blaser

On my 2018 RLX SH I have a strange phenomenon with the Hybrid battery, the dealer tells me it is normal but I want to verify with the forum.
If I enter the highway with full battery ( I see the gauge almost on full) , driving on the highway with high speed, 60-70 the hybrid battery charge falls to half and stays on the half.
Is this normal?

mrgold35

Same behavior for my RLX and MDX hybrids. The battery level ranges between 1/3 to 2/3 capacity depending on how many hills or how long I regen brake (speeds of 70-80 mph at 5000-72000 feet). I only see my battery packs full on either hybrids on long declines at hwy speeds.

blaser

thanks
I found out that if you activate sports mode the battery will be charged to full

hondamore

blaser, Yes, the hybrid battery function on the highway that you are experiencing is normal.

I too have wondered why the hybrid battery just doesn't stay in the fully charged position (or just below fully charged as it never does seem to reach those final two ticks in the gauge). My suspicion is that overcharging the hybrid battery is harmful to the battery, so when the system senses a steady state of charging with little draw during highway driving, it switches on the electric pancake motor in the transmission and drains the hybrid battery to roughly 50% charge and then keeps it there with constant charging and constant light use of the electric motor(s) which is why the highway fuel economy is slightly better than the PAWS RLX with the same engine. The 50% charge state may also be the most efficient for the hybrid battery to charge and draw at the same time.

Whatever the reasoning behind it, the Sport Hybrid system is ingenious in my opinion and should be featured in every new Acura,

mrgold35

From what I've read about battery tech, the sweet spot for longevity is staying in the 30% to 80% range. Anything below or above that for prolong periods of time can impact the battery life. I only use RLX Sport mode or MDX Sport+ IDS mode if I'm jacking around or driving in mountain switchbacks. I usually let the system deicide the best power delivery between NA and electrical power the rest of the time (RLX normal mode/MDX Sport IDS mode).

DanL07RL

What he said. Also true for your cell phone. Leaving it on the charger overnight, or for long periods in excess of 80%, actually shortens battery life.

mrgold35

Also add in below freezing temps and above 80 degrees can impact your EV+NA mpgs, recharge/discharge rate, and battery life. I've never had much luck with Acura OEM batteries of lasting more that 3 to 3/1/2 years in the southwestern heat. I think EV Li-On battery packs are even more sensitive than the lead acid 12v batteries with temperature extremes. We need one of those battery life meters for our hybrids like they have for iPhones.

blaser

Thanks all