[Stück]

At 20F ambient temperatures 12.2v is not unreasonable to expect.

Voltage over unloaded terminals is only a small part of the equation though. You need to test the CCA of a "fully charged" battery to make a solid determination of its overall health.

This can be done with the battery in the vehicle with a hand held tester. DO NOT use a old style carbon pile tester unless you want to damage the tester and the battery, a new age solid state tester must be used with AGM batteries.

[Gilgorm]

I have a 2/15/100A charger.
I use 2A if I have time available and the 15A for a quick evening charge (it takes 4 hours after the message appears).
I've never used 100A since it is for an instant charge / start for a car with a dead battery.
My 2012 is on its second battery (low mileage, short city trips, never garaged). Only used the charger three times in 4 years.

Glad OP finally got a full charge.

[jonobro]

Originally Posted by Stück

A 1.25A "charger" us a maintainer, not a charger. It'll likely take days for it to sufficiently charge.

You're going to want a 30/60/90A charger to actually charge the battery in a reasonable time frame.

If you're getting battery discharging messages your battery may be on its way out. Check the production date on the battery, it should be stamped into the negative battery post. 4-5 years is typical max life span.

But be a dumb question but when charging the battery do you charge the one in the trunk or the one under the hood ? Was doing a software update and my car battery died. Charged the one under the hood for hours and still didn't want to turn on so it has to be my trunk battery that went out. No way to recharge it ? And if so how

[Qsilver7]

Originally Posted by jonobro

But be a dumb question but when charging the battery do you charge the one in the trunk or the one under the hood? Was doing a software update and my car battery died. Charged the one under the hood for hours and still didn't want to turn on so it has to be my trunk battery that went out. No way to recharge it ? And if so how

I see an IBS (intelligent battery sensor) attached to your battery in the pic you posted...this means that you should ALWAYS charge from the engine bay jump start teminals. Make sure you are using BOTH correct locations (neg & pos) for hooking up...I've seen many owners select "their own" grounding locations which tuned out not to be actual grounds...then wondered why jumping or charging didn't work.

If you don't know where your engine bay jump start locations are...then turn to your "paperback" owners manual or download a PDF version of one to your favorite device (cell phone/tablet/laptop/desktop CPU).

If you hook directly to the battery to recharge it...then you are bypassing the IBS and this will cause the communication and charging maintinenace by the DME to be incorrect. The IBS (even with the car not running) checks on the battery's voltage...if there is a major change that was not detected by the IBS...then this will be interpreted as being inconsistent...based on the info/data being collected by the IBS.

See warning for charging an AGM battery at this link: https://www.newtis.info/tisv2/a/en/f...nance/1Lil7vLT

{more info from the BMW TIS...take note of text highlighted in yellow and green}

[jonobro]

Originally Posted by Qsilver7

I see an IBS (intelligent battery sensor) attached to your battery in the pic you posted...this means that you should [COLOR="Red"]ALWAYS[/COLOR] charge from the engine bay jump start teminals. Make sure you are using BOTH correct locations (neg & pos) for hooking up...I've seen many owners select "their own" grounding locations which tuned out not to be actual grounds...then wondered why jumping or charging didn't work.

If you don't know where your engine bay jump start locations are...then turn to your "paperback" owners manual or download a PDF version of one to your favorite device (cell phone/tablet/laptop/desktop CPU).

If you hook directly to the battery to recharge it...then you are bypassing the IBS and this will cause the communication and charging maintinenace by the DME to be incorrect. The IBS (even with the car not running) checks on the battery's voltage...if there is a major change that was not detected by the IBS...then this will be interpreted as being inconsistent...based on the info/data being collected by the IBS.

See warning for charging an AGM battery at this link: https://www.newtis.info/tisv2/a/en/f...nance/1Lil7vLT

{more info from the BMW TIS...take note of text highlighted in yellow and green}

Must be trunk battery that's dead

[ezaircon4jc]

Originally Posted by jonobro

Must be trunk battery that's dead

Is there another??

[Surly73]

Originally Posted by Qsilver7

I see an IBS (intelligent battery sensor) attached to your battery in the pic you posted...this means that you should ALWAYS charge from the engine bay jump start teminals.

Yep - Qsilver is right on the money. ALWAYS the hood terminals, never on the battery. (The terminals under the hood connect to the battery in the trunk, but through various monitoring systems that should be monitoring the charging process in order to get things right). Some optioned F10s may have additional batteries, but there is no battery under the hood, only boosting/charging terminals.

[jonobro]

Originally Posted by ezaircon4jc

Is there another??

Yes trunk battery

[HighlandPete]

Originally Posted by ezaircon4jc

Is there another??

Both in trunk.

[ezaircon4jc]

Originally Posted by HighlandPete

Both in trunk.

I don't have active steering on either of our 535's and that area has a cubbyhole where that picture shows that "extra" battery.