There is no other way to be accurate. Miles/gallons. Anything the dashboard shows is just a guess.
Using LifePO4 battery in my 2024 Honda Accord Hybrid for great mileage. Your thoughts?
- Thread starter PetitFrereArmada
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Why Don't Cars and Trucks Use Lithium?
Electric vehicles aside, which use a specially designed type of lithium-ion battery for EVs, LiFePO4 batteries are not recommended for use in extreme cold conditions. While you can use lithium iron phosphate batteries in sub-freezing temperatures, you cannot and should not charge LiFePO4 batteries in below-freezing temperatures. Charging them in sub-freezing temperatures can cause lithium plating, a process that will cause a loss of battery capacity and also cause short circuits, causing permanent damage to the battery.Why Aren't Lithium Batteries Good for Starting?
The issue isn't necessarily with the power output of the batteries. Lithium batteries provide ample power for most starting situations. The problem lies in how the battery is used in starting situations, how the battery is charged and the working environment.Starting
When you hop in the car and turn the key, the starting battery needs to release a very large amount of current to get the starter motor spinning to crank the engine. This extremely large amount of current, even if it only lasts for a second or two, will activate the battery management system (BMS) in the lithium iron phosphate battery, rendering the battery useless requiring a replacement battery to be installed.Charging
Most vehicle charging systems are engineered for use with lead acid batteries, not lithium. If the battery shuts down if the BMS gets tripped, the excess power from the alternator could be too much for the vehicle's electronics to handle and could cause thousands of dollars in damage to computers, sensors and wiring.Honda and other hybrid OEMs know that some of these cars are capable of gaining significant fuel efficiency.
Sadly, the way cars are built now with many options and safety features, they are getting too heavy to benefit from getting better mpg. Do you know that in the Toyota Camry lineup the trim with the best mpg is the base trim LE model. Very few consumers want the base model of any vehicle. So if Toyota or Honda wanted to increase efficiency, they would build a car with less features and fewer safety gadgets. Nobody would want that. Also, car manufacturers do not make billions making base model cheap cars. So they make more from adding options and inflating the prices. You put those options on a car and you make it heavy and it loses its efficiency.
Also, the people who call themselves hypermilers drive differently. Go and look at the old generation Toyota Prius drivers who call themselves hypermilers. They do some crazy things to their cars and drive very differently to achieve over 70 mpg. Some people on here will know what I am talking about. So even if a car company makes such a car, it does not mean everybody will always get the same mpg number. Driver input, terrain, state of the car and other things affect your mpg. Also, some people do not care about their mpg, while some people care a lot and call themselves hypermilers.
Imagine 55-60 MPG not being good enough… Have mercy. LOL.
I strongly disagree. You may consider it as a guess, but it is a very good guess.
On the Accord forum, they have argued a lot about this and have concluded that when they calculate it at the pump, most often the difference is off by 1 or sometimes 2. That means for my best tank of gas where I drove over 750 miles and got 65 mpg, it was calculated manually to be 63 mpg after driving for 750 miles. That is excellent gas mileage.
Talk to most people who have calculated. Even on the Camry forum. Some people claim it is exactly the same while some say it is off by 1 only.
That concludes that what the car show is a very good guess and it may be off by a maximum of 2 mpg on the Accord or the Camry. I do not know about the other brands.
There is no car in the US market that to my knowledge has approved Lithium Iron Phosphate batteries for use in vehicles nore the NHTSA has approved such.
Anything electrical wrong with the car and they will point right away to use of an unapproved battery for automobile use. It's a huge gamble with ZERO benefit. Your mileage numbers are already suspect.
Yep just asked a master tech at our Honda dealer and yes the warranty will be void with this battery.
The 12V battery in an Accord Hybrid does nothing more than power up the electronic for power on. If the ICE engine starts at that point, which it may or may not do, it's the high voltage battery pack that starts it. The 12V battery does very little so it's discharged very little so the amount of fuel used in maintaining its charge is very little.
I can tell you that 55 mpg around town in warmer weather is typical for my '18 HAH and I've had a few tanks of over 60 MPG and this is based upon filling the tank to the brim and then doing the division. I'm about 400 miles into the current tank and total range is showing a little above 770 miles. I'll also say that the car typically displays conservative fuel consumption numbers and does not overstate fuel mileage.
