hey guys this is Frank and today we're going to talk about this
charge/discharge board that I built to process all 2100 of my 18 650 cells and
we're gonna do that right now all right guys this is the DIY engineer Channel
and on this channel we do everything DIY from concrete countertops to automotive
to construction currently we're working a bunch of 18 650 power storage projects
including power walls and portable power generators if you're interested in a
these topics please subscribe below and be sure and hit the little bell so that
you get notifications every time I post a new project or a new video around
these projects so with that we're to jump into this processing board for 18
650 cells that I built to process pretty much all the cells behind me where I was
thinking we would start with this is I have some previous video that I shot
when I was actually building this board it's kind of older and I really want to
apologize up front for the autofocus because the camera I was using was all
over the place had a hard time focusing but it'll give you a gist of some of the
processes I used to at least build the lower section of this board and then
when we come back I'll talk more about this upper section or what it took to
build that and why I did things the way I did so let's go watch those videos and
then I'll come back and we'll discuss this top portion okay I've been working
on this charging discharging table for a little while now and actually I had an
original it started here and I has calculated the size of the switch holes
and drilled them too big so I had to redo it now I have this that I'm working
on and hopefully this melamine is gonna work out really well I kind of liked
this shelving material these brackets seem to mount really well and they're
stout they're just really really stout on there so I'm hoping that this so
this'll help and I'll do a little tidbits of progress on this so that you
can see how it all comes together so all I'm doing now is just measuring out you
can see I measured out the edge here where this is the edge of the the
bracket itself of the holder and then I put a line here and here
to pour the pins that drop down at the bottom of the holder
so each holder has his pins that drop down and those holes or so just
perfectly so I can drop that right in there and then I just line them up and
then screw them down so that they're mounted nice and flush to the board very
clean and neat and tidy those lines go away they are no I mean just washes
right off so I have clean up really nice what's like I'm all done I'll just take
these off and wash all the lines off and it'll be good but all right go back to
mounting some more brackets and then I'll get started on the the charging
units and their switches all right I thought I would share how I actually get
this to this to this point when I started and mounted this Center one here
just perfect there's a center line that goes right up through the middle so I'm
able to take the center line and bring it right to the center of the of the the
holder so that way there I know that I'm at the center of the board my board is
25 inches wide and 16 inches deep so I have some room to work with it and I'm
hoping to get 28 charges across the bottom and then I got some discharge
units I should have 8 to 10 discharge units up on top so this will build a
handle pretty much the load that I'm hoping to put on it so how I got this to
this point how I figured this out what I did is I figured out where these pins
are way over here if you look the pins on the bottom or what Marsh solder
points is where the soldering is gonna go and I needed to determine where those
landed and so what I did is I drew some lines that
were very close to where those pins are so these lines here represent where the
pins need to go and then to figure this out all I did was mounted this or just
push this up against here and then I drew little marks right where the pins
are right now I'm just soldering up all of my TP 40:56 charging modules and
these will be connected on the backside I'll do a video here in the future where
you can see how I connect them underneath the the melamine here all of
these have been drilled marked and drilled specifically for these four
socket charging banks and then those will be bolted down to the board and put
in place and there'll be switches for each 4-pack so that I can turn them off
as needed when charging my my 18 650 cells right now I have hundreds of cells
I need to charge and I really need to get this done so that I can get them
charged I also have probably 200 cells that are ready for discharge so I'm
really needing this board right now and I just have a lot of cells to process
finally was able to get all of my charging units soldered and I just stuck
them through the holes so that they're they're not necessarily mounted down yet
but you can see how the wires go through in there it's nice and discreet and then
these here will um built mount Harold will put wires on these little clips
from the ends and then those will attach to the wires underneath am i Hardy I
have some of it together miss if I can lift this up and show you without doing
the mess here but you can see all the wires down there and how they come
through and then I'm using is these little brackets here focus there to
mount them together to bring the wires together and the reason I'm doing this
is so it's modular if I wanted to change out my my
holder's 19 650 yet battery hovers here I could put in different ones if I have
a unit that goes out because I'm an idiot and sometimes I've actually fried
probably about six of these just because I put a battery in backwards and one of
the things I'm experimenting with right now is using a MOSFET to cause it so I
don't if I put the battery in backwards it doesn't fry this unit or any of these
units but because I haven't gotten that mastered yet and worked out I'm going
ahead and just making these modular they're so inexpensive so it's not a big
deal if I burn one up but I just assume not if I can help it but anyways so
that's what it kind of looks like so far I've gotten several hours into this but
I'm quite pleased with that I think it's gonna work out really well my current
setup that I have that I'm using for charging right now consists of about six
units and and it's taking me a long time and I have a couple discharge units that
