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Discussion Starter #1
Well, finally had a few free minutes today, so once I was done bolting in "Corey's Big Boy Seat Mod" to raise the front of the seats for better thigh support I had a chance to try out another mod I've been curious about. I will give a detailed version below, or just skip to the end for the summary.

The issue:

Most literature states that light braking kicks in the regenerative braking system with the hydraulic brakes kicking in when more braking is required. In reality, the Insight uses a fairly standard hydraulic braking system such that even under light pedal pressure, the hydraulic system is slightly actuated. The percentage of regenerative braking versus mechanical braking is dependent on how deftly the operator can touch the brake pedal. But even in the best circumstances, there appears to be a slight drag from the mechanical brakes.

In the quest for maximum efficiency, one would need to have pure regenerative braking (and supply the battery pack with the maximum amount of recharging). The regenerative system needs to be triggered independently of the hydraulic system. This brings the question, "what triggers the regenerative mode in the first place?" I had suspicions that the regen may be triggered by nothing more than the actuation of the brake lights as many cars already use a signal from the brake lights to disengage the lock-up torque converter in an automatic transmission.

To test this theory I performed the following procedure:

Materials required - two lengths of 14-16AWG Wire, 1 SPST Momentary switch Normally Open, basic soldering equipment

To get started I stripped ~1/2 inch of insulation off of each end of the two lengths of wire. Solder one length of wire to each terminal of the switch and "tin" the loose end of each wire with solder. Follow the cars brake pedal up to a switch. This is the switch that actuates the brake lights. It should have a connector with a black/white wire and a pure white wire facing the aft end of the car. Insert one end of the tinned wire alongside each factory wire. This is commonly called "backprobing" If you are a contortionist, you do not even need to pull the plug. The wires can also be removed with no permanent damage to the car. Once the wires are inserted and secure, turn the key to the "on" position and press the switch...the brake lights should illuminate. If not, double check the connections. Locate the switch in a convenient location.

In operation, when driving down the road and regenerative braking is desired, simply depress the switch. Your brake lights will illuminate to caution other drivers of your slowdown and the regenerative braking system only will be actuated. This insures that every watt of power is delivered to the battery instead of being burned away as heat at the brake rotors. If at any time you desire more braking the hydraulic brake pedal can be depressed as normal.

Testing - I took a ~5 mile drive through mixed traffic and a short trip on the highway. The modification did not set any codes or appear to affect any systems in a negative manner. So the good news is that it appears to work, and should be fairly failsafe. If the switch were ever to fail to close, you simply will not get regenerative braking until you step on the pedal (system will revert to normal operation as it will if you simply don't press the installed button) If the switch were to stick in the closed position, regenerative braking would be applied, however, you could simply disconnect the installed wires to revert to normal operation as well.

In summary, hooking a momentary switch in parallel to the brake light switch would give the user command of "100% regenerative braking mode" However, I can not vouch for the amount of savings this would generate...in theory it would probably be pretty small. But so is the investment in parts and labor.

I welcome any thoughts or discussion.
 

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Pretty clever. Can you tell a difference between regen only, and light pedal pressure? In other words, how much braking force does regen by itself have?

It may be me, but I feel like I can trigger regen only with light braking, but as you say, the brakes are mechanical (hydraulic) and should move if the pedal is moved.

I would probably use this trick on a particular long decel to an off-ramp I drive every day. But I wouldn't actually need the extra charge, as I rarely drop the SOC more than 1 or 2 bars in my usual driving.
 

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Good job Corey.
Well thought out, easy to do and "cost effective". Welcome to the INSIGHT R&D club.

I respect people who "do" rather than "talk" about it.

I'm not an electrical engineer, just an "old time" mechanic. and have just one question.

Will the "heat management" system on the battey controller still guard against excessive heat during charging? (High charge=High heat)

Your mod is also good for the darn tailgaters on the highway.
Again: A job well done.
 

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Discussion Starter #4
Holicow:

By "seat of the pants" it "seemed" like the car did not brake as hard by just pushing the button (although all bars on the charge indicator were lit) as it would when I tap the brake. (This would seem to indicate that, at least for me, the hydraulic brakes are slightly applied during regen mode)

If you are Fred Astaire on the pedals, you can probably hit the very "sweet spot" where the regen is kicked on but the hydraulic brakes aren't on too much. But me, clonking my size 13's around on those postage stamp sized pedals...maybe I tend to stab it a little harder. This mod is definitely scrounging the last few percent of economy. But the price is pretty cheap!

Willie:

I would expect that all the safeguards that apply when you tap the pedal would still apply when you use the button. All you are really doing is fooling the electrical system into thinking the brake pedal has been depressed while the hydraulic system thinks it has not yet been activated.

As Holicow pointed out, some people may be able to balance on this sweet-spot naturally. Another option could be to adjust the stock brake switch in or out to trip the regen at the earliest possible moment.

