12V battery low warning light HS PHEV

[mevvi1]

Just received suggested battery from Tayna batteries. They suggest 027 ENDUROLINE CAR BATTERY 60AH. They also stock the same battery for start stop cars! One is wet technology the start stop one is agm. Not sure which I need. Any help would be appreciated.

 

[Mymghs99]

Just recenly replaced battery on my 2021HS PHEV after being stranded . Foolishly i had ignored the warning . needed Tom from the AA who replaced the battery and informed me that in his experience the MG batteries are warranted for 1 year only. we live and learn !

 

[craig busbridge]

Today my PHEV started tooting the horn but at a very sickly volume. Nothing at all worked. It kept intermittently tooting at a more and more feeble effort. I climbed into back and manually (with a screw driver) opened the hatch, measured my battery voltage at about 7 volts. Called MG assist, a guy came and jump started with a hand carried pack. He made a statement, "it seems that the MG's sometimes just need a boost". The dash immediately displayed the normal 14ish Volts. This car is a little scary at times.

 

[Jto]

Today my PHEV started tooting the horn but at a very sickly volume. Nothing at all worked. It kept intermittently tooting at a more and more feeble effort. I climbed into back and manually (with a screw driver) opened the hatch, measured my battery voltage at about 7 volts. Called MG assist, a guy came and jump started with a hand carried pack. He made a statement, "it seems that the MG's sometimes just need a boost". The dash immediately displayed the normal 14ish Volts. This car is a little scary at times.

How long has the car been standing with out use

 

[craig busbridge]

No more than 2 hours, it was actually on a 240V 10A wall socket being charged.

 

[Jto]

Do you do lot of short journeys.

 

[craig busbridge]

I do a 144km drive at least once a week, maybe twice. Rest are < 60km. The battery would be 2yrs old, I suspecting it's faltering, probably a monitoring system draining it 24/7. I also gather that when charging the 380V 16ah battery the 12V battery doesn't get a charge. Go figure.

 

[craig busbridge]

I also note, that the warning toots that warned of a low 12V battery continued until there was insufficient voltage to make the horn work. A self fulfilling prophecy. I think the software engineers could do with a little schooling.

 

[Jto]

Ok that should keep the 12v battery fully charged so your battery may need to be replaced.

 

[craig busbridge]

I think you may well be right. I've been reading a tad, and it seems like people are having difficulty sourcing or even knowing what battery to use.

 

[Jto]

I also note, that the warning toots that warned of a low 12V battery continued until there was insufficient voltage to make the horn work. A self fulfilling prophecy. I think the software engineers could do with a little schooling.

You find most things work this way when there low voltage.

 

[Jto]

I think you may well be right. I've been reading a tad, and it seems like people are having difficulty sourcing or even knowing what battery to use.

Just do a search with suppliers of battery’s

 

[craig busbridge]

You find most things work this way when there low voltage.

Unfortunately you are right.

 

[Jto]

You find most things work this way when there low voltage.

You could get a 12v charger change up the battery and have it tested to see the condition of the battery.

 

[craig busbridge]

I have a 12v charger at home, I'll be there tomorrow after a 144km run. I just hope I don't have to call MG assist to get going in 8 hours time. It seems there is a threshold voltage below which the system will not "boot". Once it boots I think the Traction battery charges the 12V battery.

 

[Jto]

Sit in the car in ready mode for 30 minutes to charge the 12v battery, that will give you a chance of been ok

 

[craig busbridge]

Once the battery gets below a threshold absolutely nothing happens, you could sit there all day.

 

[Jto]

Once the battery gets below a threshold absolutely nothing happens, you could sit there all day.

That way I said be in ready mode if car is too low it will not start.

 

[craig busbridge]

If you can get into ready mode, why wait? Just drive. The battery is charging. The real problem is getting to ready mode.

 

[Jto]

If you can get into ready mode, why wait? Just drive. The battery is charging. The real problem is getting to ready mode.

Did you get into ready mode in the morning.