[GnomeChild]

Hello Post,

Decided it's time to get off my ass and stop procrastinating/hoarding mods and actually install them. Quite a bit of my mods require coding to be finalized and I almost have my laptop VM setup for such.

One last piece of the puzzle is figuring out which battery power supply to go with?

I think I remember someone specifying that I need a supply that cranks out at least 50v or w (I don't remember which) to ensure my car doesn't shut off in the middle of coding. I have quite a bit of heavy coding days ahead of me and my car doesn't get driven enough so my battery is always in somewhat of a state of constant discharge.

I hopped on Amazon to buy a supply quick, but admittedly I have no clue what I'm looking at/for. What is everyone using or recommending?

[335i54n]

if u got a good battery (done the 20min one several times, now wireless is minutes), you really dont need one. otherwise at least a 10amp unit

[GnomeChild]

Originally Posted by 335i54n

if u got a good battery (done the 20min one several times, now wireless is minutes), you really dont need one. otherwise at least a 10amp unit

I need one because I plan on doing an iLevel update and that is a minimum 1 hour flash with ICOM; 12 hours or more possibly with K+DCAN

[JB20DGM]

I bought and used a Midtronics PSC-550S when I updated all the modules (except for the FRM and CAS) in my 325. It seemed to do just fine and I had no issues. I'm sure there are other, less expensive, options that would work just fine as well. Either a "big enough" battery charger or I've seen a couple of smaller battery tenders hooked up in parallel to get the job done.

[int_c0m8U$tion]

This is what I use and it’s about as cheap as you’ll want to go. Unfortunately voltage regulators, at least good ones for programming and coding work, are not cheap. Nor do you want to risk it.

PowerMax PMBC-75 75 Amp 12V Battery Charger with Clamps https://a.co/d/0016fU5

If you’d like to splurge this is the unit I’d be after.

Car Battery Charger TOPDON T90A, 90Ah Smart Automotive Charger Battery Maintainer&Desulfator with 12/24V Output, 5A-90A Adjustable Charging Current, ECU Programming Stablizer for Boat Mariner Truck https://a.co/d/bepzZnG

[GnomeChild]

Originally Posted by int_c0m8U$tion

If you’d like to splurge this is the unit I’d be after.

Car Battery Charger TOPDON T90A, 90Ah Smart Automotive Charger Battery Maintainer&Desulfator with 12/24V Output, 5A-90A Adjustable Charging Current, ECU Programming Stablizer for Boat Mariner Truck https://a.co/d/bepzZnG

At nearly $800, this seems excessive, but I'm willing to entertain

One of functions is for "Battery Repair" does this mean I can restore my old BMW batteries I never turned in for the core charge since I always just bought new batteries from the deal? (I've got 2 BMW batteries sitting in the garage somewhere)

With my Prime card I'll shave an extra 5% off and they have a $50 flat coupon so if it can be used to restore batteries that are basically dead, it would effectively pay for itself. Although, that doesn't look like a standard outlet plug; where would I even power this beast from?

[int_c0m8U$tion]

From my understanding, the repair mode is the similar to most other decent battery chargers like those from NOCO and Ctek.

For coding work, what is needed is a constant voltage between 13.5-14.5 volts for safety. In fact ISTA-P requires the voltage to be within a specific range or it won’t work which is why it’s disabled depending on the connection method.

Here is a good video on the subject.
https://youtu.be/0GSe2y3xYSY

[JB20DGM]

Originally Posted by GnomeChild

Although, that doesn't look like a standard outlet plug; where would I even power this beast from?

The plug on it looks to be a 120v, 20amp plug (NEMA 5-20P)...a bit less common than the usual household 5-15p style. So, it's going to need a 20amp circuit to power it.

[GnomeChild]

Originally Posted by int_c0m8U$tion

From my understanding, the repair mode is the similar to most other decent battery chargers like those from NOCO and Ctek.

For coding work, what is needed is a constant voltage between 13.5-14.5 volts for safety. In fact ISTA-P requires the voltage to be within a specific range or it won’t work which is why it’s disabled depending on the connection method

Well that much I already knew
I'm assuming the T90A would accomplish this? I don't know anything about it but... I am interested

Looks like it might even have USB ports on it; with enough luck I'd even be able to jack my MacBook into it so that it's be charging both car and laptop

Originally Posted by JB20DGM

The plug on it looks to be a 120v, 20amp plug (NEMA 5-20P)...a bit less common than the usual household 5-15p style. So, it's going to need a 20amp circuit to power it.

