jakespop
Member
Can someone explain the difference between Eco and B mode and how each affects range?
Tips / Tricks about when to use and benefits of each?
Tips / Tricks about when to use and benefits of each?
Eco vs. B Mode vs. Normal
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bbrowncods
Well-known member
ECO makes the accelerator pedal less sensitive. Pretty much makes it so you have to push harder to get the same amount of power. It does not restrict the amount of power. If you push to the floor you will still have the full 80 Kw. The affect is you tend to use less power because it is harder to push the accelerator.
B mode just give you more regen. As an example if you are in D and you let off the accelerator you would possiblely get 10 Kw of regenerative power. With B mode in the same circumstance you may get 20 Kw of regen. The effect is it slows you down quicker. I use it if I am just trying to slow down a little quicker, say in traffic, instead of using the brakes.
B mode just give you more regen. As an example if you are in D and you let off the accelerator you would possiblely get 10 Kw of regenerative power. With B mode in the same circumstance you may get 20 Kw of regen. The effect is it slows you down quicker. I use it if I am just trying to slow down a little quicker, say in traffic, instead of using the brakes.
min68
Member
bbrowncods said:
so you switch between B/D frequently in driving?
tuanies
Active member
I use B mode as a type of engine brake on my wife's Leaf. Works great if you want to slow down faster than normal regen but not quite ready to tap the brakes and set off a chain reaction yet.
bbrowncods
Well-known member
Yes. I am still figuring out how I like driving the Leaf. I have waffled between having ECO on or not. Currently I am trying to see how high I can go with efficiency (miles/Kwh), so I have ECO on.min68 said:
I typically drive in D and if I see or anticipate the need to slow down I start by using the accelerator to hold zero energy usage by the motor, and then switch to B, and then I will use the brakes if needed. I will then put it in D again as I accelerate back up to speed. Typically this pattern occurs in traffic slowing ahead, coming to a stop sign/light, or turning at an intersection or exit. I think it is kind of fun and enjoy trying to maximize my range.
I do try and be courteous and if someone is behind me I will tend to drive more like an ICE, which tends to be stay as fast as you can until the last second and then slam on the brakes to stop. You can really see in the Leaf that this pattern of driving is highly wasteful. In an ICE you just don't have the feedback that tells you as a driver what is occurring. In the Leaf the "Energy Usage" and miles/Kwh meters are valuable in telling you what energy is being burned.
jakespop
Member
Does the regenerative breaking really help extend battery life? what kind of gain can one expect in standard stop/go traffic?
bbrowncods
Well-known member
Well you automatically have some regen in D just by letting off the accelerator. B just gives you more. And then stepping on the brakes gives additional regen. It all goes to slowing you down and beats just having friction brakes like an ICE. It does recharge the battery but I know it is not 100% efficient.jakespop said:
minispeed
Well-known member
You also get more regen in Eco than in normal mode. If you don't like the feeling of driving in eco for acceleration if you push the eco button when you come off the accelerator you will get more regen, not as much as B but I'd say 75% of B by a seat of my pants feel. It's also much easier in traffic to use the eco switch on the wheel than using the D/B shifter.
However for maximum range/efficency you want to use the least regen possible. It's a difficult concept to get over at first. If you're battery is at 100% when you accelerate you lose a % of that because the system is not 100% efficent. The same goes for regen. If you accelerate from 0 to 30 then back down to 0 using regen only you can never put the same amount of energy into the battery as you took out. So the most efficent way to drive is to accelerate to 30 and coast down to a stop. If you did both of those with 2 leafs side by side using the exact same amount of energy to get up to 30 then the leaf that coasted would go further. When the leaf that used regen then drove up to the leaf that coasted it would take more energy out of the battery to catch up than regen had put in.
In the real world you have to find the balance of what works best for where you are. If you have a street with lots of stop signs you can do the coast down, figure out what speed to accerlate to so you can coast to the next stop sign. On a street with lights where you have little warning if the light will go yellow then the most regen possible is the best answer. Shifting into B takes time though, keeping the car in Eco and having extra regen is instant. Eco also makes it easier to modulate the accerator to coast without having to shift into N.
Leaving the car in B at all times can mean that you use too much regen at times (ie light is red but turns green before you stop). In D and Eco you can also use a light foot on the brake to get max regen with little or no friction brakes which will accomplish the same thing as B without the possibility of forgeting to put it back in D or any time delay.
B mode is made for going down mountains without overheating the brakes, that's it. If it gave any range advantage it would be standard so that it would show on the EPA test. As another post mentioned watch other drivers and you'll see that they waste a lot of energy. Regen gets marketed as the top tool to extend range because it recovers that wasted energy from drivers who don't care to save energy. It is the tool that will soften the "your millage may vary" for aggresive city drivers. The EPA test wastes a lot of gas, if you take efficent driving seriously you should be able to beat it in any ICE car. Regen is NOT a tool that will allow record breaking efficency, but just like all tools if the expert knows what tool is best for the exact situation they are in it can be very valuable to them under the right conditions.