I just felt this was a quick, cheap, and easy way to insure that the car is making the maximum use of regen. It would seem to be especially helpful for drivers who routinely coast down for a long distance, or big footed people like me!

Also of note, I had hoped that the button might also act as sort of a "forced charge" setup where one could press the button to go into regen, then apply the accelerator at the same time. However, this does not appear to happen. In my test, when I held the button in and set up regen, then depressed the accelerator, the charge indicator swung into the "assist" range.
 

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That's a neat idea. I'd considered something like that, but I didn't realize that it could be so simple to implement! Is there any way to your knowledge to "regulate" the amount of regen you get? Or will that method only give maximum regen?

As per the assist coming on with the gas, I think that someone made mention of that in a thread a couple of weeks ago. I believe the speculation was that the throttle control took precedence (or at least has a lot more numerical "weight" than) the brake control.
 

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Ingenious!

I just know I'm going to do this little mod in the next few days. Great idea! :D

Hmmmmmmmmm... so the brake lights come on but there is no loss of speed... this is also a great way to get rid of tailgaters without risking a rear-ender... :shock: :lol:
 

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Discussion Starter #8
Foxpaw:

That is an interesting question...every time I pushed the button, the regen went to maximum...unless the engine speed was low, then the charge started dropping with speed.


boogetyboogety:

I wouldn't say there is "no" drop in speed...the regenerative braking does slow the car a bit. But you can be assured that 100% of the vehicles deceleration* is due to regen, not to the hydraulic brakes.


*Note: I'm saying 100% due to the regen, this is neglecting all other frictional forces which would be present under hydraulic braking as well.
 

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Nice Job

Nice job Corey,
I took the lazy way out and backed
off on the brake light switch adjustment
(aprox 1/3 turn) so taking the play out
of the pedal with your foot would do
same(easy to feel). Like your mod
alot better. Where did you decide to
put the switch?
Jack Lee
 

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Corey 872...:

Of course, you're right. Not "no" deceleration, but "very slight." Gotcha.

Which brings up a thought on my Rostra cruise-equipped CVT. I just know pressing your button will kick off my cruise control... ready for me to resume speed by pressing the Res/Accel cruise button :D . I've always disliked that the only real way to get out of cruise (while maintaining the speed memory) is to lightly stab the brake pedal with this setup... which only has the Set/Coast and Res/Accel buttons, but is missing that "middle" button that allows getting out of cruise without tapping the brake pedal. Or pressing both buttons at once, which shuts off cruise but eliminates the speed memory. :x



Ooooh, I'm going to like my Corey Button* even more now...

*Officially named in honor of you-know-who :wink:
 

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Discussion Starter #11
Re: Corey 872...:

boogetyboogety said:
Ooooh, I'm going to like my Corey Button* even more now...

*Officially named in honor of you-know-who :wink:
Thanks for the honor, but as Kevin Dougherty pointed out, he was using his "magic button" a couple of years before I "came up" with it. Although I thought it up and tested it without knowledge of Kevin's work, he was using the same set up long before.
 

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OK, OK, I'm on it...

I'm not used to dealing with such intelligent and selfless people. :oops:

I'll officially call it the KC Button. :lol:

I'm off tomorrow and My Beloved is not, so I'll have time to play. My KC Button will be installed, I'll report later... I'm intrigued by Aaron Cake's observation, so empirical research, here we come... :D
 

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Pedal Pressure

Hi Aaron,
Noticed this to. Could be tied in to the ABS or
sensor on the master cylinder or such. Good
call. I've got the Rostra cruise on the '00 and
will be doing this mod too. Simple and effective.
KC or Corey both, thanks for the original idea.
Nice to be part of such an enlightened team.
Jack Lee
 

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Well I checked my service manual, adn there doesn't appear to be a brake pressure sensor. So I have no idea where the car gets the pedal pressure from...I did some experiments today, and yes indeed, the car does change the amount of regen based on pedal pressure. I always try to do most of my braking through regen.

So, I'm fairly interested in this mod. I have been thinking of adding a small microswitch to the side of the brake pedal. The idea would be that if I just rest my foot on the pedal, I am in regen. But if I need to stop, I just press harder. Sort of like an exaggeration of the stock system. Another idea is to add a button to the shift lever....
 

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Ladies and Gentlemen, Pre-ops and Post-ops...

The KC Button is installed, and here are the results. Remember, mine is a CVT, so some of the results may seem hinky, but I don't make 'em up, I just report 'em... :D

- If you forget to plug the connector back into the brake switch after the mod is completed, the car will start but will remain in Park since depressing the brake releases the safety interlock. :oops: When the car is in Park, you can hear a soft "click" when the KC Button is pressed (and it releases the interlock in the console)...

