IS it me or the EV mode in a reg pri useless

nearly useless.
but americans demanded it because europe had it on gen 2.

and on a 12 year ild battery, you're not going to get much vs a new(er) battery

and btw, using ev does not save gas. it causes the engine to run more to recharge the battery. and it is not good for the battery to use it regularly.

if you want better mpg's, learn pulse and glide, and keep the rest of the car in top condition.

 

Yeah, on regular Prius, EV mode is just a gimmick. It is used just to get your car out of the garage, but that's about it. If you want to do any duration and speed of EV Mode driving, then you have to have Pip or Prius Prime.

 

It’d be good if it was a little more reliable, say for simple things like moving car from garage to driveway or street.

 

Nobody's mentioned yet that there's a bit of a misconception there. In an ordinary Prius (not a Plug-In or a Prime), even if you could use EV mode more, it wouldn't be expected to save you gas.

All of the energy you can use in EV mode ultimately came from burning gas. If it came from regen braking or coasting downhill, gas was burned getting up to speed or up the hill. Otherwise, gas was burned to spin MG1 and put charge in the battery that way.

But that's an inefficient way to use the energy in your gas, because there's an inefficiency tax when it is put into the battery, and another when it is taken back out. The car is using the gasoline more efficiently when it is just doing its normal thing, and some of the power avoids the electrical detour completely.

It's different if you have a plug-in or Prime, because then in EV mode you might be using energy that got into the car some way other than the filler nozzle.

 

@bisco did in his first res.

 

no worries, i skip my way through most posts

 

The fact that the hv battery exists saves gas and it saves your brakes. It stores energy from various sources and reuses it when its needed allowing a lower horsepower, more efficient gas engine. It allows the engine to shutdown many times per drive while still allowing instant EV power when needed. If the hybrid system battery was bigger you would save more gas. If the hv battery is weak from age, bad cells or corrosion, you get lower mpg, using more gas. There are reports a replacement lithium hv provides more EV range and better mpg.

Living in hill country, I have seen a higher than normal charge on my hv battery due to excessive regen and certain weather conditions. When that happens I can get 30 mph EV mode without coasting and without specifically selecting it. The car is burning off excess charge.

I would suspect Johnny's hv battery is getting weak if 6 mph in EV is the limit. It could also be a side effect of his partial gen4 engine in a gen3 control system.

 

One fella was more disgruntled saying his can’t even go over a mile on ev mode and thought it should go far like a Tesla. And he bought it recently before his post.

 

Hey, I don't think I was fully cognizant it was a hatchback, when I bought. And it took me about 3 years to notice the upper glove box.

 

However if you use my affiliate link for Lithium upgrade: https://projectlithium.com/?ref=9qLPw not only do I make ~$100 but you triple the distance the car can go before it decides to turn the engine on and because this type of Lithium is far more efficient at being recharged compared to Nickel based hybrid batteries, you use less gas to recharge the pack.

 

Triples the distance but doesn't have cell capacity in Ah's listed. Get out of here. lol
Yeah even when new these cars were lucky to get a mile in EV mode. Main purpose here is definitely for pulse and glide purposes and keeping the engine off at stops.

 

It was another fella that I was referring to

 

NiMH battery technology was perfected in the 1990's... This particular type of Lithium was perfected in the 2010s... I helped do winter season testing of a final prototype of this pack starting in Oct. 2020 and it's run perfectly ever since with no drop off in performance: Dr. Prius Packs Less Than A Year Away? | PriusChat

Drives like a totally different car over mountain passes when it gets down to three bars because it still has plenty of power. And for same reason EV mode no longer drops down to 2 bars of power left after a mile or so, but even after several miles I'm still at 3 bars. But yes, EV mode isn't something you're gonna use very often in a Prius. It's mostly just for entertainment purposes.

And to your point of capacity, the pack is designed to match the power curve the OEM battery ECU expects, so it's same in that respect, but way more advanced in efficiency of charge and discharge.

 

Does anyone know how efficiently the Prius transfers energy from the ICE to the battery and then from the battery back to the powertrain?


It only takes about 100-200 Watts to keep rolling at 5mph, but the Prius engine is designed to operate most efficiently between 10,000 and 30,000 Watts:




150 Watts isn't even mapped, but from this chart we know it'll be over 310 g/kWh:


310/220 is 1.41 -- that's at least a 41% loss of efficiency. If you charged the battery at the optimal ICE efficiency and transferred at least 80% of the energy to the battery, and then recovered 80% of the energy back to the powertrain, you'd already be ahead (80% + 80% efficiency being 64% efficient, not 60%)

 

Found this that says the "round-trip efficiency of batteries ranges between 70% for nickel/metal hydride and more than 90% for lithium-ion batteries."

https://ocw.mit.edu/courses/mechanical-engineering/2-60j-fundamentals-of-advanced-energy-conversion-spring-2020/lecture-notes/MIT2_60s20_lec11.pdf

 

I had understood that it takes around 400 watts of various overhead just to keep all the computers and controllers and other essential systems awake, separate from the actual propulsion power needs.

 

This is an excellent explanation of why a hybrid car is most efficient with pulse and glide driving technique. As in a gas engine at is most efficient at 2/3rd throttle similar to 3500rpm. So you use that power to get up to speed (pulse) than use small amounts of electricity to maintain that speed (glide).