I don't think we've got any around this house and... I'm no electrician lol
But if it's just a simple swap of the sockets, that much I maybe can manage with a trip to the hardware store :$)

[rbryantaz]

I went with the hp server power supply. My e70 is more thirsty than the e90 and will pull a steady 20amps and often pulls 40 right after keyed on.

I ran had the stabilizer in it for an hour last night while I sorted some things and it kept up fine. It can really only handle 60amps or so at 110v. If I plugged it into 220 then it could do 80amps. Note this type of voltage stabilizer is NOT a battery charger. It can only be used while coding. It supplies a dumb constant voltage and would overcharge the battery if left connected. A battery charger has monitoring to shut off once charged where this does not.



The hard thing is that it takes some soldering skills and a lot of diy to build. For $400 I can build you one... . Hehe I might do it cheaper but really these have to be DIY because they are a lot of work to build well. Someone should start building these and selling them but I don't have the time for it. The info is out there on how to do it.

Someone might build it cheaper. The 14v mod requires the most skill to mod it. Adding the meter makes the wiring very tight and it also needs a good battery cable connector that can handle high amps. Mine is all 4ga and the connection to it uses six 12ga wires from the supply to the outputs to ensure that it can handle the current.

3d printing the plastic ends in ABS was also very slow(and stinky). 8 hours or more for the big one. I would probably do PTEG if doing it again but I wanted the highest temp ABS to keep it in the garage in Phoenix without it melting... You also live somewhere that gets hot so PLA is not an option for 3d printed parts.

[rbryantaz]

It looks like there are now a lot of "Lipo chargers" on AliExpress for $75-100.

They look like basically the same setup as my supply with an adjustable voltage with a box glued to a power supply that also has a meter. The wires look too small and they definitely can't be left connected after coding or they will blow up the battery and could could cause a fire. This is also true of the one I use.

There are various versions.



I think this is probably the same seller on ebay.

https://www.ebay.com/itm/284452582630

Again I would get the 75amp version and the wires may also be a bit small so I would make sure they don't get too hot. I haven't tried one but it seems like it should work. If you can it is better to just build it from a quality hp supply with large wires, etc but this should work if you are always watching it. Seller feedback is questionable of course.

Or there are $300 versions MST80/MST90 that look nicer and are build for it rather than being a modified server supply...

[JB20DGM]

Originally Posted by GnomeChild

I don't think we've got any around this house and... I'm no electrician lol
But if it's just a simple swap of the sockets, that much I maybe can manage with a trip to the hardware store :$)

Unfortunately, it's not a simple outlet swap (technically) as it also requires the correct size of wiring to back it and support the additional current along with a proper sized breaker in the power panel. At least to do it properly and have it function correctly.

[rbryantaz]

Originally Posted by JB20DGM

Unfortunately, it's not a simple outlet swap (technically) as it also requires the correct size of wiring to back it and support the additional current along with a proper sized breaker in the power panel. At least to do it properly and have it function correctly.

A lot of garage (and kitchen) wiring done in the last 30 years uses 12ga wire and 20amp breakers so the circuits aren't overloaded when multiple outlets are used.. Installers still just use the 15amp outlets (probably to not confuse people with the 20amp outlets). A garage will sometimes even just be a single outlet on a 20amp line.

So check the breaker, if it is 20amp and the wiring is the yellow 12ga already then the plug can be changed to the 20amp version.


I bet you have at least one garage outlet (or all of them except for garage door opener outlets) that are 20amp lines Just don't use the other outlets at the same time or it could trip the breaker.


The charger that is for battery repair is probably really the high current for descsling (I think that is the right term) batteries. That is much more current than what is needed for coding.

[GnomeChild]

Everyone's contributed pretty nicely to the discussion here and I was going to go back and add my thoughts/comments but I don't really have the time

Just know that I did end up picking up the T90A that int_c0m8U$tion posted as it seems to be exactly what I'm looking for



Yes, expensive and basically full price, but I think worth it and will pay for itself given enough time. The best part about tools is that over the course of your life they end up paying for themselves in either dollar amounts or time saved

[Tambohamilton]

+1 for server PSU. I have 2 of them wired in parallel that I followed instructions for years ago... Good for 90A, if I remember rightly. Cost an annoying amount when you add in connectors, wires, etc, but still way cheaper than a pukka thing. Only hits 13.6v or something, but that's good enough for what I've done.

