DIY Charging Supply PSU for ISTA+ BMW Programming

[NoQuarter]

Get these two printed and adjust again. Just guessing on the screw holes and such. When I am pretty close then I'll see about making the screw holes with the correct taper/diameter for a specific screw.

Seems the bezels should go in with a screw and washer/bolt on the inside or an inside matching bezel to accept the screw from the front side.

Air Vent - simple pattern as this is my first time

Interested to see how well the raised lettering works out for this one

 

[fmorelli]

I love seeing this. Great progress!

So on the air vent ... problem with 3D printing it that way is that you've eaten up a lot of space for air flow. Do you have ability to print a mesh that is maybe 0.030" or so? Another thought to consider - you could make the screen area open with an inset - make a two-pieces - frame and screen inset - so you can cut the stainless mesh. Once inserted the screen into the frame and pressed in the insert you could epoxy or super glue the insert into the frame. Then screw the whole shebang up.

Couple other thoughts - for the Powerwerx connectors, I might suggest looking at how far the connectors stick out from the box. I didn't really like that so much on my version - I think they are exposed to be hit. Looking at what you are doing, I think there could be an opportunity to create a bezel which diminishes the protrusion of those connectors. Maybe the metal bracket supports screw into the bezel from the back (with an relief for the metal thickness)? Just a thought.

Couple other thoughts - I read "VIN" so to speak, and "Vout" ... yeah I'm dumb. Of course then immediately figured out what that meant.

Nice work. Really like how you are approaching this!

Filippo

 

[NoQuarter]

Good idea on trying to correct how far out the powerwerx connector is. I'll give that a go on the next iteration.

 

[fmorelli]

Good idea on trying to correct how far out the powerwerx connector is. I'll give that a go on the next iteration.

Check clearance on the counterpart connectors that come from the battery cable side. Curious to see what you determine

Filippo

 

[NoQuarter]

 

[NoQuarter]

Big thanks to @fmorelli for having the electrical connections and much of the hardware ready to go for me - quality work!

Testing of the supply is up next

 

[fmorelli]

I love the 3D print approach. More work than it looks, but one benefit should be that anyone else that would like to do this can have 3D print files for the custom parts. I suppose had we done all of this in 3D print, the aluminum u channel rail could have been replaced with a 3D print solution as well. .... for the next person to tackle!

Nice work @NoQuarter !

Filippo

 

[fmorelli]

Finally under way with some testing. We've had a few issues, but working through it.

 

[Traf]

Clean work !
May i ask why we can't use old dumb battery chargers ? Got one for cheap that can push 25A at 15v.

 

[aus335iguy]

Recommendation for flashing modules is for 50A

 

[fmorelli]

And if you go to later/other models (I have an E70, had an F10, but F series etc) we jump up to 80A and more, requirements wise.

 

[Torgus]

And if you go to later/other models (I have an E70, had an F10, but F series etc) we jump up to 80A and more, requirements wise.

No ICE car should ever draw 80A or need a PSU capable of it for coding, Jesus.

 

[NoQuarter]

Don't we have 200amp alternators?

 

[fmorelli]

Don't we have 200amp alternators?

So .... if we build an outboard motor that we connect to the alternator with a belt drive, we've solved the problem?

 

[nsjames]

this is significantly nicer than my $20 version made with a dell power supply and old jumper cables soldered directly to it.

A simple high quality 12Volt 100Amp Power Supply- Part1 - RC Groups

A simple high quality 12Volt 100Amp Power Supply- Part1 Batteries and Chargers

www.rcgroups.com

is a vast repository of power supply conversion knowledge.

 

[fmorelli]

Yes we used the rcgroups for some of our information. I'm almost done testing (been a busy week) but still have some minor teething pains to sort out. I started with my Zero Turn mower - LED lights. Worked great. If I try to start the mower, though (28HP dual OHV) the PSU shuts itself off. Power off/on and it comes right back up. I then moved to my old 2001 Ford Powerstroke. If I disconnect batteries and just run on the PSU ... no problem with headlight high beams, 10A draw. If I move the key to position 2 ON (not start), the PSU again shuts itself off. If I have batteries connected, no problem running up to a 50A draw.

I've noticed two issues, I believe:

First off - I think the PSU has a protection circuit that looks at ramp up rate of current (is that like a slew rate?) Simply I have no issue if batteries are connected.

Second - I'm seeing a voltage drop. If I set the PSU to 13.8V, and then say I'm drawing 50A on the truck, I see about an 0.5V drop in the current, to 13.3V. I'm not sure if that is showing some kind of parasitic loss?

Planning to hook it up to the X5 on Friday, batteries connected, and turn on a bunch of stuff and see how it goes.

 

[fmorelli]

One other thing - there are other choices for shrinkwrap flash reprogramming chargers. For example, Schumacher makes one. But I've seen a bunch of complaints about customer service, and these things some times shitting the bed. Those are $600+ ... which is not ridiculous, but for that price I want it to work and I want a company that stands behind the product - I'm unconvinced of either with Schumacher.

The nice part about the PSU DIY is ... discrete components. Second, those server PSU's are about as industrial as one can get. If one shits the bed - if any component shits the bed, easy to diagnose, cheap to swap in and replace.

 

[nsjames]

Yes we used the rcgroups for some of our information. I'm almost done testing (been a busy week) but still have some minor teething pains to sort out. I started with my Zero Turn mower - LED lights. Worked great. If I try to start the mower, though (28HP dual OHV) the PSU shuts itself off. Power off/on and it comes right back up. I then moved to my old 2001 Ford Powerstroke. If I disconnect batteries and just run on the PSU ... no problem with headlight high beams, 10A draw. If I move the key to position 2 ON (not start), the PSU again shuts itself off. If I have batteries connected, no problem running up to a 50A draw.

I've noticed two issues, I believe:

First off - I think the PSU has a protection circuit that looks at ramp up rate of current (is that like a slew rate?) Simply I have no issue if batteries are connected.

Second - I'm seeing a voltage drop. If I set the PSU to 13.8V, and then say I'm drawing 50A on the truck, I see about an 0.5V drop in the current, to 13.3V. I'm not sure if that is showing some kind of parasitic loss?

Planning to hook it up to the X5 on Friday, batteries connected, and turn on a bunch of stuff and see how it goes.

they all have some sort of overcurrent protection.

your lawnmower starter probably draws 100amps instantaneously, it's not gonna like that.

Try loading the 5v rail and see if the 12v rail comes back up with a load.
I've had ATX power supplies in the past I've converted and some of them need something on the 5v rail or the 12V rail won't perform.

 

[nsjames]

here's my much cruder variant.
stable at 13.6v @ 50A.
no load voltage is set to 14.1 with a resistor.

It usually somewhere around 13.8 with the average 25a loads my junk presents.

I read somewhere that 13.2 is supposedly the minimum voltage, so after I checked it at a current level that trips the OCP at 13.4 I just figured it was good enough and sent it.

It hasn't been a problem.

 

[nsjames]

other cheaper retail power supplies can be had from the ham radio world.

Amazon.com: TekPower TP50SW 50 Amp 13.8V Analog DC Power Supply with Cigarette Plug: Home Improvement

Amazon.com: TekPower TP50SW 50 Amp 13.8V Analog DC Power Supply with Cigarette Plug: Home Improvement

www.amazon.com

also a ham radio nerd.
general nerdery in my household.
I have their 25 amp version for a bench power supply and it worked previously to do coding and such, but I could see that it wasn't just quite enough when you powered up everything in the car.