[clairvoyant]

Where can I order that Intact 45Ah / 450CCA AGM Power Battery?
Any website (preferably in English or French)?
I am linguistically challenged here. Thank You

[GQ335i]

Great writeup! Thanks!

[Aridk]

Interesting find

Unfortunatly I have one of the earlier Batteries with the small green light so if I install this Intact 45Ah / 450CCA AGM Power Battery, will I end up like Scottp999 or is there anyway to code the car to an AGM tech batt.?

And if I go with an old tech bat with 45 Ah it wound´nt be as light and strong

[tscdennab]

Some updates on this battery.

In short, it is an incredible battery, very surprising. Never ever has the car failed to start in any circumstances. I let the car sit for 2-3 weeks multiple times and it started perfectly every time. I let the car sit at 2-3 degrees Celsius for 1-2 weeks and it started every time. And I have iDrive, Comfort Access and OEM alarm.

Drawbacks: the clock resets every time I start the car after more than 3-4 days. Oh, and I get the "battery charge low" message quite often. Also, the Comfort Access system does not work after more than one week or so, you have to use the key buttons to unlock the car. I think I need to get a battery tender to fully charge the battery again, because I don't use the car too often these days and the battery doesn't get a chance to fully charge. First time when I installed the battery in the car I could let the car sit for 2 weeks and the clock didn't even reset. I definitely need to charge the battery. But it never fails to start

I am too lazy to switch the battery to the original battery so I will let it in the car over the winter. I am sure it will not disappoint

[Aridk]

Great with some follow up

Any comments thoughts on my above post?

[tscdennab]

Originally Posted by Aridk

Great with some follow up

Any comments thoughts on my above post?

From my research, you can replace non-AGM with AGM battery (but not the other way around) and see how it works. I think it will work fine. I suppose you can also go to the dealer and code the car for an AGM battery, but I'm not sure if BMW supports this scenario (I read that Mercedes for example has a conversion program for its cars to convert the car from non-AGM to AGM).

You can also try a good gel battery (non-AGM but still non-spillable) and see how it works, like Intact Premium Power 45Ah which weights 12.3kg (even less than the AGM). I think it will work fine.

[BEAR-AvHistory]

Seems like a big waste of effort for a street car.

[tscdennab]

Originally Posted by BEAR-AvHistory

Seems like a big waste of effort for a street car.

You have to realize that there are some people that want to extract every ounce of performance from their BMW, while at the same time keeping it streetable, even if this means some small compromises. For example, if you attend a drag racing event with your mods you will probably end up with a mid-13s quarter mile if you are lucky, while another car just as streetable as yours will be over one second faster. Because of little things like this It really depends of what everyone wants to do with their car. Not everyone is the same, there are different people with different goals.

[JamesM3M5]

NECROPOST! Back from the dead. But OK, I'll bite...

You need weight in the right rear corner of the car to keep the cross-weights proper. A lightweight battery does you no good for a road course. Think about this: assuming 50/50 front-rear distribution, what about Left/Right? Put driver weight in the seat and check: typically 51.0-51.5% left weight. What does that mean? LF and LR tires apply the most force to the ground, while RF and RR apply less force to the ground. This results in uneven tractive forces on the rear tires. I'm no drag racer, but that also means uneven forward thrust resulting in a clockwise yaw moment. Additionally, hooking up requires weight over the drive wheels, too. ET is about traction, MPH is HP:weight.

You want to know what I tell customers who gut the ass end of the car and then complain about the handling? You got it, get rid of the LW battery, drop in a brake rotor and spare tire, and see how the car feels now. Guess where I put ballast in cars that need to make a weight class?

[tscdennab]

Originally Posted by JamesM3M5

NECROPOST! Back from the dead. But OK, I'll bite...

