AtlasE61TT

So I'm getting a "high battery drain" message when I'm starting the car and I'm pretty sure it the battery that needs to be replaced. The battery is marked with the date from 2011. So right now the e61 535i xdrive has a 90ah 900cca exide battery. If I put a 90ah 720a battery in the car do I have to reprogram the battery or will the car work fine if I juts register it using MHD?

donpb

You still need to register the battery, or else the charge rate will be higher and in turn shorten the battery lifespan.

AtlasE61TT

I've come to understand this through my research, but my question is can i register it with changing having to use carly or pro tools if the battery that I use has the same specs? I saw on MHD app that you can register a new battery but you cant change the specs.

donpb

It's not just the battery specs, when you register a battery, it also resets the mileage which tells the ECU to not charge a new battery so hard.

AtlasE61TT

Okay cool, have you ever done this using MHD?

donpb

Ok, here's the skinny about registering your battery, if you don't...

1. You run the risk of shortening your battery life.
2. You will affect your MPG.

Lots of people don't care about shortening the battery life because their battery will still be under warranty, and they'll simply get a brand-new battery for free. With regards to the MPG, the affect is minimal and so some people don't really care about that either. I register mine; I have a code reader that has the BMS feature. I have not used MHD.

kd7iwp

I see you mentioned MHD, bear in mind that when you flash a tune with MHD it seems to erase your battery registration, it does for me at least. I have always registered my batteries with ISTA but there are plenty of other tools to do it as well. But once I flash with MHD and go back in ISTA it shows no registration date for my battery any longer.

donpb

Well, that's no bueno. I mean, what if your battery is at X mileage, you'd need to set it back to that same mileage or else it'll charge like a new battery. @seanjordan20 Is there some software to input the battery mileage manually?

AtlasE61TT

That interesting I'll have to look into that. I've seen other people saying the same thing in other forums but not to often to be honest.

AtlasE61TT

Update:

Went to advanced got a brand new diehard platinum Agm battery with same exact specs as my previous battery.just used MHD to register the battery for now and everything seems good for now. I guess I'm going to be investing in protool or carly in the near future so this process is a bit easier in the future with these situations.