You seem to be doing very nicely with your HAH but there is no conceivable way that a swap of the 12V battery could help with that. More likely that fuel economy is improving as your car is breaking in.
I can tell you that 55 mpg around town in warmer weather is typical for my '18 HAH and I've had a few tanks of over 60 MPG and this is based upon filling the tank to the brim and then doing the division. I'm about 400 miles into the current tank and total range is showing a little above 770 miles. I'll also say that the car typically displays conservative fuel consumption numbers and does not overstate fuel mileage.
You seem to be doing very nicely with your HAH but there is no conceivable way that a swap of the 12V battery could help with that. More likely that fuel economy is improving as your car is breaking in.
You know the US is slow to adopt new technology. We have a very high bar for safety and technology. Products have to go through very tough processes and tough regulatory bodies before they can be approved for mass use in the country. Some people have to give up during the process while some products just do not meet the minimum required score to pass approval. So just because we do not have something approved here in the US does not mean it is a bad thing.
The good thing is that I am driving a Honda. Knock on wood. I hope it never has any problem.
My last Honda was a brand new 2020 Honda Accord Hybrid base model. I owned it for 3 years and put exactly 103,000 miles on it before I traded it in for this 2024 Accord Hybrid. I did not have a single problem with it. I never took it to the dealership for anything. I did all the regular maintenance.
So I hope my 2024 Accord will be as problem free as my 2020 accord was. So no warranty problem on my end.
On the Accord forum, we have had many people go to the dealership for warranty issues. I am glad I have not had to go and I hope I never have to go. I am glad I drive a Honda. I hope it was well built.
Does not change the fact your warranty is void with this battery. Why use it it's not worth the gamble.
Welcome and thank you. Now you are speaking my language. Some people here do not believe that we can get over 60 mpg in our Accord hybrid. They say what proof do we have and they do not believe it. Thank you for sharing that you also get over 60 mpg many times. I do believe you because I do get the same.
The only reason I am using this battery is for an experiment. The guy who did it on the forum claimed and showed pictures of his car getting over 67 mpg in over 10,000 miles. So I decided to experiment and see. But my experiment is only while I am in the city driving or driving where the posted highest speed limit is 65 mph.
If I have to go out of town where the posted speed limit is 75 mph, then I will cancel the experiment and re-start it again only when I return back to town and fill up my gas tank again.
My understanding is a typical car's low voltage electronics or those kind of systems don't use more than 1-3% of the total mpg. Switching from a smaller to a larger 12V battery won't do 10% improvement. If it is a traction battery improvement in hill terrain I would believe it, but not a 12V battery. Even if the battery and all the electronics is lossless it still won't.
I would look at the long term mpg by how much fuel you pump vs how many miles you drive, instead of the instant readout on the dash that might be confused at certain point during your drive.
I would look at the long term mpg by how much fuel you pump vs how many miles you drive, instead of the instant readout on the dash that might be confused at certain point during your drive.
Highway driving is kryptonite to hybrid fuel economy, as is the kind of prolonged cold weather Texas doesn't see much of. AC use has an easily seen impact, since I'll see 55 mpg or so with lots of AC use and 57-59 mpg without it or with merely minimal use in local driving combined with my commute.
Under conditions where you'd expect 55 mpg in local driving you'll barely break 50 mpg with highway use and the cruise set just above the speed limit.
During the four coldest months of the year, I see an average of around 44-45 mpg.
I'll add that on resetting Trip A after a fillup, I can usually see 199.9 mpg while still in EV mode for a bit. This is the apparent limit for the display.
Finally, the HAH is pretty remarkable in its ability to deliver good fuel economy along with reasonable passenger comfort, good handling and ample trunk space.
The fuel usage calculations should be accurate. As long as the injectors are in good shape.
The distance however, far from accurate.
Genuinely curious, if all functions in a hybrid car could be ran off of Li ion batteries, why do hybrid cars even have a lead acid battery? Why wouldn't all electrical energy demand be pulled from the primary Li ion battery pack, and just eliminate the lead acid? This would same money, weight, space, and complexity. Less demand on the BCM. No battery tray. Fewer battery cables.
Being a motorhome guy, I've done a little research into Li ion batteries. I was under the impression that they are not well suited for the sort of current demand that a starter puts on them. I do understand that a starter for a small engine, as is in most hybrid cars, doesn't pull near as much current as the starter on a larger engine. But it is still a pretty good spike. Can anyone here say with certainty?
