Well so far it seems that there are no issues! Does any PHEV owner know differently?
But I took the opportunity to measure the state of the high capacity lead acid battery of the PHEV having left the car unused for at least 8 weeks. It was left with the lithium battery in a full charged state and after 8 weeks that still registered as 99% charged. The 12 volt system voltage had however dropped to 12.0 volts and a bit less under load. Immediate conclusion is that the main lithium system will not maintain it when the vehicle is off. A symptom of the reduced 12 volt capacity was that the door mirrors did not automatically unfold however as soon as I pressed the unlock button on the door handle they did.
[I tried plugging in the normal charge lead but because the car refused to trigger the charger to the on state there was no effect on the 12 volt side. I'll check again the next time I need to plug in to find out if, as I suspect, the 12 volt side will be charged while the main batteries are charging].
I can confirm that during plug-in charging of the Lithium battery the 12 volt lead acid battery is also charged. The 12 volt system sees a voltage of 14.9 volts as soon as main charging begins. This does not mean that a completely flat 12 volt battery will have time to fully recharge but i would guess that the 12v charge rate is around 8 to 10 amps so on a six hour cycle it will probably get about 75% charged at worst.
The lead acid battery on this model has a much higher capacity than the HEV 12 volt side so maybe longevity was considered important.
Last edited by roadster on Sun Aug 13, 2023 3:00 pm, edited 1 time in total.
roadster wrote: ↑Wed Jun 14, 2023 10:14 am
Immediate conclusion is that the main lithium system will not maintain it when the vehicle is off.
Sad, but can't disagree with the logic.
A symptom of the reduced 12 volt capacity was that the door mirrors did not automatically unfold however as soon as I pressed the unlock button on the door handle they did.
Switching those off (and the Passive Keyless entry in general) makes sense as a battery-saving strategy, 'cos it probably uses 5W or so at 5 second or so intervals.
The lead acid battery on this model has a much higher capacity than the HEV 12 volt side so maybe longevity was considered important.
Maybe its extra weight isn't considered a big deal in the grand scheme of things? (considering the bulk of the traction battery).
