[vern321]

I have been doing some research around the need of a stable power supply for coding.

Form what I can tell for an F10 a stable 14.2 v power supply with up to 70 amps is needed to be sure that ECU's don't get "bricked" when coding/flashing. A power supply is different to battery charger as it provides (or should supply) a very stable voltage and a variable current (whilst maintaining the stable voltage) for coding ECU's as the current demand can change.

Also my research indicated that the power supply, like a charger should only ever be connected to the terminals under the bonnet (Hood) and not directly to the battery in the the boot (trunk).

My questions is around timing:
1) when using E-SYS or Bimmercode - it takes a matter of seconds to change a function line in a CAFD and send the change to the car, my understanding is this is simply coding one line in a file that the ECU then reads to change the ECU behaviour or inlock a function.
2) But when an ECU needs "flashing" this can take more time as the underlying code in the ECU is changed, thus a more stable power supply is needed. Indeed my car was in the dealer all day presumably having all the ECU's flashed to the latest version for my car.

I have probably missed some reading somewhere, but I want to add an OE reverse camera so as I understand it this will require the VO to be changed and couple of ECU's to be coded so could take some time thus to be sure I don't break anything I should buy a power supply that is specific for the job, but they are not cheap!

Perhaps I have been lucky when using Bimmercode and E-SYS to date with the "small" coding jobs I have done and not caused any damage by not having a power supply connected when performing the work.

Comments most welcome.

[ezaircon4jc]

I've always used a battery tender. No issues, other than to remember to keep the driver's door closed.

[Unspec]

To clarify:
CAFD coding or VO coding don't need a power supply, since you can keep the engine running for that. The only exception is for DME and TCU codings, but you'll almost never touch those with VO and CAFD codings to begin with

When flashing/programming, yes you'll need a power supply since certain ECU's take hours to flash and you cannot have the engine running. For instance, the headunit is typically the longest one, with HTTP protocol taking 30-60 mins and UDS protocol taking 9+ hours. HTTP is faster, but UDS is dead reliable, so UDS is used as a fall back if HTTP is failing.

I've read that you need 70 amps before, but in my experience a 50 amp max power supply is fine as well. I made one myself from a 750watt decommissioned server power supply. 14.2 is also a bit overkill, anything about 13.5 is fine.

[vern321]

Thanks that explains it!

[Trainwreck914]

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