Dear Contributors,

I have a BMW E60 2004, the battery died few months ago and replaced with Bosch S5 100 A battery, the battery charge has been always at 50% (in ISTA battery test), i did all the necessary battery registration, and configuration, i did replace the IBS and the Alternator to test, went through software updates for the whole car, but still the battery would not go up more than 50% in ISTA Battery Charge state

I tested another battery, a used Bosch S3, and the battery charge over 5 days went up to 80%, and I'm really confused, I tried to replace the new S5 battery with another similar one and battery charge remained over 5 days at 50%

I did an extensive test for any power leak, but nothing in this area

Any thoughts? I did a lot of reading on this but no luck so far in getting this resolved

Appreciate the advice

Regards,
Abed

 

After taking the battery out, fully charging the battery, installing the battery on the car, does the charge go down to 50% and stay there?

 

Yep, I tried taking it out and fully charging with a suitable charger, installing back and over 2 weeks monitoring the charge state, it remained at 50%

 

Since I tried another battery and the charge state went up to 80%, I'm guessing the Bosch S5 is not as strong as it should be as I also tested another S5 battery and same result

So maybe the Bosch S5 batteries are not compatible with our cars

Can other confirm?

Thanks
Abed

 

What is the CCA and Ah rating and size (aka group number) of the Bosch S5 battery you used?

 

its 100Ah 830 CCA