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Discussion Starter · #1 ·
Does anybody know how regularly the 12V battery should be charged? A few times recently I've noticed a single light flashing on the dashboard when I've looked outside at night, and today on two separate occasions I've parked the car up and been sat in it for a while (with the car turned off) and there's been a small 'clunk' and the light has started flashing. Is this normal?

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Kia E Niro 4
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It is the car carrying out a maintenance top up to the 12v from the traction battery
 

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Kia E Niro 4
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I've only noticed it a couple of times, bt then I can't spare the time to watch the car to see when it happens. I guess it depends on your charging regime and also car usage pattern. I give my battery a top up with my old battery charger every so often.
 

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Soul EV 2020
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This happens something like every 21 or 23 hours - can't remember which - next time you see it note the time and check 21hrs later!
 

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It runs every 24hours for 20mins I think - so next day start will be 20mins later so it slowly moves forward


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Discussion Starter · #8 ·
It runs every 24hours for 20mins I think - so next day start will be 20mins later so it slowly moves forward
The thing that confused / concerned me yesterday was that I saw it once at about 1:30pm, and then again at about 8:30pm, both in the same day. Previously I've only seen it late at night.
 

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E-Niro 64kWh '4' since 9/20 (was Prius)
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Whatever the manual may state (it’s often quite wrong IMO) On the 2020 model UK '4' it comes on once every 24h if left unused. Regular as clockwork. It maintenance charges the 12V at a constant 14.7V for exactly 20 minutes. Irrespective of the 12V battery SOC.

I think the 4+ and the FE were probably the same? However, the 2 LR is a brand new model so it may possibly be different in respect of this feature. If you say you saw the green light twice in one day, that suggests it really is very different indeed.

I read quite some time ago that the Hyundai Kona came on to maintain the 12V at regular 4h intervals! So just maybe this regime has been carried across to the latest Eniros?

If you really want to see exactly what’s going on, get a BM2 Bluetooth battery monitor/data logger and leave it permanently connected across the battery terminals.

(@jwfrosty I'm assuming the car in question is a 2LR?)

Peter.
 

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Kia e-Niro 4 MY20, Zoe Z.E.50 GT Line
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My, probably incorrect, understanding is it runs every 24 hours or if the battery voltage drops. Whether it's smart enough to run if the 12v battery requires it I'm not sure, but if that is the case it may indicate the battery is unhappy. It might be worth considering a battery monitor that will tell you if the voltage is tailing off, sure sign the battery is bad and needs replacing.
 

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Hyundai Ioniq 28
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I seem to remember a forum member saying that there was also an extra programme that ran the battery maintenance sequence if it detected an unusually low voltage in the 12v DC battery. And that if that kicked in numerous times within a short period then it stopped doing that to protect the traction battery from being also discharged as it assumed that there was a more serious problem to be investigated.

Just another factor to bear in mind if the light is seen flashing many times in the same day. In my Ioniq, if the system had kicked in overnight a message was displayed to that effect on the dashboard when next starting the car.
 
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