Flat Battery

Faults and Technical chat for the Kia Niro
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Joined: Thu Jun 08, 2017 3:07 pm

Post by PhilB » Wed Aug 23, 2017 11:53 am

I think that the engine starts when you first start out so that it gets up to temperature. At least it seems that way from my observations.

My flat 12v battery problem seems to have gone away (touch wood). I have now done 14500 miles, so 3500 since the last flat battery. Don't think the dealer did anything to cure the problem, just disconnected the battery, presumably to measure the current. (The radio and satnav had both reset - that's how I know.)
The dealer never got back with any news from KIA technical - but then I didn't expect much.


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Post by h2onorth » Mon Aug 28, 2017 8:19 am

Hi PhilB. Can we have update on your flat battery situation. ?
Regs h2onorth

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Post by PhilB » Tue Sep 05, 2017 5:30 pm

Nothing to report. No more incidents. 15000 miles now, and I've had the car 11 months.
No word from the dealer, but I haven't been back to them so I guess they've just forgotten about it.

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Joined: Wed Oct 18, 2017 11:47 am

Post by clivec » Thu Oct 19, 2017 11:43 am

This has happened to me FOUR times in the last month. They have now concluded that it was (like two other cases on the forum) due to a faulty fuel pump not switching off. The amount of time and trouble it has taken to get this far is ridiculous. I hope they have finally found and corrected the correct problem??!!

The first two occasions were on the same day. KIA assist (RAC) concluded it was due to a dead cell in the battery. Took it into the KIA dealers who kept it for 24 hours and insisted the battery was fine (suggestions I must have failed to close the boot!!) or similar!!)

The third occasion was when we were away for a few days. This time KIA assist (RAC) concluded the boot light hadn't been switching off. We had already noticed that the boot needed a 'firm closure so were not convinced.

Booked car in for a check a week after our return and it failed again that morning at home. Thankfully the dealership sent out a couple of chaps who plugged in a terminal and confirmed the battery was 'faulty/dead'. They reported back to the dealership. I was then told I had to call out KIA assist (RAC) and get my car into the dealership. They agreed there was a battery fault but there was then a wait of 24 hours for a new one. In the meantime their checks indicated the faulty fuel pump - as I had mentioned to them the previous day courtesy of reading this forum.

So they have changed the fuel pump as that is what their checks show is broken. The new battery has been kept in stock.

If it happens again................................................................

One RAC man indicated that he had been called out to a NIro which had a flat battery where the boot had been left open whilst it was being packed to move house. Why doesn't the light switch off after a period?.


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Post by VinnyJo11 » Thu Apr 18, 2019 6:53 am

This has happened to me twice now. I've only had the car 2 months and done 2500 miles. First time called RAC out and he couldn't find a problem and jump started car and all was fine until today. I've left the car for 2 days and not used it and it's flat again. The dealer checked it over last month and didn't find anything so am going to jump it and take it back today. I will point out the fuel pump fault I've read about here and see what happens. This is totally unexceptible from a brand new car and am considering giving it back and cancelling my PCP deal....if I can. 🙄

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Post by davethetech » Fri Jul 19, 2019 8:57 pm

there is issues arising from rear door lock catches causing a battery drain and your dealer should carry out a dark current check and follow the workshop manual to confirm the drain. as for the 12v battery charging that is the function of the DC DC converter As soon as the vehicle is EV ready the battery is being charged no need for the engine to be running

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Post by jerrytaff » Fri Jul 26, 2019 12:51 am

earlier in the thread there was a suggestion that the lithium ion battery cannot charge the 12V battery. as davethetech states, there is a dc to dc converter to do just that. The PHEV has an aux battery saver function which automatically recharges the 12v battery from the main battery when the ignition is off and the doors etc are closed. Presumably the lithium battery in the HEV doesn't have sufficient capacity to do the same.
2018 PHEV 3 in Gravity Blue :D
Previous DS (formerly Citroen) DS5 Prestige BlueHDi S/S Auto 2.0, Jaguar X type 2.0 S Diesel

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Post by h2onorth » Thu Aug 08, 2019 1:36 pm

Hi all. Ok so the hybrid cannot charge the 12volt unless the engine is running, possibly and yes most mornings the engine runs for a couple of mins before 'switchingoff'. This time is based on me loading car o/s rather than in garage if lots to load sometimes.
Not sure a few mins like this would make much difference to a 'low' charge on 12volt battery, what say you? We know the hybrid will use engine fairly often in a typical journey but is this enough to keep the 12 volt battery charged? If a night journey, for example, needs full lighting and other accessories, does the 12volt battery rely on the engine to run to keep condition? Cannot the ev battery help at all? On several occasions I have left interior light on or boot not shut properly and the electronics has always turned them off , approx 20 mins later!
I have never suffered a flat battery over this.
I don't think a morning start is designed to help warm the engine much and certainly later in the day the car drives off in 'ev' mode after many hours stationary and suddenly the poor engine had to kick in to assist acceleration, so much for a warm start.

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Post by SnowCanada416 » Tue Dec 10, 2019 9:30 pm

It has happened to me twice. I have the 2018 Hybrid and experienced the same. Doors locked, everything off but battery absolutely flat. the first time I put it on a trickle charger and took my wife's car. the second time I had a booster pack and it was quickly resolved. If there's a known issue I would have expected the dealer to take some action on this during regular service visits.

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Post by MattyJWard » Mon Mar 02, 2020 12:38 pm

Hi all. Well this all makes for interesting reading whilst I sit and wait for roadside recovery for what is clearly a flat 12V. Having driven the car a couple of miles this morning I went for a swim. On returning to the car and trying to start it the ‘check brakes’ warning light came on and the car wouldn’t start in any mode. As I was speaking to the dealership it then cut out completely. No dash lights. Not able to lock etc. so clearly dead. The brake warning could possibly just be the confused mumbling of a dying battery. The dealership were puzzled as to why the battery should be flat (2 yrs and 32k). I will take it in for a thorough check to find where the drain is and will mention the experiences of others posted here. Deeply frustrating as it’s a PHEV and has 33 miles of charge. Couldn’t there have been an emergency switch so in the case of a flat 12v the lithium battery could start the engine?? I’m no tech-head but seems a good idea?!
Kia Niro PHEV Nov ‘17 Gravity Blue

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