AcuraGuy2016

To RLX SH Owners,

How long are your car batteries lasting? Are you able to leave the vehicle at an airport for a week or 2 vacation and it starts OK?

With the SH system, is the ICE essentially starting and stopping multiples times per drive, drawing from the car battery?

Just curious what your experience is with that.

hondamore

The ICE starts and stops primarily using power/torque from the electric motors fed by the Lithium Ion Hybrid battery and not the 12v starter battery.

A lot of starter batteries are being drained down these days because we're not driving as often as usual, so weak batteries are more common than not I would think, not just on cars equipped with an engine off mode.

I would say that a new, fully charged battery in the RLX Sport Hybrid would have no trouble starting after two weeks BUT if the battery is older or has experienced a past that included substantial drain (very common in the Covid world), then the two week layoff with normal parasitic loss might be enough to make starting difficult. I think that having a portable booster fully charged in trunk would probably be a good idea just in case. Better yet, get a friend or family member to drop you off and pick you up or even take an Uber/taxi if you are concerned.

Either way, have fun on your trip (obviously keeping a mask on at all times you are in public, stretching the social distancing to MORE than 6 feet whenever possible, pretty much washing your hands every time you touch anything and constantly reminding yourself and others in your party to not touch your mouth, nose or eyes). Forgive the "old man nagging" - it just spews out of me these days.

mrgold35

I had an issue with both my 19 MDX hybrid and 18 RLX hybrid 12v battery power running down too low after sitting in the garage for +2 weeks. I was getting all kinds of error messages from my Acuralink like CMBS/LKAS error, low oil pressure, electric power steering, charging system error, etc... Both vehicles started with no problems with the error notifications. Took the RLX into Acura and they said it was just from low 12v battery power and a recharge to normal levels fixed it 100%. I now drive both vehicles several times a week for longer trips instead of several times every 1-2 months for shorter trips like before.

I would have a portable battery charger in the trunk if you are going to park your RLX for +10 days. I would even drive the RLX to the airport for +30 minutes before to help top off the 12v battery before parking it for a while.

jdpdata

Our 2017 MDX SH 12V battery died after just 2.5 years. It was replaced under warranty. Due to the pandemic and lack of driving is going to kill a lot more batteries. I plan to hook my cars up to trickle chargers while they sit in the garage

mrgold35

I always figured the EV battery pack might provide some power to the vehicle if it sat for a long time; but, it doesn't. I'm not 100% sure if the starter or electric motor inside the 7DCT re-starts the engine in/out EV mode in normal operation in park or when driving? The hybrid "might" start up "IF" the 12v battery is low and the V-6 also uses the 7DTC electric motor to restart in EV mode?

jdpdata

I couldn't get my MDX to start after leaving the doors ajar for a little while washing it. I guess the cabin light killed whatever juice was left in the 12V battery. Service tech said the 12V battery needs a good charge to start the car, it doesn't rely on the electric motor at all to start. Good thing it died in my drive-way so I was able to get a jump. If we were traveling, we would be screwed. This and the lack for a real spare tire has me really concerned traveling in the boondock with this car.

hondamore

I believe the initial start up of the ICE requires the 12v battery but once all the systems of the car are functioning, the pancake electric motor in the transmission is primarily responsible for the starting of the ICE after it turns off. That is, the 12v battery is required to start the engine with the starter motor and get the computer etc. up and running, but once running, the electric motors can take most of that function. I believe that is why we don't notice a starter motor noise or vibration when the car is starting and stopping during normal driving as long as the ignition is still on the whole time.

That said, it is frustrating to have a "huge" hybrid battery in the trunk and yet still not be able to start the car because of a weak/dead 12v battery. One would think that a "booster link" could be established for that purpose. Alas, I assume that there must be a reliability or safety reason for Acura choosing to not include that function.
Just my two cents