However for maximum range/efficency you want to use the least regen possible. It's a difficult concept to get over at first. If you're battery is at 100% when you accelerate you lose a % of that because the system is not 100% efficent. The same goes for regen. If you accelerate from 0 to 30 then back down to 0 using regen only you can never put the same amount of energy into the battery as you took out. So the most efficent way to drive is to accelerate to 30 and coast down to a stop. If you did both of those with 2 leafs side by side using the exact same amount of energy to get up to 30 then the leaf that coasted would go further. When the leaf that used regen then drove up to the leaf that coasted it would take more energy out of the battery to catch up than regen had put in.
In the real world you have to find the balance of what works best for where you are. If you have a street with lots of stop signs you can do the coast down, figure out what speed to accerlate to so you can coast to the next stop sign. On a street with lights where you have little warning if the light will go yellow then the most regen possible is the best answer. Shifting into B takes time though, keeping the car in Eco and having extra regen is instant. Eco also makes it easier to modulate the accerator to coast without having to shift into N.
Leaving the car in B at all times can mean that you use too much regen at times (ie light is red but turns green before you stop). In D and Eco you can also use a light foot on the brake to get max regen with little or no friction brakes which will accomplish the same thing as B without the possibility of forgeting to put it back in D or any time delay.
B mode is made for going down mountains without overheating the brakes, that's it. If it gave any range advantage it would be standard so that it would show on the EPA test. As another post mentioned watch other drivers and you'll see that they waste a lot of energy. Regen gets marketed as the top tool to extend range because it recovers that wasted energy from drivers who don't care to save energy. It is the tool that will soften the "your millage may vary" for aggresive city drivers. The EPA test wastes a lot of gas, if you take efficent driving seriously you should be able to beat it in any ICE car. Regen is NOT a tool that will allow record breaking efficency, but just like all tools if the expert knows what tool is best for the exact situation they are in it can be very valuable to them under the right conditions.
lillyandken
New member
- Joined
- Sep 21, 2014
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I don't know if it works for other people but I used to drive a stick shift and down shift when I get to the red light. I use the B Mode much the same way, except when the battery is 100% seems like the B Mode does't slow it down more (probably to protect the battery).
dgpcolorado
Well-known member
Minispeed, that was well said. The only thing I'd add is that in Eco the accelerator is "power mapped", that is holding the accelerator pedal at a constant position will give the same power, including 0 kW (the equivalent of neutral), at a given pedal position. This mapping makes efficient driving easier, versus D, which has acceleration mapping. [This is on older LEAFs; so far as I am aware it hasn't changed on the newer models.] Those with SV/SL models can see this for themselves by watching the energy display on the center console.
You are correct. Regenerative braking is reduced at high battery charge levels to protect the battery (no place to put the charge being produced by the regen). It is also similar to the tapering of charge as the battery nears full: slowing the charge rate is more gentle to the battery chemistry.lillyandken said:
Bob
Well-known member
Regen does save energy and extend range.
You get some regen just by taking your foot off the accelerator. You get more regen by gently braking. If you brake a little harder, the actual friction brake engages.
B-mode causes more regen when taking your foot off the accelerator as if you gently pressed the brake. But you can get the same effect by gentle braking.
If absolute extreme range is your goal, the most efficient way to drive is to never use regen or friction braking. Anticipate slowing down far in advance. Take your foot partially off the accelerator so that there is only one white bubble showing on the dash. This means you are not using power and not regenerating.
Although regen is good, the electrical process of generating electricity from deceleration and using it to recharge the battery is only ~50% efficient. You lose energy in the motor, in the electronics, and in the battery pack itself. Regen is most efficient at high speeds and least efficient at low speeds. In part, this is because regenerating at low speeds means recovering low voltage from the motor and then boosting the voltage up to battery pack voltage.
Bob
You get some regen just by taking your foot off the accelerator. You get more regen by gently braking. If you brake a little harder, the actual friction brake engages.
B-mode causes more regen when taking your foot off the accelerator as if you gently pressed the brake. But you can get the same effect by gentle braking.
If absolute extreme range is your goal, the most efficient way to drive is to never use regen or friction braking. Anticipate slowing down far in advance. Take your foot partially off the accelerator so that there is only one white bubble showing on the dash. This means you are not using power and not regenerating.
Although regen is good, the electrical process of generating electricity from deceleration and using it to recharge the battery is only ~50% efficient. You lose energy in the motor, in the electronics, and in the battery pack itself. Regen is most efficient at high speeds and least efficient at low speeds. In part, this is because regenerating at low speeds means recovering low voltage from the motor and then boosting the voltage up to battery pack voltage.
Bob
