[paulalfano67@gmail.com]

Just plugged battery tender into 12v outlet 2022 Z4 m40i. Why does hazard switch remain illuminated during charging.

Well I guess 12v is NOT hot all the time like my Porsche. It shut the the tender off after a while.

[Combatcrew2]

Originally Posted by paulalfano67@gmail.com

Just plugged battery tender into 12v outlet 2022 Z4 m40i. Why does hazard switch remain illuminated during charging.

Well I guess 12v is NOT hot all the time like my Porsche. It shut the the tender off after a while.

You are right, it switches off after 10 minutes

[GerryC]

Originally Posted by paulalfano67@gmail.com

Just plugged battery tender into 12v outlet 2022 Z4 m40i. Why does hazard switch remain illuminated during charging.

Well I guess 12v is NOT hot all the time like my Porsche. It shut the the tender off after a while.

You might try reading the manual.

[Matthewstorm]

When I asked my Salesman which battery tender to use he said 'What's a battery tender?'

[Wynnsiensheng]

Originally Posted by Matthewstorm

When I asked my Salesman which battery tender to use he said 'What's a battery tender?'

It isn’t terminology that I have heard before. Battery charger is standard wording in the UK and Singapore. I’ve also heard the term float chargers used for chargers designed for long term use, just topping up the battery when the charges drops a little, due to the car not being used for a lengthy period.

So I learned something new. Battery tender…..filed away in my Americanisms file. 😁

[StanDiego]

Originally Posted by Wynnsiensheng

It isn’t terminology that I have heard before. Battery charger is standard wording in the UK and Singapore. I’ve also heard the term float chargers used for chargers designed for long term use, just topping up the battery when the charges drops a little, due to the car not being used for a lengthy period.

So I learned something new. Battery tender…..filed away in my Americanisms file. 😁

We sometimes tend to use popular brand names as generic descriptors, Coke for cola, Battery Tender for float chargers, Crescent wrench for adjustable wrench, Vise-Grip for locking pliers, etc.

[Amadeo]

This is the one sold by the dealer without the bmw logo. You can buy it in Amazon.

[Wynnsiensheng]

Originally Posted by Amadeo

This is the one sold by the dealer without the bmw logo. You can buy it in Amazon.

I’ve used this brand of float charger, sorry battery tender, in the past. Worked well for me.

[Matthewstorm]

Originally Posted by Wynnsiensheng

I’ve used this brand of float charger, sorry battery tender, in the past. Worked well for me.

Do you use AGM?

[Wynnsiensheng]

Originally Posted by Matthewstorm

Do you use AGM?

If SGM is another brand of float charger, I haven’t used them. I’ve only used the CTEC one. Mine look exactly like the photo in the thread. Ordered them from Lazada, which is a Thai version of Amazon.

[Christos]

I have a tender that you clip to the + and - terminals, Where do you clip the ground in the engine bay, everything seems to be coated or aluminium

[stlcdr]

Originally Posted by Christos

I have a tender that you clip to the + and - terminals, Where do you clip the ground in the engine bay, everything seems to be coated or aluminium

There's a metal post on the right side of the car (left side looking into the engine bay). Its kind of 'outside' the bay, itself.

[GerryC]

Originally Posted by Christos

I have a tender that you clip to the + and - terminals, Where do you clip the ground in the engine bay, everything seems to be coated or aluminium

Obligatory manual reference: Item 2.

[Christos]

Originally Posted by GerryC

Obligatory manual reference: Item 2.

Thanks, I was too lazy to go into the freezing garage, slither between everything and dig out the manual from the glove box.

[Matthewstorm]

Originally Posted by Wynnsiensheng

If SGM is another brand of float charger, I haven’t used them. I’ve only used the CTEC one. Mine look exactly like the photo in the thread. Ordered them from Lazada, which is a Thai version of Amazon.

AGM is a setting on your battery tender.

[StanDiego]

Originally Posted by Wynnsiensheng

If SGM is another brand of float charger, I haven’t used them. I’ve only used the CTEC one. Mine look exactly like the photo in the thread. Ordered them from Lazada, which is a Thai version of Amazon.

AGM stands for Absorbent Glass Mat, one of several different battery technologies and different from the traditional flooded lead-acid batteries used in vehicles for decades.Your Z4 uses an AGM battery and the charging profile used must be different for them than conventional batteries, thus the AGM setting on your CTEC charger.

"Regular battery charging can break AGM batteries. Regular batteries need 15-17 volts to get the same amps. However, voltage greater than 15 volts can overheat an AGM and generate enough pressure to pop its safety valve. That one-way valve is supposed to relieve excess pressure from the harmless gases that come when a battery’s charging. Too much voltage becomes too much pressure, and pop. Without an airtight seal, an AGM will dry out in hours."

[Wynnsiensheng]

Originally Posted by StanDiego

AGM stands for Absorbent Glass Mat, one of several different battery technologies and different from the traditional flooded lead-acid batteries used in vehicles for decades.Your Z4 uses an AGM battery and the charging profile used must be different for them than conventional batteries, thus the AGM setting on your CTEC charger.

"Regular battery charging can break AGM batteries. Regular batteries need 15-17 volts to get the same amps. However, voltage greater than 15 volts can overheat an AGM and generate enough pressure to pop its safety valve. That one-way valve is supposed to relieve excess pressure from the harmless gases that come when a battery’s charging. Too much voltage becomes too much pressure, and pop. Without an airtight seal, an AGM will dry out in hours."

Very interesting, thanks for that info.

I primarily used the float charger for my 911 because I didn’t use it that much (40k km in 17 years) and a 4 series that got used during certain months of the year, but not in others.

My G29 probably won't do much in the way of mileage, but will get fairly frequent use, except during the rainy season. So shouldn’t need a float charger. But if it does, I know about the AGM thing now. I’ll check with the dealer that the battery spec here is the same as in the USA. Don’t see why it would be different, but you never know.

[Wynnsiensheng]

Originally Posted by Christos

Thanks, I was too lazy to go into the freezing garage, slither between everything and dig out the manual from the glove box.

I usually look at car manuals online. Every car I buy, the manual that comes with car is written in Thai. Can’t understand a word of it 😂

[GerryC]

Originally Posted by Christos

Thanks, I was too lazy to go into the freezing garage, slither between everything and dig out the manual from the glove box.

No problem. You can also access the manual through the MyBMW app or if you log into the My BMW web site, you can download a pdf version to your computer.

[Balr14]

I have a CTek charger I used on my 997.2. I guess it is time to put the Z4 away and put the charger on it. I hate that. I want to drive it!