Issues starting to creep up.....

My 2015 V is starting to have some strange issues creeping in. First off it started as follows;
1 When coasting down a long stretch of a highway hill, ICE is off and I'm gaining speed and all of a sudden the ICE would kick on for a second and switch back off! It does it once in awhile and not all the time.
2 After I start the cold(or sitting for awhile)vehicle and start my journey on the highway and slowly accelerate to speed, I would get a sudden acceleration(like giving more gas) without any difference of gas pedal movement! Usually happens around 40km/h or so. I live next to a highway if you're wondering with a slight incline in the beginning.
3 I'm starting to have a Key Battery Low Voltage Message and voltage is at 12.3V. I went to try it to see if the hybrid system is charging it but the Key Battery Low Voltage came on for the first time at start,
With these issues happening, the question is it all related to a Key Battery Low Voltage state?
I'm trickling a charge with my Ctek 3300 Charger as we speak.
Starting a search for a replacement battery, I like the BOSCH S6535B or go back to OEM which only lasted 6-7 yrs!

 

That sounds like good news, I've got spare batteries in the glove compartment just for that situation. Crossing my fingers for the easy outcome, Thank you!

 

Finished the trickle charge and replaced my key fob battery. The vehicle started at first attempt and the hybrid system is sending 14.7V to the smaller trunk battery. Tomorrow morning will be a more of a normal start situation and anxious to find out

 

No problems this morning on startup and the lengthy hwy excursion

 

Checked the voltage on the trunk battery, 12.2V
I got a feeling it's on its way out.
What are your thoughts?

 

Long highway drive yesterday and checked battery early afternoon. No heavy electrical load during the drive. Haven't started the vehicle today.

 

About 12C (54F) for drive and 6C (44F) battery test on battery.

 

I'm thinking alike, the search is on

 

My 2004 Sienna battery(Delco) lasted 14 yrs
Pricier AGM's not so much

 

Dealer wants 340 plus tax or 240 for a 4/21 Optima Yellow(6 months)!
Decision, decision......

 

Oh forgot, made a service appointment for the software update as it was pointed out to me. Safety recall RA7
Other warranty enhancements W48 and W51 was brought to my attention.