Long cranks on start up

[robbieredknapped]

Hi guys, I recently did a DIY on a battery charge in my E87 and a friends E90. So battery wasn't registered after install

Problem is, after the battery change I would regularly have long cranks to start the car, which is abit worrying, where as my friends car had no issues.

Wondering if its the battery issue cos the car was fine before the battery change.

Thanks

[lastMleft]

I thought a new battery needs to be coded at a dealership?

[robbieredknapped]

Originally Posted by Rukuss

I thought a new battery needs to be coded at a dealership?

Suppose to, but I know a few that haven't and had no issues. The E90 use the same battery and had no issues.

[Dackelone]

Originally Posted by robbieredknapped

Suppose to, but I know a few that haven't and had no issues. The E90 use the same battery and had no issues.

Did you replace the battery with the SAME size Amp/Ah rating and cold cranking amps? Is the new battery also a AGM battery like the OE BMW one that came with the car?

IF the the answer is all YES's then you can replace the battery and not need to register it. BUT if the battery has more or less Ah or CCamps... then you will need to register it. You also need to use a AGM battery.

You might also want to check the battery terminals that they are tight and not loose.

[robbieredknapped]

Actually it's not the exact Ah/amp I think it is a little higher then the OEM that it replaces. The connection is fine not loose. Might have to get it coded to fix the problem

Thank you

[Superdaws]

Dackel is right, if its the same spec battery as the original one it doesnt need to be re-registered, but you should still have the battery coding reset as a new battery.

Theres 2 parts to "coding" a battery. Registering the correct battery (ie AGM + amp hours + cold crank rating etc) and then on top of that, coding the new battery which tells the recharge system that a new battery is installed, it then reconfigures the charging profiles to a new (and not old) battery.

[JinAM]

Your long crank is most likely not cause by changing the battery. If it's starting, it's not going to be a loss connection.

Depends on the equipment level, registering the new battery may or may not be that critical as the car might not have an idea of the charge level anyway.

If you are upgrading the battery, ie, high Amperage, AGM etc, then you have to code the upgraded battery type into the car, so it knows how to charge it.

[JinAM]

Originally Posted by Dackelone

Did you replace the battery with the SAME size Amp/Ah rating and cold cranking amps? Is the new battery also a AGM battery like the OE BMW one that came with the car?

IF the the answer is all YES's then you can replace the battery and not need to register it. BUT if the battery has more or less Ah or CCamps... then you will need to register it. You also need to use a AGM battery.

You might also want to check the battery terminals that they are tight and not loose.

It's very unlikely that a E87 or a E90 to come with AGM battery from factory.

If it did came with an AGM battery, then means it's got very high equipment level, and that means even if you replace the battery with the same type, you need to register it so the car knows the charge level of the battery. And so that it will not throw a battery warning unnecessarily.

[robbieredknapped]

Thanks guys, will get it registered and see how it goes