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Trouble finding battery with proper ledge

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4 hours ago, Jimmy said:

 

I've read about this and my understanding is that the charging system on the newer cars runs more of a charge/discharge routine for a couple reasons.

One being that the alternators are higher-output, and higher-output alternators reportedly charge less at low speeds than lower output alternators. I don't know why that's the case but it seems to be a popular conception.

The other is that they burst-charge more aggressively to take advantage of recovered energy such as while decelerating.

 

This is where the battery registration comes in. It needs to know how much/how quickly it can force energy into the battery so it can operate as effectively as possible in its discharge/charge cycles. If it's trying to fast-charge a battery that can't handle it (including a severely degraded battery that was once registered and functioned properly) it can lead to fire.

 

That's why it's risky to jump start newer BMWs. I'd always heard about it and assumed it was due to incorrectly connecting the jumper cables, but a friend of ours called AAA, the jumper her 5er, and it subsequently burned up a bunch of stuff in the electrical system on the way home. Insurance covered it but it was never right after that and she traded it in.

 

I read all of this and I wonder what problem car manufacturers are trying to solve by doing this. I suppose it’s all to do with that bloody engine stop / start thing that I always turn off. 

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6 minutes ago, Simeon said:

 

I read all of this and I wonder what problem car manufacturers are trying to solve by doing this. I suppose it’s all to do with that bloody engine stop / start thing that I always turn off. 

 

Fuel mileage, it’s all about as little drag from the alternator as necessary.

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Just now, tjones02 said:

 

Fuel mileage, it’s all about as little drag from the alternator as necessary.

 

Gotcha. Though looking at all the other ways modern cars are weighted down, you would think that this would be small beer indeed. 

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6 hours ago, BarrettN said:

Everywhere that I looked I found that my new to me, no battery 74 tii used a group 26r - but the battery tray looked a lot bigger. So is a group 47 the right battery for a 74 tii? 

 

Yes, a group 47 is correct for a ‘74 US Tii. This may not be true for the Euro market square taillight Tii’s, as I do know that the Turbos do have the same smaller tray as the round taillight Tii’s.

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In a sense, yes. It's an efficiency ploy and it gives them control of load on the motor which lets them control/manipulate emissions as well. They squeak a little more fuel economy out of it and tailpipe emissions test cleaner. So they can keep selling V8s and such.

 

I don't mind stop/start in the cars I've driven that do it. I shut my car off when stopped anyway. I often wonder why people are so complacent about leaving their car running for no reason. It seems particularly popular with diesel pickup truck drivers. I surmise it's to ensure that everyone for blocks around knows it's a diesel. 🙄

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The Haltech ECU I have will control alternators.  I have never looked into using the function.

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On 2/8/2019 at 9:56 AM, tjones02 said:

 

While the Group 47 is the preferred replacement for the R56 Minis and regular 2002s and ‘74 Tii’s. And, it may be smaller than the optional factory installed Mini batteries, it is much larger than the standard original Mini batteries, which are the same size as the original 2002tii batteries.

 

And... When you upgraded to an AGM battery in your Mini, did you have the car reprogramed to know that it now has an AGM battery? And or, did you have the new battery registered to the car? These generation Mini, and BMWs, require that whenever a new battery is installed that the car’s computer be told that, so that it’s computer controlled alternator can charge the new battery accordingly. These cars charge an ild battery differently than a new one and can, and will, overcharge a new battery. Especially a new AGM battery that shouldn’t be charged with the 16 Volts that these cars alternators can put out... The car is likely still also programed for a standard lead acid battery and will overcharge that AGM....

 

Our ‘02s old school alternators/voltage regulators don’t usually charge over 15 Volts, so there’s no worry in using AGM batteries there.

I totally missed the OP has a Tii I saw the photos of air cleaner cars in the thread.

Good to know I am on the right track selecting an group 47 for my carb model. I like the thought of AGM since I seem to store cars a bunch and AGMs lose charge a bit more slowly. 

I am lucky (?) to have an early 07 Cooper S with no extra wiring on the negative terminal... i.e. need to program. 

 

 

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