I recently acquired a 2025 NX 450h+ and am still trying to educate myself on all the whistles and bells. One of the console buttons activates charging the hybrid battery (traction battery). My question is this: under what circumstances would I need to engage this feature …. especially since this is a plug in hybrid?? Thanks in advance for your responses.

 

Think in terms of Europe, where some cities have "No ICE" zones. If you're traveling from one to another, it's a great feature to have so you can build up enough charge to use in the next city's zone.
There are other good reasons, of course, but that's the best single use I can think of.

 

I have had the same question. It seems like this just trades gasoline consumption for future electrical use. I saw the suggestion provided by mtnman and I suppose that is one plausible use case, but it seems like a weak case for the feature. I wonder if this was intended for use when people cannot find a plug-in to charge the battery - but then why not just run it in standard hybrid (HV) mode?

 

Aside from its normal function, which has limited uses... I find CHG mode useful for forcing the petrol engine to run continuously to give it a proper run sometimes, so that it properly warms up.

 

I pondered this feature for some time until I found I can actually use it. After a longer commute, and exhausting all EV miles, I want a small charge for the next morning to drive to the nearby shared charger or maybe to move the car to load something into the trunk, without starting the ICE. I add a couple EV miles at the end of the trip and i'm good to go.I have no idea if this entered the minds of the designers, but it's helpful for me.

 

Based on your comments, it strikes me that this CHG MODE function would infrequently be used, if ever. Hope it didn't cost me significantly more. In their defense, the auto industry isn't alone in adding functionality to their products which are either unnecessary, or rarely used. BG

 

A spectator's opinion here, but to me one of the advantageous situations for such a feature would be a long drive on the highway after having depleted most of the EV range immediately followed by some distance in heavy city traffic. At highway speeds is when the engine would be operating at near its peak efficiency and is the ideal time to charge the battery, then to be used later in some nasty city driving where the engine would be operating at its least efficient state. Sure, regular hybrid driving at this point would be somewhat better, but being able to go pure EV if heading into extended stop and go this could be one of the ideal situations for this function.

 

Yes, that is exactly the case I normally use it for. I always want some amount of battery range available in case I get caught in a traffic jam with a long stop&go section, or a city with multiple traffic lights I have to negotiate.
I know it isn't necessary, and some feel it is a waste of effort to make the switch, but I really don't think you can deny that it increases the efficiency of the car.

 

Reading these very helpful posts, I wondered whether running the 450h+ plus in CHG mode charge the “+” (EV only) battery?

The comments seem to suggest so but wanted to be clear that I’ve understood. Thank you.

 

Yes, CHG mode uses the gasoline engine to add EV range to the traction battery. If enabled, it will charge the battery up to 80% of capacity.

I have used CHG mode to add EV range to an otherwise depleted traction battery so the remote A/C function has EV range to use. This is really nice on hot days where I want to pre-cool the vehicle before I get into it.

Since I like to add fresh gas every three months, charge mode may also be used to burn off older gasoline prior to refueling.

 

I think there is no extra expense, only a few extra lines of code. They didn't even give that function its own button.

I agree with the posts that refer to having a charge in "city" traffic, however, here in the mountains, we suffer through stop and go traffic in rural areas where traffic to and from the city gets bogged down. Construction, holidays, skiers, tourists, all contribute. When we get stopped, it is so much nicer to be operating in EV mode as you inch along. I expect it in certain areas and can add a few EV miles before I get there. When we're stopped, the AC keeps working, the music still plays, the gas engine isn't operating, and the EV 'miles-to-empty' barely moves.

 

Thanks all for the many responses to my original question on “why the CHG MODE?”. I now believe there are many good reasons for why one might desire this feature. At first I didn’t realize that the CHG MODE would work while driving. However, doing so while on highways makes sense. Maybe not all the time … but still. Anyway, thanks again everyone. Bobby

 

Thank you for your reply. Very helpful and much appreciated.

 

Another use for the CHG mode would be to avoid the start/stop cycles that you experience in Hybrid mode. These start/stop cycles are hard on the engine. i.e. you have generated enough electricity in CHG mode to run in EV mode in the start/stop driving environment or you can use the CHG mode to keep the ICE running to keep the engine warm and oil circulating and to generate more electricity to be able to switch back to EV mode.

Here is a good video by Engineering Explained explaining why hybrids are hard on ICE engines.