Not sure what others are saying here about damaging batteries, etc; you only need a max of 14.5v, and that's what your alternator shoves out blindly for a non-agm battery.

[rbryantaz]

Powermax also has more reasonable priced pmbc units in 55, 75, and 100amp.

55 would be enough for the e series but the 75 is only $30 more at $300 and they seem to have voltage level adjustment.

PowerMax PMBC-75 75 Amp 12V Battery Charger with Clamps https://a.co/d/byjN1B8

The server supply is working really well for me. I probably have $60 into it with the supply, cables, crimp connectors(not counting the hydraulic cable crimper I bought) and meter/shunt. And a bunch of time to change the voltage, 3d print the bezels, etc. I didn't do a dual unit because that takes more work to parallel them and a single is fine for the e-series. I actually made two of them because one unit I got seemed marginal and would sometimes shut down after I made the 14v change. I might have overheated a potentiometer when soldering...

Off the shelf the powermax or the unit gnomechild bought look nice. There is also a Schumacher 100a unit for $666 or some evil price.

[bmwbob89]

This is the one I had a member of another forum make me. Never did have the opportunity to use it. After seeing this thread I thought I should plug it in and see if it works. I just hooked it up to a spare battery in the garage and this is a picture of the screen. Opinions as to if it is doing the correct thing are welcome. Looks like it works to me.

[bmwbob89]

How do I shrink an image so it doesn't look like the above?

[rbryantaz]

Originally Posted by bmwbob89

How do I shrink an image so it doesn't look like the above?

I think they shrink after the final post is made. It looks fine to me unless my phone is resizing it.

It seems to work but you won't really see it without the car pulling current from the battery.

The wire feeding the shunt seems too small for 30amps. Is it 12ga or 10ga?

I would put some shrink wrap over the wire on the far side of the shunt, that bare portion could get hit and short against the grounded case.

[Tambohamilton]

Originally Posted by bmwbob89

This is the one I had a member of another forum make me. Never did have the opportunity to use it. After seeing this thread I thought I should plug it in and see if it works. I just hooked it up to a spare battery in the garage and this is a picture of the screen. Opinions as to if it is doing the correct thing are welcome. Looks like it works to me.

The wire with the yellow crimp on the shunt...that's carrying full current, right? It's too small and will get hot if a decent current is drawn. And you'll see a lot of voltage drop across it, accordingly.

[bmwbob89]

Yes I was concerned about that wire. When I received the unit the end with the yellow crimp on it fell off and I put that one on. That wire is a 12 gauge. I have some wire from an old E46 fuse panel with what looks like 10 gauge going to the 30 amp fuses. I will solder it on the circuit board end and put another crimp another connector on the shunt end. Does anyone know what the car draws key on for programming? I've just used 10amp chargers in the past but the coding I was doing didn't take very long. The one above is showing 40amps. Yikes.

[rbryantaz]

Originally Posted by bmwbob89

Yes I was concerned about that wire. When I received the unit the end with the yellow crimp on it fell off and I put that one on. That wire is a 12 gauge. I have some wire from an old E46 fuse panel with what looks like 10 gauge going to the 30 amp fuses. I will solder it on the circuit board end and put another crimp another connector on the shunt end. Does anyone know what the car draws key on for programming? I've just used 10amp chargers in the past but the coding I was doing didn't take very long. The one above is showing 40amps. Yikes.

The 35.5 amps is a real measurement from my e70 x5 and it was 45 for a minute or so when I first hooked it up... I would run at least three 12ga wires. On mine I just drilled 3 holes through the ground and power blades on the supply. I then went full overkill and ran a wire from each side making 6x what you have...



This is good for 70amps or so without getting hot and probably much more given how short they are. I was a little closer to the positive blade than I liked so I trimmed it a little after the picture so the negative can never turn and contact it.

20 to 30amps is the absolute max for a 12ga wire and it will get very hot at that current. So my 6 is mega overkill but I had the wire and connectors and it fit better in the 4ga crimp lug.

This calculator is handy: https://www.wirebarn.com/Combined-Wi...tor_ep_42.html

So are some wire size charts like this one:

https://www.encorewire.com/products/...ize-table.html