12 volt battery monitor

[jeff585]

On the Ioniq5 and EV6 forums I've noticed a number of owners have had their 12 volt batteries fail prematurely.

Someone suggested using a battery monitor similar to what I've attached below as an inexpensive way to provide an early warning that the battery is failing.

I'm thinking that all something like this would do is indicate the 12 volt battery is not fully charged. Also, isn't this just going to tend to run down the charge in the battery especially if the car sits for a few days unused? Or is the 12 volt plug in our cars "switched" so that the power to the plug is turned off when the car is turned off?

Thoughts? TIA.

Amazon.com

 

[CRMS]

In UK, I've fitted a Bluetooth monitor. Like:

Amazon.com

 

[Lexigen]

I have this one installed in my car, after my 12V died with the car sitting in my garage just a week into my ownership. It hasn't happened since. With that I figured out that each time I walked by the car (or anywhere inside the house within range) with passive entry enabled with the phone as key, that it wakes the car and causes quite a bit of draw on the 12V. I've since disabled passive entry. Still, each time you interact with the car, such as opening a door, it will wake the car and draw on the 12V battery. Just 2-3 wake cycles and the 12V will become low, below 12.5V, and *usually* the car will charge it soon after. It typically begins to recharge the 12V at under 12.67V.

Amazon.com

Here are 3 recent screen grabs. That very messy graph on 2/3 at around 11am, I moved the car out to wash. Each of those voltage dips is me opening a door. You can see that after a drive (on 2/6 at 17:13), the battery usually gets low even though while driving the 12V is being charged at around 14.6V.

 

[Bobdhd]

This is my setup. The connections at the top are to connect the battery jump pack. In case of needing to, the jump cables plug in there saving me from having to disassemble the covers on what would surely be the most night of rain in history. It’s Velcroed down & the heavy cables attach to the remaining battery post threads so it’s very quick to remove, should the need arise.