Hey Guys - I'm looking for something like these in the links below. They more or less supply a clean voltage (no spikes that can damage sensitive automobile electronics), adjustable voltage output, and can supply lots of amps when coding modern vehicles electronics. Any suggestions on what to use? Wish I could find something less expensive.......

https://www.toolsource.com/misc-c-31...-p-253657.html

https://www.jbtools.com/midtronics-m...SABEgL88_D_BwE

 

I don't like the first one and the second one is excessive.

Just how many amps do you think you need for "coding electronics"?

A smart charger is the way to go now. Produces enough amps for demand and will drop down o a trickle charge when not needed. A smart charger was recommended at the Navistar dealership I worked at when doing reflashes.

 

I forget the amps requirement off the top, but it was pretty high, 70 or 90. one of those 2 figures. seems like 70 is more common. I've ran across accounts of guys turning computer P/S into chargers for this purpose, but would be nice to find a "reasonable" priced unit. The more expensive one can be had at amazon for 700, but OMG, just for a dang battery charger??

 

I agree 100% that both of those units are overpriced for what they are , but with that said something to consider when comparing them to a good old fashioned battery charger is this ; the battery charger of old was a really simple device consisting of just a transformer and a rectifier with maybe an amp meter if your lucky , and they put out some pretty "dirty" DC (unfiltered , with loads of AC ripple) . The units your looking at are able to (supposedly) put out between 70 and 100 amps of pure DC with none of the AC ripple associated with the old time chargers* , this extra filtering (capacitors and chokes) plus the microprocessor control makes this more than just a battery charger , it's a specialty power supply unit VS the old time charger , and thus they figure they can charge a specialty price for them .

* It is this reason you can't use an old battery charger to test a car radio without using a car battery , the unfiltered DC causes a loud hum in the speakers .....

 

Understood. Here is what one guy is using. Saves a few bucks. https://www.digikey.com/products/en?...ds=RPB-1600-12

 

Found it!

This is what the Navistar dealerships recommend to use when reflashing ECMs. Still not cheap but does the same thing as those other expensive ones you listed.

https://navistarservice.snapon.com/S...umber=PSC550CC

 

Thanks, I think it can be had for $300
Problem is it is not adjustable, output looks like it is fixed at 13.4V, and supplies 55A

 

IMO, you dont need a battery charger, you need a 12V DC power supply (with clean power).
Why do you need lots of amps?? ......that makes no sense for 12V powered electronics, which have a very low amperage draw.
This should be all you need....

 

It depends on what you are programming at the time. Sometimes several ECU's on the car engage at once and you need to be able to supply the amps required. 70A can occur, but not typical. Different cars have different voltage requirements, for example, it appears GM is expecting 13.4V while BMW expects 14.4V during the programming of ECU's. that power supply you posted would be perfect, but it needs to be able to provide more current.

EDIT: The last thing you want to do is brick an expensive ECU by not providing the proper power.

 

I'm sorry but I disagree with what you say.
There is NO WAY programming several ECU's at once will require 70 AMPS - Impossible
Maybe 7.0 amps, but certainly NOT 70.....just aint NO WAY

 

BTW - I deal with very sensitive electronics (Avionics systems) on my aircraft - nothing requires 70 AMPS
That is insane to say, do you know what gauge wire you'd need for 70 amps ???? It would be like the size of the battery cables going to the ECU's

 

lol - I used to design Avionics. There are guys who actually measure their amp draw while programming their cars. I read accounts of very high amp draw.

 

Think about what you are saying......what gauge wire are all the wires going to the ECU ???
70 amps would smoke those wires in seconds, heck, 30 amps would smoke them.....

 

I have no idea how many amps might be drawn during this procedure - fast forward to 1:30 mark.

 

BTW - here is the equation/logic: switching power supply powered by 120 VAC mains. So, roughly. 40 Amps x 12 VAC is 500 Watts. 500 Watts / 120 VAC is only 4+ Amps

 

That suspension leveling is so cool!

It takes very little current for an ECM to power up. Most the current consumption are "sourcing" output drivers firing injectors and other devices. However, the ECM might actuate a relay that is on a circuit that consumes quite a bit of current. Things like electric steering, prelube pumps, fuel pump, vacuum pumps, etc. So I guess it depends whether you're flashing an ECM, or doing diagnostic tests. The diagnostic tests could consume a decent amount of current depending what features are on the car, and how many things are active at the same time.

