Test Your 12V Battery with This Clever Bluetooth Monitor
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| QUICKLYNKS 12V Bluetooth monitor (Amazon affiliate link) |
The recent 12V Battery Post and associated YouTube video elicited quite a bit of engagement, so thanks for the feedback! The initial analysis indicated that the 12V battery on my Kia Niro EV was potentially marginal. It turns out a single measurement with a multimeter isn't enough to get a true picture of the battery health.
Fellow EV owner and builder Mike Walenga whom I met via the Kalamazoo EV Association recommended a 12V Bluetooth battery monitor which I thought might be helpful for readers of this blog as well. See link below the picture on the left or in the text above.
Note: As an Amazon Associate I earn from qualifying purchases.
Prefer a video version of this? See this Zero E-Michigan YouTube Video.
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| Our friend's Prius' 12V battery was draining due to a dome light left on. |
Data Snapshots
Obviously checking the voltage on your 12V battery with a multimeter only gives you a single snapshot in time. It's important to know whether that snapshot is after the car has been sitting for some time in the cold, right after the car has run and the battery was recharged, whether the battery has loads drawing power and a multitude of other conditions.
Is a parasitic load drawing down your battery? How would you know if you just have a single voltage data point? For example, our friends left their Prius parked with - unbeknownst to them - a dome light left on. That was slowly draining the 12V battery to the point where it no longer started the car.
Trends are Better Than Snapshots
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| A trend can show more detail over time. Click on image to enlarge. |
However, a monitor that shows a trend can give even more insight depending on what else is happening at the same time. Does the voltage drop significantly over time? Is the battery being charged often enough to keep the voltage in the right range?
How Do You Monitor Voltage?
Taking single measurements with a multimeter can get tedious and still won't give you the full picture. A continuous monitor like this QUICKLYNKS 12V Bluetooth battery monitor (Amazon affiliate link) can store trend data over time and then synchronize with your smartphone over time.
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| QUICKLYNKS 12V Bluetooth monitor (Amazon affiliate link) |
In the trend example shown above, the voltage was monitored over several days. During the first few days, the 12V voltage dropped over time because there are a few minor loads like the vehicle's telematics. Then about once a day the DC to DC converter activated thereby recharging the 12V battery from the vehicle's 400V traction battery.
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| A single snapshot may not tell the whole story. |
A few days later I drove the car and there was much more activity associated with running the accessories and the DC to DC converter keeping the 12V battery topped up. You can see those peaks and valleys towards the right side of the trend.
The bottom line for me in this case was that even though the snapshot voltage I measured with my multimeter seemed low, the overall voltage trend shows that the car is keeping the voltage of the 12V battery in a reasonable range.
Long term monitoring can also help determine if the battery is losing charge over time, so I plan to keep an eye on it. That will let me proactively change the battery before it becomes a problem.
That's really the practical application of all of this. Nobody wants to be stranded by a dead battery.
Thanks for reading! I hope you found this helpful.
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