Paul & Sabrina's cheap DIY 144v motor controller

[Grimm]

Originally Posted by MPaulHolmes

I ordered the parts for one little battery monitor for Lithium cells. I have my little voltage regulator in the garage (0-3amp, 0-30v) that I'll simulate the cell sagging and charging. ya!

I figured that if I had $20,000, and I could aeromod a car, that I could probably get 200watt*hr/mi, and about 310 miles of range.

Hey all, I've been reading this thread for a while and finally decided to post. I have a '92 GMC Sonoma (Basically an S10) that I plan on converting to electric after I build a Cougar controller.

In response to the above post, I happen to have 500+ 18650 Lithium cells that I salvaged from a set of identical laptop battery packs that were lightly used (I do a lot of computer salvage hehe), which I charged and balanced with a Bantam BC8 charger. So Paul, if you need some cells to fry... I mean test! your BMS on I wouldn't mind shipping you 50, 100, 200 cells, loaning you the charger, or sending you some output data from it so you can charge lithiums without them asploding (taking a blowtorch to a dead cell is quite exciting!)

Also, for anyone out there looking for a computer for EV related stuff I can probably hook you up with one without too much trouble... just don't expect it to be new. I'm hoping to start building a control board sometime in the next month... any major hardware changes in the pipeline I should wait for?

Hope to be of some help to somebody

[etlaare]

500+ ? omg.. I only need 30 and have no idea where to find them .. any hints ?

[MPaulHolmes]

Hi Grimm! My goodness. Let's see. The BMS is for a pack of Thundersky batteries. Those are Lithium Iron Phosphate. Do you know the charging algorithm for Lithium ion? I wonder how similar it is. It will be a little while before I make the charger. It's 6kW, so that would be a bit much maybe for 18650 cells. hehehe.

As for new and fancy control boards, I know Adam is working on some stuff, and those crazy Australians (MCUDogs. hehe) have done all sorts of awesome things. Also, I'm going to do a surface mount version as well as a Synchronous rectification version. I finally will have a little money because we have a son! Hurray Taxes!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! So I'll be able to send the layout stuff to the PCB company. Oh the joy and rapture...

[Grimm]

Hey Paul, I'm not sure how close the charging curve is. I think I can get a pretty good idea of how it works if I discharge a set then use the usb hookup to plot out volts and amps while it charges. If that works then I might try the same thing with some AA nimh bats I have around. I also have some lead acids but those have a really simple charge curve. If I get my hands on some lifepo4s from a drill pack I can plot those too, I don't know if the big EV ones charge differently other than the C rating which I'd assume would be bigger.

[jeffd94]

Originally Posted by MPaulHolmes

Hi Grimm! My goodness. Let's see. The BMS is for a pack of Thundersky batteries. Those are Lithium Iron Phosphate. Do you know the charging algorithm for Lithium ion? I wonder how similar it is. It will be a little while before I make the charger. It's 6kW, so that would be a bit much maybe for 18650 cells. hehehe.

As for new and fancy control boards, I know Adam is working on some stuff, and those crazy Australians (MCUDogs. hehe) have done all sorts of awesome things. Also, I'm going to do a surface mount version as well as a Synchronous rectification version. I finally will have a little money because we have a son! Hurray Taxes!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! So I'll be able to send the layout stuff to the PCB company. Oh the joy and rapture...

Hello Paul

Go to this web site, Mondo Technology - Pic Projects

this guy has a PIC Li-Ion battery charger project.
It may help you with some ideas that you may have.

Cheers

Jeff

[adamj12b]

Hey Everyone,

Finally got around to posting about progress on my surface mount control boards. Ive been very busy with school and work.

I was able to get almost all of the passive components ( Resistors, Caps) installed and reflowed.

I was hoping to have this done sooner, but the parts turned out to me more expensive then I thought, not too much, but it is about $100 for the 2 boards, not counting the resistors. I was waiting for some important parts to come back into stock in the US also. Now that everything is instock that is needed, I will hopefully be ordering the stuff in the next few weeks as I save the money.

Well, for features of this board there is HV voltage sensing, built in pre charge control, and dual outputs to drive 2 driver boards and pusedo power supplies for the outputs.

Here are some pics and a video of the reflowing.

-Adam

http://www.youtube.com/watch?v=Bx5OFXNRuow

[etlaare]

That looks so neat.

I always wondered how such small components could survive such high temperatures for so long though ...

Do You compare the pack voltage for the pre-charge or is it just a timer ?

[mrbigh]

Cool, I want to sign-up NOW for a controller board for my IGBT powered equipment.

[adamj12b]

Originally Posted by etlaare

That looks so neat.

I always wondered how such small components could survive such high temperatures for so long though ...

Do You compare the pack voltage for the pre-charge or is it just a timer ?

They have been manufactured to handle the heat of reflowing.

The pre-charge isn't much different then what is in place now. It just has some safety circuitry, resistor and relay all onboard. It will still use the pc-time setting in the controller to control when the controller closes the contactor, but you wont have an external resistor, or relay. The safety circuit doesn't allow the contactor to close if there is still pre-charge current still flowing.

The bus voltage measurement stuff will be able to be used to enable things like motor voltage limiting and for data output for graphing to sense sag. We should also be able to enable some form of LVC too.

Originally Posted by mrbigh

Cool, I want to sign-up NOW for a controller board for my IGBT powered equipment.

Soon. lol real soon. I will be able to have them rapidly populated if I get enough orders together. These 2 boards were not worth the hassel of putting all the different value parts into the feeders and then the feeders into the machines. BUT, if im making a panel or 2 at a time, that will be totally worth it.


On a side note. I am currently working on developing an expansion board that will bring all these new features that have been added in hardware to the users with the original control board. It will be a simple connection to the main board with a 6 pin ribbon cable that will attach to the ISP connector that is in place.

On this board, I will be including the precharge circuity, bus voltage measurement circuitry, and I was thinking a tach pulse input from motor with a tach pulse output to drive an in-vehicle tach with software scaling so that it will display the right RPM. What do you think?

-Adam

[esoneson]

I think you better check outside to see if people are starting to line up outside your front door (even in the snow) for these boards!!

Very exciting compliments to the Cougar design.

Great work.

Eric

Originally Posted by adamj12b

On this board, I will be including the precharge circuity, bus voltage measurement circuitry, and I was thinking a tach pulse input from motor with a tach pulse output to drive an in-vehicle tach with software scaling so that it will display the right RPM. What do you think?

-Adam