- After you plug in the connector, the interlock will start to work as intended. Well, almost: You can press the KC Button and put the car in D or R without pressing on the brake pedal! NOT recommended... :roll:

- On the CVT, almost anytime you take your foot off the accelerator, you are in regen mode. The bars are apparent imediately. Only if the bars are absent (at a crawling rate when slowing down) does the KC Button have a regen effect. It is very obvious the vehicle is slowing down, and the bars appear to confirm this action is going on. I am assuming this is NOT the case on the MT Insights, that coasting in neutral with the MT does not cause regen... and you should be able to regen in neutral and coasting with this setup. Curiously, on the CVT, the KC Button has NO effect if the car is coasting in neutral... ?!? :D

- If you are stopped, foot on the brake, in AutoStop, and you depress and hold the KC Button, you can release pressure on the brake pedal and the engine will not start again! You can then depress the pedal again and release the KC Button and alternate untold times without the engine coming to life. Very cool on a downhill slope with a lot of stop-and-go traffic... You can creep forward by releasing pressure on the brake pedal and moving on down... and AutoStop is not compromised! :lol:

- As I suspected, pressing the KC Button disengages the Rostra Cruise while maintaining the memory. For me, this is waaaay coool. If I could figure out a way of having it do this without the brake lights turning on, it would allow me to slow down when my radar detector goes off from behind without the brake lights making it very obvious to John Law that I'm altering speed... :shock: while maintaining my speed memory. But I can live with this setup just fine.

All in all, a cheap, quick, ingenious mod that I'm reasonably happy with. As I observe any other interesting events or uses, I'll be sure to let you all know... :wink:
 

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This is a test that you guys with the KC button should do.

Run at a "constant speed" with the IMA bar down a few bars.
(Level roadway, No load or coast on the engine.)

See if the "charge" system will give a "regen".
(Normally this would be a "silent charge" on the IMA battery gauge. NO REGEN LIGHT)
Which normally takes a longer time to max out the IMA battery.
 

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Discussion Starter #18
Re: Ladies and Gentlemen, Pre-ops and Post-ops...

boogetyboogety said:
The KC Button is installed, and here are the results. Remember, mine is a CVT, so some of the results may seem hinky, but I don't make 'em up, I just report 'em... :D

...
- On the CVT, almost anytime you take your foot off the accelerator, you are in regen mode. The bars are apparent imediately. Only if the bars are absent (at a crawling rate when slowing down) does the KC Button have a regen effect. It is very obvious the vehicle is slowing down, and the bars appear to confirm this action is going on. I am assuming this is NOT the case on the MT Insights, that coasting in neutral with the MT does not cause regen... and you should be able to regen in neutral and coasting with this setup. Curiously, on the CVT, the KC Button has NO effect if the car is coasting in neutral... ?!? :D
At least with my MT, when you take your foot off the gas (at any reasonable speed) you will get a few bars of regen and the engine (I think) enters fuel cut mode.

Coasting in neutral...this will not provide regen in the MT because the transmission is disconnected from the engine. I suspect this is the same with the CVT...the engine is disconnected from the transmission, so no regen. Also, the engine must provide it's own power to idle so no fuel cut in neutral for either car (unless speed drops below ~19 MPH and autostop kicks in)

As far as the "variable regen" some of you observe with variable brake pressure. It is possible I misjudged the Insight brake switch as a simple ON/OFF affair. If it had some type of variable resistance over a short span of distance, that could easily give you a variable regen.

To check, you could disconnect the brake wire plug from the switch and measure the resistance at the terminals of the switch as you move the brake pedal. I will give this a try too. But I can't really recall seeing a difference with pedal pressure, so maybe the 00's don't have this feature or my switch is malfunctioning?

More to come
 

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Verrrrry Interesting...

On a CVT, my AutoStop kicks in under 6-7 mph. If I take off again and accelerate past 9 mph, then upon stopping again the AutoStop stops the engine. But if I speed up to eight mph or less, the AutoStop does NOT engage and the engine keeps running! That's why the "creep downhill" trick is so valuable to me (I seem to have a lot of those in my normal commutes). I would love to have the engine kick off when slowing down below 19 mph... :cry:

What you say about coasting in neutral makes sense, even (or I should say, especially) in the CVT.

I should have mentioned, but I didn't, this may be of interest to someone... on the CVT, the brake pedal actuates not one but two plunger switches, side by side. It was easy enough to determine which one went to the brake lights (pushed the brake pedal with one hand, looked out the back to the reflection of the brake lights, and pressed each plunger down with a screwdriver blade to see which turned the brake light off). For future reference, the brake plunger switch is the one closest to the left side of the car, not the one closest to the center. I have no clue what the other plunger switch controls... does anyone care to hazard a guess, or actually know?

Willie, in normal commute duty, my battery normally stays right at one bar down. I've only seen it at 2 bars down once or twice, unless I was climbing a hill or something. And then, it recharges pretty quickly. Next time I deplete the battery a bit more, I'll be sure to try your trick and report, I'll see if I can tell any improvement in the speed and /or rate of recharge... thanks for the tip! :D
 
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