GR86 Low voltage car battery <14v

K

Kilo31

New member
Joined
May 11, 2026
Messages
6
Reaction score
6
Hey, so I just got my car battery changed a few days ago from a wet battery to a dry battery.

I'm noticing that my dashcam tends to enter parking mode whenever I stop at red light and when I check the voltage, is shows that it's sitting significantly lower than my old battery.
My old battery (wet battery) used to sit at 14v even when I idle.

Should I be concerned or is this normal?

(Sorry if I'm putting this post in the wrong thread, I'm not sure where to ask)

IMG_20261020_091252.webp
 
What type is it? (AGM, Lithium etc.)
I have AGMs (although not on the 86) and there's no discernable difference in use.
The voltage you're seeing when the engine is running is the alternator output, rather than the battery voltage as such, and that shouldn't really behave any differently. However, I think the 86 has smart alternator control and will actively vary the charging depending on conditions. So, possibly the different chemistry of the new battery will cause it to behave differently.
Is the battery maintaining charge overnight etc?
 
Anything above 13.8v will be the alternator charging the battery.

The rest voltage for a car battery is >12.6v when fully charged.

1792494933000.webp
 
Off topic but you learn something new every day, wasn’t aware of RAB OFF!
 
After I started using a battery tender I noticed the voltage jumping between 14 volts and 12.5ish volts during driving. It’s the smart alternator doing its job exercising the battery after it’s fully charged, it is nothing to worry about.
 
midlife_sportscar said:
What type is it? (AGM, Lithium etc.)
I have AGMs (although not on the 86) and there's no discernable difference in use.
The voltage you're seeing when the engine is running is the alternator output, rather than the battery voltage as such, and that shouldn't really behave any differently. However, I think the 86 has smart alternator control and will actively vary the charging depending on conditions. So, possibly the different chemistry of the new battery will cause it to behave differently.
Is the battery maintaining charge overnight etc?
Click to expand...
Sorry for the delayed respond, the battery is still brand new and maintains it's charge overnight. The original battery is 55D23R wet battery from factory, my new battery is the 65D26R dry battery from the dealer. I'm not that knowledgeable in the full details in car batteries, so sorry if the information I'm providing is limited or didn't answer your question.

Also, I didn't know the GR86 had a smart alternator. Thank you for the new piece of knowledge.

IMG_20261025_130531.webp


IMG_20261025_130345.webp
 
Evilution said:
Off topic but you learn something new every day, wasn’t aware of RAB OFF!
Click to expand...
Oh yeah, it turns off the Rear Automatic Braking. You can turn it off in the driver assist menu at the gauge cluster menu.

It permanently turns it off even if you turn the car off and on again unlike the PCB (Pre Collision Braking)

IMG_20261025_132918.webp
 
Kilo31 said:
Sorry for the delayed respond, the battery is still brand new and maintains it's charge overnight. The original battery is 55D23R wet battery from factory, my new battery is the 65D26R dry battery from the dealer. I'm not that knowledgeable in the full details in car batteries, so sorry if the information I'm providing is limited or didn't answer your question.

Also, I didn't know the GR86 had a smart alternator. Thank you for the new piece of knowledge.
Click to expand...
OK, I can't say from the pictures what the type/chemistry is.
If your old battery was weak it could be that it never got to the point where the smart alternator would stop charging.
I don't usually have the battery voltage displayed so I've never noticed the behaviour to be honest.
 
midlife_sportscar said:
OK, I can't say from the pictures what the type/chemistry is.
If your old battery was weak it could be that it never got to the point where the smart alternator would stop charging.
I don't usually have the battery voltage displayed so I've never noticed the behaviour to be honest.
Click to expand...
No worries, I still appreciate your help.

My car battery is still perfectly fine, I was just checking to see if the voltage dropping below 14 is normal or not. And by the replies I got it seems that I have nothing to worry about. Thanks again for telling me about the smart alternator thing.
 
You must log in or register to reply here.
Back
Top