope yall enjoy!

Special mention to Pipes for doing all the hard work for us! ;)
script>
Click to expand...

There's a problem using imgur on FC. Here's 2 threads offering alternative pic sites:

http://fuckcombustion.com/threads/please-stop-using-imgur.33374/#post-1295052

http://fuckcombustion.com/threads/what’s-up-with-imgur.29564/

Your custom case is very sleek & posh. I like that you an see the innards through the top. I like it a lot. :clap: How did you manage to drill the holes without cracking the plastic?
 
Summer,
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Edgedamage

Edgedamage

Well-Known Member
Ok my latest build is almost conplete, I am waiting on a timer circut for a MOT spot welder. Then I can make a custom fitting 3s battery pack from 18650's. The system was tested using a external battery pack. This build is called the R2D2 cup build:

I used the parts from the coffee can build the dents where bugging me. View from the back:
This build includes a 3S charging module, which has a input voltage range of 13-20vdc. I have charged with a 19vdc laptop charger, and a 13vdc 1.3amp wall wart.
 
QueefMonkey

QueefMonkey

Well-Known Member
Summer said:
There's a problem using imgur on FC. Here's 2 threads offering alternative pic sites:

http://fuckcombustion.com/threads/please-stop-using-imgur.33374/#post-1295052

http://fuckcombustion.com/threads/what’s-up-with-imgur.29564/

Your custom case is very sleek & posh. I like that you an see the innards through the top. I like it a lot. :clap: How did you manage to drill the holes without cracking the plastic?
Click to expand...

Thanks for the info! Here are some more pictures. 3 flute step drill set did the job for the lid ;)

20180821_171418.jpg


20180821_171359.jpg


20180821_171352.jpg
 
Pipes

Pipes

Addicted DIY Enthusiast
Accessory Maker
Yes, I have. It's identical to the regular driver, except one less choke coil. This means that the work coil must have a center tap to function. Which would be an addition wire going halfway into the windings. The board itself is identical and in fact, one can rewire the normal board to be like this one as the holes are already there. Notice the driver connectors have three connections. We do not use the center for a normal work coil but the center tap goes the center connector in a single choke coil configuration. Funny how they charge more for less...lol and they don't even include a work coil like the regular one does.
Have fun!
 
D

DataRocks

Well-Known Member
This is the project I've been working on. It is powered by an arduino nano, and has "manual" and "automatic" modes. The automatic mode just tries to take the vapcap to a specific temp and then automatically shuts off. Currently testing several different automatic modes, including a record/play mode.

In action in Manual Mode:

https://streamable.com/rhnqs



aBHEeCy.jpg


rOBKqiL.jpg


srMMM4r.jpg



Temp in Automatic Mode:
Green Line is the Shutoff limit, at first it has a high value. There is a first manual cycle to calibrate the device, that brings the green line down. Blue is the vapcap temp, red is the sensor temp (for safety).
Currently working on a mode that "records" the temp graph and then tries to replay it.

ChtjDHu.png
 
DataRocks,
Hackerman

Hackerman

User
Awesome dude. I have a couple arduinos in the drawer. When you get it all tweaked, maybe post the code? Looks great.
 
Hackerman,
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