[jporter396]

When it says its advised to use a battery charger take that seriously. a year ago when my battery was new i didnt use one and got away with it. but with a tired battery and 2 days of an inoperable car due to low voltage and unsuccessful flashes it is worth it to at least charge your battery over night to full or use a charger. tried different cables, even after it showed successful flash, car wouldnt operate at all, gauges were messed up, key didnt work, car was messed up. something with low voltage messes up mhd. car is working now but could have been avoided had i used a battery charger during the install the first time.

[gamesfrager]

+1

Not just MHD, any time you are writing code to the car using any method.

[N54Society]

Everyone who has a garage and a BMW should own a charger of some sort. All of those comfort bells and whistles have an energy cost as well. If you don't take long drives, it would even be wise to charge the battery every once in a while.

[TheMidnightNarwhal]

Damn I was about to do a full write after a long drive without a charger since the car cranks so well even as -15c.

How manny amps of a charger should we get.

[N54Society]

Originally Posted by TheMidnightNarwhal

Damn I was about to do a full write after a long drive without a charger since the car cranks so well even as -15c.

How manny amps of a charger should we get.

I have a 3A which is a trickle charge rate, so overnight or long term charging is what it's meant for. I would honestly go higher, like 6A-10A with an auto shutoff.

[nsjames]

I know this one to work:
https://www.amazon.com/STANLEY-BC25B.../dp/B01BYFSUJW

I just used it to winkfp flash my 328 to 330 software.
my brother has used one to do MHD and XHP for the last year.

[hassmaschine]

IMO - it's not really needed, but it's good to have something in case you have problems and your battery goes flat.

Unless you're modifying the boot sector, at worst you'll have a dead battery and have to reflash. People just freak out about it because they don't understand how flashing actually works.

Normally, I don't bother with a charger, especially after the DME is already unlocked - partial writes take like 30 seconds anyway.

I do have one but my E30 is always hooked up to it and I can't be arsed to bother especially since I know nothing bad will actually happen.

[nsjames]

the first MHD flash does take 20-30 minutes.

[Pladi]

Just hook up my other car idling..

[Welcome to NBA Jam]

Thankfully MHD is really good to recover. It's very forgiving for failed flashes. It seems eventually a flash will work correctly with it I've found.

[TheMidnightNarwhal]

Originally Posted by hassmaschine

IMO - it's not really needed, but it's good to have something in case you have problems and your battery goes flat.

Unless you're modifying the boot sector, at worst you'll have a dead battery and have to reflash. People just freak out about it because they don't understand how flashing actually works.

Normally, I don't bother with a charger, especially after the DME is already unlocked - partial writes take like 30 seconds anyway.

I do have one but my E30 is always hooked up to it and I can't be arsed to bother especially since I know nothing bad will actually happen.

Ah see now, this was my main worry.

In my head, if the car ran out of the battery while MHD, depending or where it was at, the car was bricked and you would need to replace a certain module or something woudl be F'ed. But I was also thinking that MHD must have some safeguards in place?



On the subject of having a charger, the AMPS it has is mostly for when the battery will be fully flat and time to charge it?

How much is the drain when I'm coding or running MHD for example. Would a 2A charger suffice?

[Sgop335]

Coding of mhd?

[N54Society]

Originally Posted by Welcome to NBA Jam

Thankfully MHD is really good to recover. It's very forgiving for failed flashes. It seems eventually a flash will work correctly with it I've found.

Yeah, my experience has been that recovery has been excellent with the app. I wouldn't want to get in that state over and over again but it certainly knows what to do when you restart the process.

[TheMidnightNarwhal]

Originally Posted by Sgop335

Coding of mhd?

My bad, type. I meant coding or running MHD flash

[LMB335IS]

Originally Posted by TheMidnightNarwhal

My bad, type. I meant coding or running MHD flash

You can code with the car running if you want to. A charger really isn't needed if it isn't running unless you're going to be at it for a while, or the car already has a compromised battery. Turn off the DRLs, all electronics, interior lights, and you'll be fine. A simple map change (2 min) doesn't require a charger. I do use a large charger (55 amp setting ) when I do initial writes or full writes and most module flashing and/or programming, especially when it's someone else's car where you don't know the history or strength of the battery.

[TheMidnightNarwhal]

Originally Posted by LMB335IS

You can code with the car running if you want to. A charger really isn't needed if it isn't running unless you're going to be at it for a while, or the car already has a compromised battery. Turn off the DRLs, all electronics, interior lights, and you'll be fine. A simple map change (2 min) doesn't require a charger. I do use a large charger (55 amp setting ) when I do initial writes or full writes and most module flashing and/or programming, especially when it's someone else's car where you don't know the history or strength of the battery.

Yeah I closed all electronics to when I was running it without the charger. But like you say it was only for the 2 min write.

I used my friend's charger but now he's not there and I want to activate the MT shift bog fix option but it requires a full re-write.

I still would just want to follow the recommendations and get a charger. It can be useful in the future to .

[Sgop335]

Originally Posted by TheMidnightNarwhal

My bad, type. I meant coding or running MHD flash

I use a 8amp bc for all flashes. My 535i took 38 mins double than the coupe. Works fine but fuel pump is deactivated!

[dpaul]

Originally Posted by TheMidnightNarwhal

How much is the drain when I'm coding or running MHD for example. Would a 2A charger suffice?

With headlights off, fuel pump inactivated by MHD, and power supply set to 13.8V, my 335 initially draws ~23A

[renizer]

i could be wrong here but i think 13.8 is too high of a voltage the LA battery would actually show even with 0 current draw. so there is gonna be a slight charging effect. 23A is no joke tho!

i think some common sense is needed here, as hassmaschine, LMB335is and others have pointed out. long flash - charger, short flash - shut everything you can down and you should probably be fine.

[dpaul]

13.8v is what you want - that's what the alternator will be typically providing when the engine is running

But as you and others have pointed out, you really don't need a supply for map changes or short episodes of programming.

[Cryptikz]

Originally Posted by Welcome to NBA Jam

Thankfully MHD is really good to recover. It's very forgiving for failed flashes. It seems eventually a flash will work correctly with it I've found.

After what? I'm having trouble with my battery not holding a charge and my car is unusable. I want to put a new battery in but I heard it can damage things without registering it first

[Welcome to NBA Jam]

Originally Posted by Cryptikz

After what? I'm having trouble with my battery not holding a charge and my car is unusable. I want to put a new battery in but I heard it can damage things without registering it first

Don't flash or code without a good battery or a dedicated power supply. You can install a new battery without registering it, but it'll have reduced life. You should register a battery after installing it.