Will I need a trickle charger over vacation on a 2018?

If you have a battery tender, why not connect it? I put our 2011 Gen3, and our 2016 Toyota Corolla on battery tenders for our 2.5 week trip recently.

For a third car, a 2010 Toyota Camry 3.5L V6, we charged the battery then disconnected the negative battery cable before we left. Came back, reconnected the battery and it started up fine.

SM-G781V ?

 

And if you don’t have a charger, why not get one. A decent quality smart charger.

we drive once or twice a week, and having a charger at the ready COMPLETELY takes off the pressure (gotta drive the car or the battery will die).

any day the cars not being used, on goes the quick-connect cable, using a CTEK 4.3.

 

Unplug the traction battery charger and the car should be OK for 10 days. If you do have a tender, hook it up, then there's no worries. That model is simple to jump start since the battery is under the hood.

Hope this helps....

 

I did not think the traction battery was required to start the ICE.

So even if the traction battery were to drain to zero Start-of-Charge, that has no bearing on the vehicle's ability to start.

 

Huh????

I believe on all Toyota hybrids Mig1 plays double duty as the starter/alternator for them all. Mig1 requires traction battery voltage to spin the ICE and start it. If traction battery SOC is 'actual' zero; I don't believe the car will go into 'ready mode'. If the traction battery is at a "virtual" zero SOC (some unseen reserve left), there might be enough in it to spin the motor once or twice.
Haven't had that happen to me, so I don't know what the car's programmed response would be....

If you would like to test your theory; you can pull the traction battery safety disconnect and try to start the engine. I'm 99% sure it won't go into ready mode; much less start the engine...... but I could be wrong.....

 

To me, starting the car is ready mode, which uses the 12 volt as everyone knows. Yes put it on a smart charger. I have a bunch now thanks to Amazon easy to buy things. The last one was a Schumacher 800ma UL listed, which has nice clamps, to me. It was under $16 before tax.

 

A non-plug-in Prius should go much longer than that, unless the 12V battery is seriously discharged or nearly dead. Mine (Gen3) were left behind for 3+ weeks numerous times, without issue. Was a bit concerned about a 44 day absence, but shut off the smart key system and it was OK. When the batteries were older, I did pre-top-up with a battery tender several times before longer trips, but removed the tender before departing.

I can't speak to the issues specific to the Prime.

 

3 weeks is ok with a like new 12v battery. However a very low capacity 6 year old 12v battery might not last 10 days. That same 12v battery driven daily or every three days might last four more years. A small $35 Battery Tender Jr would be a good option especially if the car is garaged or otherwise protected from rain. They come with a quick connect wiring option so it’s easy to connect or disconnect without digging for the battery.

A can’t miss choice is a lithium jump box such as the Noco GB40 as long as you know how to get into the car with the manual key and then access the jump box without needing to open the powered hatch. That box also allows you to jump conventional cars without risking your Prius electronics.

PS: Multiple Prius vehicles are known as Prii - a name even Toyota has acknowledged.