Prius 75-91mpg

[Nathan jones]

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[Nathan jones]

Production offsets changing bolts to making cf parts are about the same, bolts are quicker but don't lose as much.

Even though I've been able to get 6061/M8/16mm for 41p (quite a record) making just a dashboard or single non monocoque chassis part can win a whole cars worth of bolt difference. As far as the M6 go. I figure you need around 200. Remember grade 2 titanium at least don't conduct

[Nathan jones]

It's not much lighter but wanted to make it super strong, carbon with glass in between

Chassis tie. I will make a front one, it's not supposed to have one but it could do with it. At the bottom of the last picture you can see an exhaust leg now not needed, I will use those

[mohammad]

If you dont mind me asking instead of just focusing on increasing fuel economy have you also considered externally charging the battery and/or increasing battery capacity to further reduce your reliance on fossil fuels?

[Nathan jones]

Like a PHEV, unfortunately for me that would increase mass and use more net energy not to mention hideous electricity costs in the UK. Fuels like petrol (E5) contain alot of concentrated energy and in my opinion is still the cheapest option. A hybrid like mine only uses a NiMH as a transducer not as an energy source. Hydrogen would be the only other vehicle I would personally consider. but there are political reasons it's not yet available, you would need to ask around why. I still have around 150-200kg yet to remove so will concentrate on that

Ethically don't worry too much, there are not many fossil fuels left 🙂

[mohammad]

@Nathan thanks for the prompt response.

Alot of modern hybrids including the prius come with 1-2kwh of battery capacity and a 10 year warranty. Similar to a block heater ive been curious why people dont figure out how to charge the battery up before every trip to increase fuel economy especially on short trips. It could maybe even be wired up to the block heater so its just a single cord to plug in.

[Nathan jones]

Hi Mohammed and welcome to ecomodder. You have given me things to think about.

I do understand, and yes 200v is easy to charge.

This I will think about. Especially when cold weather and my car is in open loop mode all the time (where for a while 30% roughly more fuel is used to warm the engine). I have not tested the idea but it's possible my car rarely uses the O2 sensor to fine tune fuel trim at all...

Generally however at +90mpg until super reaches £2.40/l petrol is cheaper. At a crossover point that 30% will mean your idea would make a very big ethical change and start to save (small at first) money.

There will be transfer losses in changing the house AC to DC to a point less than 30%.

Yes your idea is sound in my opinion.

A full charge like that would contribute 5% to my daily trips as I live in the country (10-15 miles) It would also make the batteries warm and less resistant in the winter (springy like after a long drive. However at my gf's maybe up to 40% of small trips.

I wouldn't wire it to the block heater (don't have one) but the post relay terminals are easy to get to. If you did it overnight you wouldn't need a super thick cord as it's 201v dc, and it normally has to be much thicker (like an inch!), personally speaking. Have the charger/adapter so it goes in the boot.

City definitely. In my case whatever energy I use less mass means more money

Was interesting thanks
Regards

....I also had a thought why electric cars don't have multiple removable modules for people who live in flats etc, like you switch them out...

[mohammad]

Originally Posted by Nathan jones

....I also had a thought why electric cars don't have multiple removable modules for people who live in flats etc, like you switch them out...

Battery swaps dont work for 3 main reasons

1. all ev's use batteries of different dimensions and capacities. the new tesla has a "structural" battery pack. i.e you can't remove the battery it holds the car together. there are no frame rails on the sides of the battery. the front and rear subframes bolt direct to battery

2. Batteries are very heavy and located under the vehicle

3. Most importantly batteries are consumable. if you bought a new car why would you ever want to trade your battery in for one from a decade old crap ass car who just dropped off his battery in your apartment complex? what if you want to move to a house one day, how do you ensure that you get to take your good battery with you?

On a side note there's a new car company in canada thats selling the electric car without the battery and you are suppose to rent the battery from them and they give you "Free" battery replacements for life.

your apartment/condo is legally obligated to allow you to install a charger in your parking spot where i am. An overnight charge makes a lot more sense considering the factors above and that night electricity is over 50% cheaper here.

you are correct that more mass means more energy, but schools and some gyms and some malls offer free charging where im located, To be fair you probably are not going to retrofit a J1772 connector to take advantage of the free chargers though.

if you dont mind me asking why do you use premium gas if your goal is to save money?

[Drifter]

Originally Posted by mohammad

@Nathan thanks for the prompt response.

Alot of modern hybrids including the prius come with 1-2kwh of battery capacity and a 10 year warranty. Similar to a block heater ive been curious why people dont figure out how to charge the battery up before every trip to increase fuel economy especially on short trips. It could maybe even be wired up to the block heater so its just a single cord to plug in.

Toyota tries to keep their NiMh batteries at ~60% charge because the batteries last when maintained there. The battery was really only meant to keep running the car's accessories when coasting or stopped at a light. If you manually charged that battery pack to 100% they would degrade much more rapidly - especially if you didn't have a good battery management system to keep temperatures in an ideal range.

If you were willing to accept consuming a $2,000 battery pack with some regularity, you'd be looking at a maximum capacity ~1.2kWh going from 100% to 0% charge which might get you 3-4 miles on flat ground. If you used a more reasonable 80% to 20% you'd get about 2-2.5 miles of range.

The plug-in prius came with an 4.4 kWh lithium ion battery pack and was rated for 11 miles (2.5 miles per kWh). The prius prime came with an 8.8 kWh lithium ion battery pack and was rated at 25 miles (2.8 miles per kWh).

Interesting, if Nathan Jones wanted to drop 40 lb he could replace his Toyota NiMh battery pack with an Project Lithium battery pack: https://projectlithium.com/

[Nathan jones]

You are right. Plus often my battery is still well charged from the day before. Like I said something I would do in the city but then I would not buy a Prius

I've seen the new packs. Still have my 18 year old one doing ok plus a spare but once my doors and roof are changed or it breaks something I might consider. One reason I would not add batteries

Also there was this
In 2015 BASF produced a modified microstructure that helped make NiMH batteries more durable, in turn allowing changes to the cell design that saved considerable weight, allowing the specific energy to reach 140 watt-hours per kilogram

https://sustainableskies.org/basf-nimh-battery-rebirth/

Haven't seen one around yet though..