Project Lithium Nexcell V2

This is off subject, but are you guys saying the 'Range' number is just the gallons in the tank times a set MPG figure?
It doesn't look at how your past or present MPG is being used?
A GOM in an EV uses history and real time info to come up with the 'Guess'.

If this is true, then you could never leave a Prius unattended for 100 days or the HV battery is unable to start the engine.

You could get a HV charger on the HV NiMH pack and bring it back to life.
Not so with a Li-ion pack that has sit for 1000 days.

 

BAAAAM!!! Bill Norton is the man!!! Toyota says the hv ni mh can be stored for years without the need to start up vehicle and will start right up

 

My latest Project Nimh results below

 

I left mine unattended from like May to September one year when my brakes seized up and didn't have time to work on it lol. I stored it at 60-70 ish percent and when i finally worked on it it was still at 60ish % per obd2. So the % loss here is a lot less than you think. I was surprised as well. When i stored it i figured it would have parasitic loss at least like most 12v systems do but honestly it has so little i'm not even sure if it lost any. I just can't remember the individual percent i stored it at.

 

Driving 35 MPH will get you this. It's not complicated. Go Slow.

And according to my bud who drives a Gen 3 as a courier, you can get almost another gallon and a half into the tank after the first 'click'.
So you can game the numbers that way.
I don't do that. I don't want liquid gas in my charcoal cannister.

 

There is no 'parasitic' loss in the HV battery bc when the car is off and the HV contactor is open, the HV is only at the battery side of the contactor and nowhere else.

Whereas, the 12V battery is running all sorts of systems: key fob system, radio presets, blinky red light, gad knows what else....

 

Truth. I didn't know this at the time. I just knew batteries do self discharge in storage from owning thousands of lithium batteries from diy stuff.

 

I have let ours sit a long time. When I start it up battery bars look the same but level drops rapidly (like the reading wasn’t updated while it was asleep and just woken up). I wonder if you noticed this? (I concluded there was a loss but it doesn’t register until you drive it a little bit/maybe 2 - 3 mins).

 

NIMH memory effect. Perfectly normal. The car is just used to partially charging and discharging 24/7 only using the midrange of the battery and the soc calculation isn't accurate for the outer states of charges anymore unless you regularly charge and discharge the battery to the full range of the battery indicator. Which is like 25-80% soc. Which we never really do in hybrids as we don't typically stay in ev mode for long periods of time often (engine off mode).
I don't do that either so i also have the memory effect going on in my battery as well so there isn't a lot of energy available below whatever my typical range of use is at the time.
So say since i have an obd2 gauge that displays state of charge as a percent (soc) if im using 54%-62% regularly there isn't a lot of charge outside of those states so if i hit 53% the battery soc % will rapidly drop to a lower percent until it calculates the correct state of charge again. Which isn't a big deal in normal warmed up driving as when it happens it will charge up again and knock off the crystallization and "relearn" to use those states again and then start discharging linearly to the available level of charge at those states again. The bummer for that is say when you park at half bars, the next morning the car will be at say two bars and get shitty gas mileage until it charges back up again to the range the battery is normally at.
About 6 years ago i just decided to quit using ev mode through the neighborhood at the end of the day discharging my battery more than normal to park my car and just drive the car normally with the engine on and park the car above half bars instead. Netted me better gas mileage as the car isn't trying to recover charge back to the normal range at the rich cold state it starts in every morning.
So there you go, thats a benefit of lithium over nimh.
My tank averages are pretty high typically mid to high 50s year round though.
I will say since i personally only use like 54-62% regularly and up to like 75% ish on long downhill charges there isn't much of a benefit to larger batteries in non plug in hybrid cars gas mileage wise.
With a nominal capacity of 1,310.4Wh 54-62% soc use is around 105Wh and 54-75% is around 275Wh of use.
It will be neat to get a hybrid/ev that uses capacitors one day for say the first 105W of discharge and then discharges and charges the actual hv battery.
Mazda has something like that in use currently but its only a marginally optimized system.
But the benefit is the cycle life is almost infinite and the charging efficiency is extremely high.

 

I haven't been able to pin down the units for self-discharge rates, but I'm assuming they are in % of nominal capacity. Since the actual capacity of a battery may well be more than the nominal capacity, I do not know if the vehicle will start if the battery is at 0% of nominal capacity.

Moreover, low self-discharge (LSD) NiMH batteries were introduced around the time the Gen 2 came out, and these could hold 70-85% (of nominal capacity?) when stored at 20 °C for a year. I don't know if Toyota used that technology for their modules, so I assumed conservatively that they did not to give Project Lithium the benefit of the doubt.

What I was trying to show was that even if the rate of self-discharge was as high as 1% (of nominal capacity) per day, its benefit to fuel consumption would be <1% assuming the car was driven daily. Not to mention that a 1% bump is exceedingly difficult to measure and would be within the margin of error for most analyses. And even if the 1% improvement was somehow proven beyond any doubt, I would likely not switch technologies—if I did, it would take me 244 years to recoup my investment at the current price of gasoline.

Absolutely.

A 35 mph average does not necessarily mean the vehicle was driven at 35 mph the entire time. When driving within the city one will typically go through a range of speed limits from 65 mph (freeways) all the way down to 0 mph (stop signs, traffic signals), and the average speed for that trip will be much less than 65 mph. I drive at the posted speed limit when feasible and coast to red lights, and my average speed is consistently between 20-25 mph just before I reset the trip meter at fill-ups.

@Grit's results could be from a 16.5-hour crawl at 35 mph along a closed racetrack, but I would consider that unlikely.