You need weight in the right rear corner of the car to keep the cross-weights proper. A lightweight battery does you no good for a road course. Think about this: assuming 50/50 front-rear distribution, what about Left/Right? Put driver weight in the seat and check: typically 51.0-51.5% left weight. What does that mean? LF and LR tires apply the most force to the ground, while RF and RR apply less force to the ground. This results in uneven tractive forces on the rear tires. I'm no drag racer, but that also means uneven forward thrust resulting in a clockwise yaw moment. Additionally, hooking up requires weight over the drive wheels, too. ET is about traction, MPH is HP:weight.

You want to know what I tell customers who gut the ass end of the car and then complain about the handling? You got it, get rid of the LW battery, drop in a brake rotor and spare tire, and see how the car feels now. Guess where I put ballast in cars that need to make a weight class?

http://lmgtfy.com/?q=car+corner+balancing

[JamesM3M5]

Seriously, smartypants?? I've corner balanced, aligned, and set up more cars than I care to remember. Believe me or don't, but I've learned under the whip of some of the most successful names in BMW and pro racing.

A stock BMW comes in around 50/50 front and rear, 51/49 left and right. That automatically means the right rear ends up light with a proper corner weight. A gutted 3 series is more like 52-53% front, 51% left. This is even worse for the right rear. All those right hand turns leaves the right rear clawing for traction exiting turns. Taking weight out of the right rear only worsens the problem and hurts lap times.

[R1000K3]

Originally Posted by tscdennab

Some updates on this battery.

In short, it is an incredible battery, very surprising. Never ever has the car failed to start in any circumstances. I let the car sit for 2-3 weeks multiple times and it started perfectly every time. I let the car sit at 2-3 degrees Celsius for 1-2 weeks and it started every time. And I have iDrive, Comfort Access and OEM alarm.

Drawbacks: the clock resets every time I start the car after more than 3-4 days. Oh, and I get the "battery charge low" message quite often. Also, the Comfort Access system does not work after more than one week or so, you have to use the key buttons to unlock the car. I think I need to get a battery tender to fully charge the battery again, because I don't use the car too often these days and the battery doesn't get a chance to fully charge. First time when I installed the battery in the car I could let the car sit for 2 weeks and the clock didn't even reset. I definitely need to charge the battery. But it never fails to start

I am too lazy to switch the battery to the original battery so I will let it in the car over the winter. I am sure it will not disappoint

Great information in OP and the other posts you've done in this thread. It seems the selected battery is a bit too weak for the car in general, so I've decided to keep the stock battery after giving your input some thoughts. Good find thought for those that wants to weight reduce the car as much as possible, which can be very rewarding for performance and handling. If I had the Intac battery, I would still use the stock battery during winter to get rid of the annoying effects you describe above. I bet the reason you keep it is because you are interested to see if it will work rather than being lazy.

In opposite to many other cars a tuned 335i works quite well even with one or two passengers. A lot of the performance and handling is then lost but the car is still responsive and can be driven hard without feeling weak or being unstable.

[tscdennab]

Originally Posted by R1000K3

Great information in OP and the other posts you've done in this thread. It seems the selected battery is a bit too weak for the car in general, so I've decided to keep the stock battery after giving your input some thoughts. Good find thought for those that wants to weight reduce the car as much as possible, which can be very rewarding for performance and handling. If I had the Intac battery, I would still use the stock battery during winter to get rid of the annoying effects you describe above. I bet the reason you keep it is because you are interested to see if it will work rather than being lazy.

In opposite to many other cars a tuned 335i works quite well even with one or two passengers. A lot of the performance and handling is then lost but the car is still responsive and can be driven hard without feeling weak or being unstable.

If you drive the car at least once every 3 days I think none of the side effects would appear. But since I have installed the battery I only drove it on week-ends or (most often) every other week-end. I will buy a CTek battery tender and use it monthly on the battery, I think that with this kind of usage there will not be any problems.

[DallasBoosted]

I'll just leave this here.

http://www.voltphreaks.com/products_street.php

[DUI Elite]

Originally Posted by DallasBoosted

I'll just leave this here.

http://www.voltphreaks.com/products_street.php

woooww those are some serious price tags.

