[FoxKhan]

Hi everyone,

I need to buy a new battery for my E91 M47 320D, but not sure what to go for. Can you please help me with some advice?

The battery that I have right now is an original BMW 80AH, 640A (61217604816). I only drive about twice a week, sometimes for short trips, so the battery does not have time to charge a lot. In winter, temperatures usually drop below 0 C. Sometimes they can go as low as -20 -25 C for a few days.

Original alternatives for the 80AH are:

Original BMW AGM-battery 80 AH 61217555719
Original BMW battery (Warranty only) 90 AH 61217604822
Original BMW AGM-battery 90 AH 61216924023
Original BMW AGM-battery 92 AH 61216806755

I have INPA and NCS installed and have used them before. I am thinking of buying an Exide battery, if I understood correctly they are the producer of the original one. Are they good, or should I go for another brand?

Should I go for another 80 AH or for a 90 or 92?

AGM or not, considering my needs?

Would the extra costs for a 90Ah and/or AGM be worth it?

Thank you very much!


Fox

[FoxKhan]

I don't think I will go for an AGM, but for one of the better conventional batteries.

What I am trying to find out: If I buy an 85AH 800A battery (Varta for example), do I need to code it or just register it (will be same type, just a little higher AH)?

What if I buy an 80AH EFB, would that need coding? (And would it be worth it to buy one instead of conventional?)

[lordnikon]

May be invest in a trickle charger if you don't drive that much

[FoxKhan]

Thank you, I have one! (Problem is, I live on a hill and most of the times I have to park quite far from a power source.)

I checked and can code and register a new battery without any problems (I have a friend that has the Carly app, and I already have a cable and other BMW dedicated tools.)

I still have not decided if I should go for a good conventional battery (like the VARTA F18 Silver Dynamic) or an EFB battery. Not sure if the EFB would do better in my case.

[StradaRedlands]

Hi FoxKhan I would recommend staying with AGM, either BMW or Exide. AGM has better build over lead/acid that should last longer, especially in the cold. BMWs are notorious for low voltage problems, so don't skimp with a battery. Look for the CCA (Cold Cranking Amps) rating on them. BMW batteries have excellent reputations for long life and reasonable cost, at least here in The States.

Also look into getting a solar battery tender/maintainer. Just leave it on your dash when the car is parked, and it will keep a trickle charge going to the battery. Buy a good one that won't over-charge or discharge at night.

[FoxKhan]

The car only used original, non-AGM, conventional lead acid BMW batteries. They were all 80AH, 640 A - code 61217604816.

They have been all registered to the car when new.

Now that I figured the coding part (not difficult at all, especially with some apps), I just want to know more about my options.

I understand AGM are the best batteries and already have my eyes set on a Varta and an Exide. Would like to know a bit more about EFB, they seem to have their strong points. For example, if an EFB battery (like the Exide EFB EL800 or the VARTA Blue Dynamic EFB N80) is a better choice for my use than a premium lead acid like the Varta Silver Dinamic F18.

StradaRedlands, thank you very much for the solar charger suggestion, I did not thought about it!