Best way to charge a NX450h+

[Marc Jolly]

Hi all,

I'm coming up to 3 months into ownership of my 450h+ and I've received some amazing figures from it.  First tank of fuel lasted me 2800 miles.  I've noticed recently that the number of miles from a charge has slipped down to 41 from its original 48 when I picked it up.  Whilst I know that some of this may be due to driving style etc I wondered if there is a recommended way to charge the car.  I quite often do small journeys and then immediately recharge the car with maybe only 10-20 miles used.  My question is, is my charging style impacting the range and should I be regularly running down the entire charging range or do the batteries in this car cope well with "top-ups"?  Any experience and advice would be greatly appreciated.  Thanks, Marc

[NemesisUK]

Does the owner's handbook offer any tips or advice? Both my RC and my RX have a small section devoted to getting the best from the car.

[Ken R]

6 hours ago, Marc Jolly said:

Hi all,

I'm coming up to 3 months into ownership of my 450h+ and I've received some amazing figures from it.  First tank of fuel lasted me 2800 miles.  I've noticed recently that the number of miles from a charge has slipped down to 41 from its original 48 when I picked it up.  Whilst I know that some of this may be due to driving style etc I wondered if there is a recommended way to charge the car.  I quite often do small journeys and then immediately recharge the car with maybe only 10-20 miles used.  My question is, is my charging style impacting the range and should I be regularly running down the entire charging range or do the batteries in this car cope well with "top-ups"?  Any experience and advice would be greatly appreciated.  Thanks, Marc

I think that running the Battery down may be better for the batteries. In the last few weeks I have completed a number of longer journeys running thr batteries to nil in pure EV mode. I have now had an indicated 54 miles of EV mode available after the most recent charge.

[Spock66]

1 hour ago, Ken R said:

I think that running the battery down may be better for the batteries. In the last few weeks I have completed a number of longer journeys running thr batteries to nil in pure EV mode.

I think's that a better approach, although the Battery won't be nil (which would damage the battery) but at the minimum permitted charge level.

[ColinBarber]

1 hour ago, Ken R said:

I think that running the battery down may be better for the batteries.

Frequently taking a lithium Battery down below 20% should ideally be avoided (even with a buffer below 0% that you cannot see). In the short term it won't appear to affect things but it will accelerate ageing of the Battery where capacity is lost.

Your 'improved' range is just calibration. The capacity was always there, the Battery management system just was unaware so a full charge to 100% and running down to 10% every few months can be worthwhile.

[NemesisUK]

Reading the handbook the traction Battery is only ever charged to 80% max capacity. Presumably to allow for regenerative braking from the start of a journey?

[RXtoNX]

8 hours ago, Marc Jolly said:

  I quite often do small journeys and then immediately recharge the car with maybe only 10-20 miles used.  My question is, is my charging style impacting the range and should I be regularly running down the entire charging range or do the batteries in this car cope well with "top-ups"?  Any experience and advice would be greatly appreciated.  Thanks, Marc

9 times out of 10 I know what me next trip is so I usually try to calculate if there is likely to be enough range left in the batteries. If there is I don’t top up, and if it falls 5 miles or so short I still don’t top up (I’m old fashioned, I don’t like an engine not being used for too long)

Hence most of my charges are usually around the max 14-15 kWh mark.

29 minutes ago, ColinBarber said:

Frequently taking a lithium battery down below 20% should ideally be avoided (even with a buffer below 0% that you cannot see). In the short term it won't appear to affect things but it will accelerate ageing of the battery where capacity is lost.

Your 'improved' range is just calibration. The capacity was always there, the battery management system just was unaware so a full charge to 100% and running down to 10% every few months can be worthwhile.

I thought that the hybrid system is designed so that the batteries cannot be fully depleted, have I got this wrong?

[ColinBarber]

8 minutes ago, RXtoNX said:

I thought that the hybrid system is designed so that the batteries cannot be fully depleted, have I got this wrong?

If you have it in EV mode it will let the Battery run down, but not fully depleted as that would severely damage the Battery.

[NemesisUK]

9 minutes ago, ColinBarber said:

If you have it in EV mode it will let the battery run down, but not fully depleted as that would severely damage the battery.

And render the car inoperable, as it wouldn't be able to start the ICE

[dts439]

On 9/2/2022 at 6:09 PM, NemesisUK said:

Reading the handbook the traction battery is only ever charged to 80% max capacity. Presumably to allow for regenerative braking from the start of a journey?

This is an interesting question.  My previous A3 etron hybrid would noticeably do no regen charging when charged to 100% (which it always was from start as the range was always so small so I always stuck it on charge after every trip) - it always felt like a lost opportunity.  I'll see if the NX is the same.

[Harrier Man]

On 9/2/2022 at 6:09 PM, NemesisUK said:

Reading the handbook the traction battery is only ever charged to 80% max capacity. Presumably to allow for regenerative braking from the start of a journey?

My reading of the manual (page 42, note 14) is that it is only in hybrid Battery charge mode (ie engine is charging Battery whilst on the move) that the Battery will be charged to 80% of fully charged. If you plug it into a wall socket or fast charger, then my understanding is that it will charge to 100% (or something close to it).

[Gureamu]

Interesting question this one. Lithium Ion batteries are under the least stress when they are 50% charged. At 50% there are roughly equal ions on each side of the membrane. You'll probably notice that when you buy a new phone or Battery device, they come from the factory with 50% charge. The best approach for Battery longevity is to maintain the Battery at or around 50% for as long as possible. If you're going on a road trip, try charging the Battery to full as close to departure as you can (use scheduling). When you arrive with no EV range left and you're not planning a long journey, try charging it back to around 50%. You can't take the NX Battery below about 30% anyway and so cannot run it down to 0%.

[Gureamu]

One question I have around charging is what is happening when the Battery is showing 100%? When I charge the car it continues to charge, albeit at a much slower rate' for around 30 minutes after it has reached  an indicated 100%; the estimated EV range does not increase at all during this time. Does anybody know what's happening with this additional current? 

[Joey020]

On 10/3/2022 at 2:51 PM, Gureamu said:

One question I have around charging is what is happening when the battery is showing 100%? When I charge the car it continues to charge, albeit at a much slower rate' for around 30 minutes after it has reached  an indicated 100%; the estimated EV range does not increase at all during this time. Does anybody know what's happening with this additional current? 

I think it's like a mobile phone. It charges at its fastest rate in the middle 20% to 80% then trickle charges so even though it says 100% it's more like 95% in order to not degrade the Battery as charging to 100% every time is usually bad for batteries. Only guessing.  

[Harrier Man]

I think Joe is on the right lines with his reply. I recently had an update to my Samsung tablet, after which it gave me a message along the lines that in future it would be showing 100% charge even when at 85% in order to preserve Battery life.