Being locked out/needing use of key & reset button.

[Deleted User 1326]

A brief look at previous threads informed me that a few owners have had problems gaining entry to the HEV when the small battery’s charge runs low.

Although I don’t like adding another thread to existing threads on a subject that seems to have drawn no firm, authoritative conclusions, I would like to record my recent experience of gaining entry after a period of non-use. My story isn’t enlightening in any way but it may help to alleviate fears in those who dread being locked out of their HEV because of battery drain.

I left my 2023 HEV model at Stansted L/T car park while I went home for 16 days. I fully expected that on my return, I’d need to utilise the ‘secret’ keyhole to gain entry then use the battery reset button to start the vehicle. The matter was in my mind before I parked up after reading several posts in these pages from owners who have experienced such a difficulty after relatively short periods of non-use. In an effort to perhaps avoid the problem, I determined that I would switch off the dashcam completely so that no parking mode occurrences would deplete the little battery. Needless to say, after negotiating the car centrally between the lane lines in the hope that the car wouldn’t receive damage from cars either side in my absence, then unloading luggage, I forgot about the camera!

On my return, it was something of a relief, therefore, to hear the click as I pressed the button on the door handle and the car was up and running as normal without further ado.

Ok, it isn’t at all scientific and hardly surprising, given that the weather has been fine and the battery was probably in a good state of charge when I parked up. In the midst of a hard winter, that might be a different story but I’ll cross that bridge when I come to it.

I had use of a brand-new Seat Arona auto while I was away and while it is a perfectly competent, modern (though juicy!) hatchback, I didn’t really enjoy driving it and the Tucson seemed like a whole different class, which it is, when I re-acquainted myself with it on my journey home.

[Southern Lad]

Mine is currently at the airport while I'm away. Before I park up I always drive it in sports mode which boosts the battery charge on the HEV to almost full, unlike eco which does not fully charge it. This works for me and I have never had any issue leaving it unused for longer periods of time.

[mah006]

Mine is currently at the airport while I'm away. Before I park up I always drive it in sports mode which boosts the battery charge on the HEV to almost full, unlike eco which does not fully charge it. This works for me and I have never had any issue leaving it unused for longer periods of time.

Snap that's what i done when i went to Cyprus for 17 days last month
No problems either

[Southern Lad]

Mine is currently at the airport while I'm away. Before I park up I always drive it in sports mode which boosts the battery charge on the HEV to almost full, unlike eco which does not fully charge it. This works for me and I have never had any issue leaving it unused for longer periods of time.

Snap that's what i done when i went to Cyprus for 17 days last month
No problems either

Great minds & all that.....

[ExTyke]

I've had this problem recently but the PHEV doesn't have the reset button so had to get the AA out. The car has been in for a diagnostic check and they haven't found any issues so I fear it will happen again. What I have learnt is that I can get an early warning of the issue by sending Bluelink messages to the car (e.g navigation instructions). If I get confirmation I know the battery isn't dead.

I'll give the sport mode a go next time as well (thanks for that) and hope it helps.

[PhilHornby]

Mine is currently at the airport while I'm away. Before I park up I always drive it in sports mode which boosts the battery charge on the HEV to almost full, unlike eco which does not fully charge it. This works for me and I have never had any issue leaving it unused for longer periods of time.

Snap that's what i done when i went to Cyprus for 17 days last month
No problems either

Yet there's no evidence of this mechanism at play, if you deliberately discharge the 12V battery. It's called "AUX. BATTERY SAVER+" and apparently was present on the PHEV, but is no more. (Perhaps it's no longer configurable and runs on a timed basis, rather than in response to the state of the battery?...)

Did you notice that the Traction Battery level had depleted by a significant amount when you returned
(Which you might expect, if it were periodically charging the 12V battery).

(I agree that "SPORT" mode tends to charge the Traction Battery to a high level (if you're not making use of it for a performance gain)).

I've had this problem recently but the PHEV doesn't have the reset button so had to get the AA out.

Are you saying this button isn't present on your car

That picture is from the Canadian MY22 PHEV manual. (The only PHEV PDF manual I have access to )

Have you see any signs of "Auxiliary Battery Saver+" in the menu

I can see the logic of taking away the manual 'reset' switch on, if the car has "Aux. Batt. Saver+", but it seems weird to have taken that away as well.

There's a confused/confusing thread on the US Tucson forum on this topic. Contributions went on for 12 months, but no conclusions were reached

[ExTyke]

Yep. There's no reset button. The dealer didn't believe me when I told him and had me FaceTime him so he could look at the switches. This cluster has the fuel flap opener, the tailgate, traction control, but definitely no reset switch. I remember reading about Aux Batt Saver in a US manual but it isn't in mine and I haven't found it in the settings. Not a good state of affairs!

[mah006]

Mine is currently at the airport while I'm away. Before I park up I always drive it in sports mode which boosts the battery charge on the HEV to almost full, unlike eco which does not fully charge it. This works for me and I have never had any issue leaving it unused for longer periods of time.

Snap that's what i done when i went to Cyprus for 17 days last month
No problems either

Did you notice that the Traction Battery level had depleted by a significant amount when you returned
(Which you might expect, if it were periodically charging the 12V battery).

(I agree that "SPORT" mode tends to charge the Traction Battery to a high level (if you're not making use of it for a performance gain)).

When i returned to my car after 17 days the traction battery had reduced from full to just over 3/4 so i would imagine it helped keep the 12V topped up

[andrewsmith]

Mine is currently at the airport while I'm away. Before I park up I always drive it in sports mode which boosts the battery charge on the HEV to almost full, unlike eco which does not fully charge it. This works for me and I have never had any issue leaving it unused for longer periods of time.

I managed to charge mine to 3/4 full in sports mode. 90 days later it started and showed just under 1/4 full. Very impressive. I don't recommend leaving any car for that long but it's good to know as I used to have a car that couldn't be left much more than a fortnight.

[PhilHornby]

When i returned to my car after 17 days the traction battery had reduced from full to just over 3/4 so i would imagine it helped keep the 12V topped up

I managed to charge mine to 3/4 full in sports mode. 90 days later it started and showed just under 1/4 full. Very impressive.

Which car is that, a HEV or a PHEV?

There does indeed seem to be evidence that the Traction Battery is being used to top-up the 12V battery. But I wonder why it's not deployed more responsively? (so you could leave the parking lights on for more than 2½ hours, for example). Some early incarnations of Aux Battery Saver+ gave an indication when they had activated. It also limited itself to 20ish activations. Who knows what algorithm is being implemented now

In March when I picked up the car, the dealer stressed that it should be driven "at least twice a week", to avoid the 12V battery going flat - clearly they've not been informed of any of this .