inrealtime

I have been getting the "low battery some convenience features disabled" message once a week. I have already replaced the aux battery which was at 10.5v. When I get the message I disconnect all leads to both batteries & the aux is 12.8v & the main is 12.4v. I have been in dyno mode for the last 2 weeks to monitor the voltage & it is always 11.9v before I start then 14.5-15v driving. It has never dropped below 13.7 when started & the 2 times I have received the low battery message I was already looking at the voltage on the instrument panel & it was at around 14v when the message came up.
Any ideas what it could be? It does seem the instrument lights do pulsate slightly. Maby voltage regulator? It seems like the alternator is working fine since the voltage does increase to 14.5-15 when driving

Yacht Master

You need a new main /starter battery voltage should be 13.5.
Sounds like your charging system is operating fine.
If you continue to use your car with a old weak battery you will prematurely
wear out your alternator/voltage regulator.
FWIW on a car so electronically dependent, a low voltage condition is asking for
many other electrical problems, low voltage kills.

inrealtime

Is the 13.5 volts what the dyno mode would read before startup? Not the reading at the battery itself right? I thought the voltage for a fully charged battery is 12.7v?

Mikesamg

Take it in and have the batteries tested, if they are good then it's the voltage regulator or alternator. This is a common problem and I had it as well. Get it fixed before you go down the road and it shuts your brakes off, which has happened recently to a member that I know on here.

inrealtime

It does look like it's the main battery. After I connected the cables I turned on the lights, rear defroster & hazards & then checked the main bat. It dropped to 11.1v, but the Aux stayed constant at 12.8v. When I started the engine the main battery tested at 13.5v. I am going to order one tomorrow.

mtrevelino

Dumb question please. How do you get to dyno mode to see the battery voltage? I got to it one time but have not been able to figure it out again.
Thanks!!!
Mike....

NSX2NV

I need to replace both my batteries too. Where is the best and cheapest place to get them?

izzyz28

Go to Wal-Mart or Autozone. Either one should carry the large starter battery, and I believe most parts stores will have the smaller one(it's a common motorcycle size). I juts bought a brand new starter battery for under $80. If you want OEM then go to the dealer, but in all honesty, a battery is a battery, unless it's something like an Optima.

NSX2NV

Thanks Stupid question but where is the little one located? I know the big one is in the trunk cause I've used it to jump start some people but I've never seen the little one.

inrealtime

To get into the dyno mode make sure the display is on the temp, then turn key 1 click & then quickly press the reset button 3 times. voltage level will come up.

I bought the aux battery which is on the passenger side under the air filter 10mm nut to release, from sears diehard 14 bs $89.

I bought the main battery from autozone for $139.

Everthing working good now. No pulsating headlights or interior lights anymore.

NSX2NV

Thank again!

mtrevelino

Thank you!!

NSX2NV

Does it return to regular after you turn the car off or do you have to switch it off?

inrealtime

When you turn off the engine or you can use the command button of the steering wheel.