 

ya, I dig that leveling, i have it on my E60. makes that 4500 lb tub ride like its on rails!

 

I agree, we are talking about 2 very different things - Flashing an ECM takes virtually no current draw, even several ECM's at once.
But even diagnostics testing will only draw high current for a couple micro seconds (usually) sustained high draw current (as in your 70 amp example)
I highly doubt. Like I said, if the circuit required sustained high current, the wire gauge for those circuits would be substantially larger.

 

I use for my RC car chargers PC power supplies cheap easy to convert and gives you choices of very clean 12, 5 & 3.3 volts.
This is a link to one site showing how to build it.
power limit is based on what the rating of the supply you get.

 

thanks, didn't get the link

 

trust me, i felt like you when I first started this journey. the repair manual specifications say otherwise tho. look my post a few above that gives the equation. we're talking about 12 - 14 volts, not 120.

 

That's fine,.....whatever you think
Good luck with it.....
BTW - 120 volts has nothing to do with it, that is meaningless in the equation, all 120V does is power the unit your using for a power supply (the PS has a 120V input).

 

I program BMW's, yes, they do require a 90 amp charger for those questioning it, and they absolutely must maintain voltage or programming will be paused, and the whole ordeal is fragile enough as it is when things are going well. My advice is to get the best one you can afford if you are doing bmw's and mercedes. I can get you the brand of the one I use at work tomorrow. We upgraded the cables to a super heavy duty set, and they get warm. Do a lot of F chassis and sometimes they can take 2-3 hours or more to program. Its not something that those who haven't used ista or gone through the process on these cars usually understand.

 

I thought we were talking about flashing an ECM on a 3rd gen.....when did this turn into a BMW system programming discussion? I am not on the same page as you guys here....

 

BizJetTech , I took this quote of LiquidBlue's from the first post in the thread to mean that he was talking about other than our 3rd gens , when he mentioned "Modern Vehicles"

 

Yep, missed that early on.....guess I assumed we were talking about a 3rd gen being this is not a "modern vehicle" forum.....just sayin

 

I hear ya biz , I understand that the premise is always supposed to be third gen , and if newbies go off the third gen topic it's usually frowned on , but every so often when a regular poster asks an off topic question I'll give an answer if I feel I can help .

 

So I gotta ask.....what is the system circuit protection fuse size in these BMW's ??? Certainly not 70 amps ??? I think the test equipment being used comes into play here....

 

So just curious , were did you get your A&P , Embry Riddle ? I got mine in 1980 at East Coast Aero Tech . Ok , yeah , so I'm old

 

cool, another old fart like me.... Gateway Tech - 1985 FAA A&P / IA & FE

 

I understand that it may not be exactly third gen related, but this is the tech forum and occasionally there are some smart or experienced individuals here, which is why I suppose the OP asked his question, and he can still use said charger on his third gen lol. The amount of current required to program modern cars has nothing to do with the test equipment. The programming laptops run on their own supply, and absolutely nothing is left in the vehicle during the process. There can be 40+ modules on modern vehicles, and during the programming process, different functions will be ran automatically (you cannot program just the dme on a bmw, you have to program the whole car). Things like cooling fans, lights, power windows, seats, etc. Sometimes the programming time remaining will tell you up to 24 hours, sometimes I've gotten an infinity symbol. You need a power supply that can keep up. If you're just using hp tuners or tis on an older gm to program the ecm, you don't need anything exotic. If you are programming new vehicles, and especially german vehicles, the charger isn't something you can skimp on, and it has to be able to maintain 14+ volts cleanly during high current demand. Again, not trying to get too far off the TGO topic, but just providing a little education.

 

I get it now that we are talking about the total amperage load for the entire car, (and a newer BMW, not a 3rd gen) not just one specific circuit in the car.... I thought the OP was saying one circuit was pulling 70 amps....we are talking about programming the entire car (newer BMW) so yes, I can see this now....

 

https://www.electronics-tutorials.ws...ch-supply.html
does help if I remembered to attach the link

 

Thanks for the link!

 

Thanks matt, would appreciate any recommendation you may have.

Yes, this thread is a wee off topic, but I know there are a lot of smart guys over here and why I asked. Not to mention the charger can be used on our cars too and in fact it would be better. Why send electrical noise thru our precious 3rd Gen car electronics when you don't have to. I know what ever I end up buying/making, I will use it for my Formula, rather than that old Craftsman charger I have laying around. No need to unplug the battery to charge it up with these bad boys.