[Captain comic]

So I'm resurrecting this thread from the dead lol

I'm looking at Deka ETX-30L 21lbs battery - it's a re-branded Braille that is like a Rolls-Royce in battery world: https://www.amazon.com/East-Penn-Dek.../dp/B004XQME74

It's $112 with free shipping and warranty etc. Not too expensive way to drop 30lbs for track days. I can buy some simple trickle charger to maintain battery when it's not in use

Cold Cranking Amps 400 should start e90 easily no problem. My main concern is reserve capacity (it's 29Ah or roughly 1/3 of OEM battery) - that I won't start at some point due to dead battery and be stranded. I don't listen to radio when car is off, but there are things I can't control: engine fans can keep going for some time when car is shut off. Also, some parasitic draw is pretty much a given in our cars
So those who had lightweight batteries: do you guys think this won't affect ability to start? Can our cars rely to run on alternator for electric needs when on idle or let's say with lights on during night driving? What about WOT acceleration - is alternator power enough to supply high-voltage ignition system and not cause hiccups? I'm just trying to figure out if I can get away with this battery if I'll be careful not to use any accessories when car is turned off

[NoGuru]

Originally Posted by Captain comic

So I'm resurrecting this thread from the dead lol

I'm looking at Deka ETX-30L 21lbs battery - it's a re-branded Braille that is like a Rolls-Royce in battery world: https://www.amazon.com/East-Penn-Dek.../dp/B004XQME74

It's $112 with free shipping and warranty etc. Not too expensive way to drop 30lbs for track days. I can buy some simple trickle charger to maintain battery when it's not in use

Cold Cranking Amps 400 should start e90 easily no problem. My main concern is reserve capacity (it's 29Ah or roughly 1/3 of OEM battery) - that I won't start at some point due to dead battery and be stranded. I don't listen to radio when car is off, but there are things I can't control: engine fans can keep going for some time when car is shut off. Also, some parasitic draw is pretty much a given in our cars
So those who had lightweight batteries: do you guys think this won't affect ability to start? Can our cars rely to run on alternator for electric needs when on idle or let's say with lights on during night driving? What about WOT acceleration - is alternator power enough to supply high-voltage ignition system and not cause hiccups? I'm just trying to figure out if I can get away with this battery if I'll be careful not to use any accessories when car is turned off

Only one way to find out

[feuer]

Originally Posted by Q4P

Yes! This may be an appropriate way of weight reduction for drag racing but not for handling or track driving. It would be best to remove the weight from the front to make the car a little rear heavy but it is impossible to remove almost any weight from the front albeit a crash bar.

Lighter rims, lighter tired, lighter brakes, remove the AC stuff...

[torrque]

Originally Posted by Captain comic

So I'm resurrecting this thread from the dead lol

I'm looking at Deka ETX-30L 21lbs battery - it's a re-branded Braille that is like a Rolls-Royce in battery world: https://www.amazon.com/East-Penn-Dek.../dp/B004XQME74

It's $112 with free shipping and warranty etc. Not too expensive way to drop 30lbs for track days. I can buy some simple trickle charger to maintain battery when it's not in use

Cold Cranking Amps 400 should start e90 easily no problem. My main concern is reserve capacity (it's 29Ah or roughly 1/3 of OEM battery) - that I won't start at some point due to dead battery and be stranded. I don't listen to radio when car is off, but there are things I can't control: engine fans can keep going for some time when car is shut off. Also, some parasitic draw is pretty much a given in our cars
So those who had lightweight batteries: do you guys think this won't affect ability to start? Can our cars rely to run on alternator for electric needs when on idle or let's say with lights on during night driving? What about WOT acceleration - is alternator power enough to supply high-voltage ignition system and not cause hiccups? I'm just trying to figure out if I can get away with this battery if I'll be careful not to use any accessories when car is turned off

The car always relies on alternator for electric needs, and is able to run EVERYTHING on alternator. If that was not the case, you would be dead fish after 1 hour of driving at night, or maybe 10 minutes of driving in winter with seat warmers on....