Being a motorhome guy, I've done a little research into Li ion batteries. I was under the impression that they are not well suited for the sort of current demand that a starter puts on them. I do understand that a starter for a small engine, as is in most hybrid cars, doesn't pull near as much current as the starter on a larger engine. But it is still a pretty good spike. Can anyone here say with certainty?
Nobody is arguing what you’re getting for MPG. The car is efficient. Agreed.
The claim that you experienced a big increase because of a different 12V battery is the point of contention.
You have discovered the latest in a long line of specious claims - the 100 MPG carburetor, the magnetic fuel alignment device, and the intake “vortex” booster, for example - miracles of efficiency “improvement” that simply made no sense from an engineering or basic physics perspective.
You claim the what - better efficiency - and maybe you see a result. That results has dozens of potential explanations, but you choose to believe that it’s your battery. That’s your belief, and since you haven’t shown how you controlled for all the other variables, it remains belief.
What you cannot prove, and where your explanation falls short, is “how”.
How does this battery take that much load off your engine?
How does it increase your MPG?
Miracle alignment of fuel molecules in the line via magnetic force? Nope, that’s been claimed. Better mixing of fuel and air via a stamped piece of sheetmetal in the intake? Nope, that’s been claimed, too. Secret technology suppressed by big oil? Yeah…claimed, as well.
Which leaves you believing, and claiming, that your 12V charging circuit was responsible for about 5 MPG. Call it the difference between 55 and 60 MPG. Which are your numbers, right? A bump from 55 to 60 MPG?
At 60 MPH, that is a burn difference of 0.08 gallons, give or take, or roughly 10,000 BTU.
So, 10,000 BTU saved in an hour, is a load of 3,000 watts. So, your battery is saving 3,000 watts at 12V - dude that’s 250 AMPS.
You want us all to believe that your new battery takes a consistent 250 fewer amps to charge than the last battery.
You are claiming that the electric use in your car went down by 250 amps on the basis of a battery?
250 amps?
You’re going to have to do better than that.
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Many new hybrid cars don't even have a starter. They only use the motor that's hooked to the engine's output.
I think that the cost of having two sets of electrical equipment, for the different voltages, would be the reason they use 12v (14v) for many of the common systems.
1 Can’t get you pictures to work.
2 Anyone that says your “ Warranty is void” is an idiot. Which is not to say that repairs related to the battery and electrical system are going to be covered under the warranty.
3 hope it doesn’t get cold where you are or that something other than this battery can start and power the car.
2 Anyone that says your “ Warranty is void” is an idiot. Which is not to say that repairs related to the battery and electrical system are going to be covered under the warranty.
3 hope it doesn’t get cold where you are or that something other than this battery can start and power the car.
LMAO I certainly will trust a fully certified 30 plus year Honda Tech over anything you say. I can assure you any Honda dealer will look for ANYTHING to void a warranty that's a fact.
Noooooooooo. I am not claiming anything at all. This is an experiment I am doing. I will draw conclusion months from today.
EXPERIMENT: I am trying to see if using the LiFePO4 battery will help me consistently get over 65 mpg in city driving.
With the oem normal lead acid battery, I do get 55 to 60 mpg as my normal. When I focus on hypermiling with the oem lead acid battery, I do get 60 to 65 mpg. I can get those numbers with some serious effort.
Then this guy on the forum bought this LiFePO4 battery and posted some ridiculously high numbers. Basically, nobody is believing him, he posted similar odometer pictures that many of us have posted. Pictures of his odometer showing over 67 mpg in over 10,000 miles. Well, that is what his car is showing. But still, many people do not believe him at all. But the picture is of the same kind of odometer that many of us have posted on the forum and can read to say that picture says that car has done over 67 mpg in over 10,000 miles.
I am just very curious and wish to achieve such numbers. I bought this battery with the hopes of seeing over time if I will be consistently getting over 65 mpg.
I just installed this battery 2 days ago. I still have many months of use for me to draw any conclusions. Right now, I am just hypermiling to see how things will go. The battery has been in the car for only 3 days now. I plan to draw any conclusion many months from today. By then, I hope the battery has not ruined something on my car. But I do not think it will.