Why would overfilling result in the gauge displaying a higher than real MPG? It isn't using the tank level to compute those values. In either case, I don't see anything in @Grit's screenshot to indicate that the tank was overfilled.
Volume of fuel consumed = Miles traveled/average miles per gallon = 579.5 mi/65.2 mpg = 8.9 gal
This is well within the tank's capacity of 11.9 gal.
Grit has previously mentioned removing the rear seats, and that weight reduction may well be a contributing factor.

 

Don’t forget my custom aero package that I installed

 

Aero package > 2 click fill ups

 

I understand that.
I was questioning the function of the range display.
In an EV it's called a GOM because it's actively guessing at your range as you drive and how you are driving and how you have been driving.

How does it work in the prius? Is it simply gallons (according to the fuel level sensor) / times a set MPG number?

 

Yes, but driving slow is greatest of all for chasing that MPG number.

I do know you can cram a lot more gas in the tank after the first click. I saw it. I don't do it to my car.
I'm talking about dikin at the filler for minutes, shaking, splashing gas down the side of the car, etc.
My friend has operated his Prii this way for hundreds of thousands of miles.
He is always about to drive the car for hours when he does that nonsense, so......

 

I understand now. I got thrown off because you mentioned gaming the numbers in your response to Grit, and in his screenshots the only game-able figure was the MPG.

I've been keeping pictures of the gauge displaying all the trip stats before fill-ups, but I don't have any pictures from immediately after. The few times that I checked it showed something like 520 or 540 miles of range, and that always turned out to be about 100 miles too optimistic, so I quickly just stopped checking.

 

I think for clarity's sake, we should point out that these words apply to a non PHEV in the sense that these batteries will not get you crazy mpg gains. For me, not having a non PHEV I might be wrong in the first sentence but, others can keep me honest.
Separately, your claims of being similar or typically worse cycle life is an opinion, and without some data to back it up, why even say things to diminish any potential gains all of the owners' butt dyno can notice a difference in?

What I know now, I can use the Tesla cells in my PHEV... It doesn't sound like you are aware of this...

Personally, I dont care about any warranty, I just want something that will last and not have me thinking the cells are a waste of money just to have a few years go by and they are going bad.

If I didn't sleep in the back of my Prius, I would just piggyback for a total of ~11.8kWh of battery capacity it's just I don't have all of the parts I need to make a CHADeMO chrging work just yet.

Prius Plug-In HV Battery Upgrade from 4.4kWh to 8.8kWh - black_jmyntrn


It's looking like ill be in the 30 miles on a full charge range like the Gen 4 Prium here in a few days.

separately... its looking like ill have a low-cost OBD2 dongle with wifi and Bluetooth that has an SDCARD slot available for storage of the data logs from a Prius. All without the need for a secondary device to control. I mention this because the data I've logged on my PIP and Prime will prove to be valuable data to log before and after a HV battery upgrade. In my head, we would be able to upload the data and have a data visualizer present the data for ease of investigating changes in values depending on what non-factory items were added. I just want it to work wirelessly with TechStream!

 

The butt dyno can't really pick up differences in cycle life, can it?

If a manufacturer is confident of the long term reliability of their product, wouldn't they offer a matching long term warranty to better convey that confidence to the customer? Even the most well-engineered, mass produced product can occasionally fail due to differences in material composition, manufacturing processes, human error, and quality control procedures. A solid warranty is simply a safety net for the rare unlucky customer who winds up with the resulting dud and wants to be made whole.

You say you're not interested in a warranty, so I'm wondering how you'll be able to tell a battery will last longer than 2 years if the manufacturer only backs it up for 2 years.

 

for the goals I have with this car and the progress on the new and improved motion, I'm on how far can we push with all of these thoughts. years later will be here sooner than we think before we know anything regarding this Hybrid Technology.

We aren't even to solid facts or at least with some sort of litmus test we can all agree to have as the standard... when being able to stand on more than the butt dyno or pictures of the numbers on the mileage counters on the dashboard count here.

I really wish folks who recently went from v1 to v2 or other battery change had a good few months of logged data. This entire time, ive tried to tell people its not about lift kits and that jazz. those DIYEVCAR guys have come a lonnnnnng way... mix and match different component parts to make the ultimate Hybrid Vehicle Toyota should've given us.

 

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I wonder if that might fall in the category of "plausible reasoning that hasn't kept up with marketing sophistication."

I'm pretty sure big companies all realized decades ago that warranty is just a game they can pay marketers and actuaries to play.

Acme Widgets and Cut-rate Widgets both have their marketing teams conduct customer focus groups, and both teams learn that customers kind of think a 2-year warranty feels about right. Less than that, they think the widget might be unreliable, and more than that, they don't feel like paying for. And the focus groups figure out the customers' favorite price range, $N.

So Acme spends $M making a really good widget that'll almost always last two years, so they don't need to put much aside for warranty claims, and they put a $N price tag on it and sell it with a two-year warranty, and their business model works.

Meanwhile, Cut-rate makes their own widget with cheap materials and workmanship that only cost them $M÷2, and they ask their actuaries to figure out how much money per unit they need to set aside for the chance of later replacing it, and they add that in, and price it at a little less than $N with a two-year warranty, and their business model also works.

 

You can just keep adding bigger cells and add parallels to build a pack that still has the same voltage.
But with a pack 100% bigger, the Thermal Management System needs to be 100% bigger.

And toyota's method of gently wafting cabin air around the cells won't cut it with a big Li-Ion pack.
They had small resistance heater strips for the Gen1 Prime.
I have know idea how the current Primes handle TMS.

What happens when it's 114* or 14*?
Using a chemistry that needs less TMS tolerances may help, like LFP Li-Ion.

I love DIY, but at some point you'll find that you can buy an EV with everything engineered for you, for not much more, even less!

A raised Bolt
I'd buy that kit!