Problem is, if your car is not a manual, you can't start it without juice, ever. So my answer would be; if it's automatic, forgedaboudid.

[torrque]

Originally Posted by feuer

Lighter rims, lighter tired, lighter brakes, remove the AC stuff...

Yeah, and then add a 40 pounds 7" intercooler.

[ewicky]

Originally Posted by Captain comic

So I'm resurrecting this thread from the dead lol

I'm looking at Deka ETX-30L 21lbs battery - it's a re-branded Braille that is like a Rolls-Royce in battery world: https://www.amazon.com/East-Penn-Dek.../dp/B004XQME74

It's $112 with free shipping and warranty etc. Not too expensive way to drop 30lbs for track days. I can buy some simple trickle charger to maintain battery when it's not in use

Cold Cranking Amps 400 should start e90 easily no problem. My main concern is reserve capacity (it's 29Ah or roughly 1/3 of OEM battery) - that I won't start at some point due to dead battery and be stranded. I don't listen to radio when car is off, but there are things I can't control: engine fans can keep going for some time when car is shut off. Also, some parasitic draw is pretty much a given in our cars
So those who had lightweight batteries: do you guys think this won't affect ability to start? Can our cars rely to run on alternator for electric needs when on idle or let's say with lights on during night driving? What about WOT acceleration - is alternator power enough to supply high-voltage ignition system and not cause hiccups? I'm just trying to figure out if I can get away with this battery if I'll be careful not to use any accessories when car is turned off

Do you have comfort access? I've heard that's the biggest potential parasitic load in our cars.

Another forum member mentioned our alternators can always power everything; that is flat out wrong. Our cars actually have a handy system called load shedding that mitigates issues caused by the fact that alternator doesn't put out it's full current all the time, especially at idle. It measures voltage and other parameters to determine when the alternator is overloaded, and intelligently begins backing off or shutting off the largest non-essential loads, like rear defrost, seat heaters, and HVAC fan. It does this to make sure it's essentially impossible to run the battery flat with the engine running. This is well documented by BMW and posted all over. Normal systems (ignition, fuel, DSC, instruments, etc) + headlights + stock sound system can't pull enough to overload our alternator, though. So you're safe there.

WOT situations should be non-issue; at significant RPMs the alternator is generating plenty of juice for aggressive ignition, fuel, etc.

I think your biggest/only worry is cranking when at least 2 of these are true at the same time:
1. Abnormally great parasitic load
2. Parked for extended periods (>week)
3. Both engine and battery are frigid cold

[torrque]

Originally Posted by ewicky

Do you have comfort access? I've heard that's the biggest potential parasitic load in our cars.

Another forum member mentioned our alternators can always power everything; that is flat out wrong. Our cars actually have a handy system called load shedding that mitigates issues caused by the fact that alternator doesn't put out it's full current all the time, especially at idle. It measures voltage and other parameters to determine when the alternator is overloaded, and intelligently begins backing off or shutting off the largest non-essential loads, like rear defrost, seat heaters, and HVAC fan. It does this to make sure it's essentially impossible to run the battery flat with the engine running. This is well documented by BMW and posted all over. Normal systems (ignition, fuel, DSC, instruments, etc) + headlights + stock sound system can't pull enough to overload our alternator, though. So you're safe there.

WOT situations should be non-issue; at significant RPMs the alternator is generating plenty of juice for aggressive ignition, fuel, etc.

I think your biggest/only worry is cranking when at least 2 of these are true at the same time:
1. Abnormally great parasitic load
2. Parked for extended periods (>week)
3. Both engine and battery are frigid cold

The question was not how the system in the car works. The question was "can the car run without having a fully charged battery at all times, only on alternator?" The answer to that is yes, not only it powers all the systems, it also charges the battery while doing that And you actually answered how it is achieved.