I'm using but they're not ideal so I'm hoping that this here will help solving
my issues one of the the things that I did get in today which I'm pretty
excited about are my resistors for for discharging I ordered these separately
see if I can get the focus here come on oh so these these resistors I wrote the
aluminum ones because I want them to be able to breathe I'm gonna mount them on
the back side and there we have fan underneath that will help keep them cool
just wanted to give you an idea of some of the work that I've done here so you
saw how I put in these charging units there's twenty eight of those and they
are each switchable so I can actually shut those on and off based on each bank
so every four cells has the ability to shut off by using the the main power
switches or these power switches here up here on the on the discharge section
this is used to determine how many milliamp
hours are in each cell so as I discharged them and make sure that each
cell before I even put it in here is charged to 4.2 volts and I need to make
sure that it's got the full voltage charge in it so that way there when I go
to actually run the discharge it will show the actual milliamp hours that I'm
shooting for and these for discharge units are tied to these four cells these
four to these four cell holders and these four discharges here to these this
cell set so that is the basic flow of it now what I'll do is I'm going to turn
the board over and let's take a look at the underside and you really can't
laughs cuz it it is a rat's nest under there but let's go ahead and take a look
at that alright so this is the underneath the board you have to
remember that this was kind of an experiment to see how things would work
out and so I've tried a couple different things you notice in my original videos
the old videos I actually had little bus bars in in between the the charging
units these guys here which you can't see and the actual cell bricks across
those 28 charging units across the bottom and those were working out okay
and I finally went back and just put in these bus bars and then just soldered
everything to bus bars so it simplified it by using I think this is just 14
gauge just regular electrical wire stripped out of just housing house wire
and just stretched in there works out really well to provide the voltage that
I need these these ports here I used a an old power supply
stripped down an old 80 power supply it was like a 500 watt power supply and
rerouted the five volt into here so these two here are 5 volt and this up
here is actually a 12 volt to provide power for the discharge units and I had
to do some step downs just to make sure that I kept the voltages consistent and
that's what these units are here I'm going to have a complete parts list in
the description below so you can look to that parts list to see you know where I
got everything and kind of get ideas on costs I got a little bit of money into
this but it's not too terrible I think that in the long run it all worked out
because I was able to process so many cells with this this table and it is
it's a mess so these over here are the MOSFETs I was
testing out to see if I could get it to save the cells problem I ran into with
using the MOSFETs it did work it kept me from burning out more of the charging
units a little charging units when I put it selling backwards because I'm an
idiot sometimes but the cost of these MOSFETs was almost
you know the price of having to replace all of the charging units and so to me
it was like yeah just be a little smarter and do it right so I left these
in here it was a good experiment one of the things I did find with these MOSFET
gates is they had a tendency I think to slow the charging rate down a little bit
I don't know why it would do that because it's really just a gate and the
cells didn't always charge up as high as I'd want them to I mean they would get
up around you know four point one five four point one two they just they
wouldn't get as high as I'd like as they did with the units where I didn't have
the MOSFET so I don't know that I would recommend it it's something if you
wanted to play with you could I did here and just found that it really came down
to it wasn't worth it to me these little disks these are the lot buck converters
allow me to take and drop voltages down so to go into
these units here I think they're they want a 5-volt continuous and so when I
was feeding power into those I needed to make sure that I dropped them down to
the right voltage so that I wasn't burning out those units those charging
units and the same for the the discharge units on the other side I had to take
and control the voltages there as well so there are step-down units for each of
those discharge units then you'll notice what I did is I wired in my resistors
for the discharge on the backside here that way there they weren't up and
exposed this worked out really well especially when I put these larger fans
you said these larger fans up on top that would blow on them so anytime I
turned on the power switch for specifically this Bank of discharge in
this Bank of discharge these fans came on and cooled down the resistors so that
they they stayed cool almost all the time they were it really worked out well
to have those fans on there and it didn't affect the discharge in any any
way that I could tell like I was terribly to get good good milliamp power
readings out of the the discharge units so that's kind of the the back end of my
board it is a rat's nest and I apologize for that
I will leave information in the description below where you can find all
of these parts if you found this video helpful please subscribe below and also
come visit my website at the DIY engineer comm and learn more about some
of the projects that I'm doing
thank you for watching I really appreciate your support just as an
update things have actually really taken off with my DIY channel I am finding
that within the last 90 days I've actually got 400 subscribers and my
views have really gone up higher than I thought they ever would this is
something I just never dreamed of happening it's I just wanted to share
but it looks like there really is an interest in 18 650 processing so I
appreciate the support and tell your friends subscribe click the bells so you
get updates and we'll catch you on the next video thanks for watching