Honda Insight w/Acura TSX engine - Ecomodding

[Ecky]

There was a thread by redpoint5 about lithium 12v batteries which morphed into a supercapacitor discussion:

https://ecomodder.com/forum/showthre...ent-36566.html

I can give more details upon request (or when I get around to it) but feel free to ask any specific questions.

[19bonestock88]

How badly does the supercap bank self discharge? Take a charge more/ less efficiently than lead acid? No battery in parallel with it?

Where did you get the parts to build?

[Ecky]

Originally Posted by 19bonestock88

How badly does the supercap bank self discharge? Take a charge more/ less efficiently than lead acid? No battery in parallel with it?

Where did you get the parts to build?

These are the caps I ordered:

https://www.alibaba.com/product-deta...27fc3e5fZyJBmC

The caps would probably hold enough energy to start the car for a few weeks (just a guess) but the car has a little bit of parasitic draw on its own and leaving them connected to the car drains them pretty quickly. My DC-DC converter only charges to around 13.6v, so the voltage most cars would top the caps off at would probably last a little longer, but I estimate I have 48-72 hours of standby with no battery, if your car has no more parasitic drain than mine. Or in other words, you can *probably* start a car on a Monday if you park it on a Friday, if you don't disconnect the caps.

I have access to an unlimited supply of lightly used 7 amp hour sealed lead acid batteries at work and the most economical thing for me to do would be to just keep one of these in parallel with the caps to increase my standby time to greater than a week. I had to complicate things though, and added a 20 amp hour LiFePO4 battery, which weighs less than a 7Ah lead acid and has greater charging efficiency. This battery would likely run the starter motor safely on its own in good weather, but it hasn't been above 0F here in around 4 days and anything below freezing is extremely dangerous for lithium batteries. So, I added a 0.3 ohm resistor with heatsink between the battery and caps. The battery only serves to trickle-charge the caps, and, in a pinch - let's say I leave my lights on and run the caps down while I'm in a store - I can just shut them off and wait 20 minutes for the caps to fill back up.

After starting the car with the caps, I hear the fan for the DC-DC converter kick on for around 6-8 seconds, and then they're full again, and it goes back to a low current mode. I have no idea how much energy is wasted keeping a 12v lead acid battery around 14v when driving around, but it's effectively zero with the capacitors.

Another perk is that my car starts just as well at -10F as it does on a warm summer day. Those suckers have some cold cranking amps.

This is similar to the resistor I used:

https://www.mouser.com/ProductDetail...Ju4VZEcCWjA%3d

This is the LiFePO4 battery I ordered:

https://www.batteryspace.com/lifepo4...assed-dgr.aspx

You can get them cheaper without balancing circuits, but I felt it was a good idea.

[hayden55]

Originally Posted by Ecky

These are the caps I ordered:

https://www.alibaba.com/product-deta...27fc3e5fZyJBmC

The caps would probably hold enough energy to start the car for a few ...

Without quoting the whole thing you should make a video showing the setup.

[Ecky]

Originally Posted by hayden55

Without quoting the whole thing you should make a video showing the setup.

I'll see what I can do. It was -15F this morning before wind chill, but I think it's supposed to warm up over the next few days.

[Ecky]

Thought I'd share one of my favorite articles, which I'll be using to aide in tuning this engine:

Honda's K20A Engine

An Imagery of the i-VTEC Implementation











EGR Effect: By swirling back some of the exhaust air back into the combustion chamber, combustion temperature is lowered, and NOx output is reduced.

~

The iVTEC operating principle
This section is the most complex of the whole article. As explained by Honda, we need to look at the operating combinations in a 3D mode now since we have introduced variable valve opening overlap in addition to the two stage cam profiles. Honda identifies 4 major cam variations for the K20A's iVTEC implementation. Of these, variations 1 to 3 are based on the so-called low cams and only variation 4 uses the high-cams. Note that the diagrams shows that VTEC is implemented only on the intake cam.

Now, note that there is an annotation indicating a 'mostly resting (intake) cam' in variations 1 to 3. This is the 'approximately 1-valve' operating principle of VTEC-E. Ie, one intake valve is hardly driven while the other opens in its full glory. This instills a swirl effect on the air-flow which helps in air-fuel mixture and allows the use of the crazy 20+ to 1 air-to-fuel ratio in lean-burn or economy mode during idle running conditions.

On first acquaintance, variations 1 and 3 seems identical. However, in reality they represent two different engine configurations - electronic-wise. Variation 1 is lean burn mode, the state in which the ECU uses >20:1 air-fuel ratio. VTC closes the intake/exhaust valve overlap to a minimal. Note that lean-burn mode or variation 1 is used only for very light throttle operations as identified by the full load Torque curve overlaid on the VTC/RPM graph. During heavy throttle runs, the ECU goes into variation 3.

Lean-burn mode is contained within variation-2 as a dotted area probably for the reason that the ECU bounces to-and-fro between the two modes depending on engine rpm, throttle pressure and engine load, just like the 3-stage VTEC D15B and D17A. In variation-2, the ECU pops out of lean-burn mode, goes back to 14.7 or 12 to 1 air-fuel ratios and brings the intake/exhaust overlap right up to maximum. This as Honda explains will induce the EGR effect, which makes use of exhaust gases to reduce emissions. I believe this is somewhat similar to the principle used in CVCC that Honda introduced on their early generation Civics in order to meet emissions objectives in the early 1970s.

I believe variation-3 is the mode where the ECU varies intake/exhaust opening overlap dynamically based on engine rpm for heavy throttle runs but low engine revs. Note also that variations 1 to 3 are used in what Honda loosely terms the idle rpm. For 3-stage VTEC engines, idle rpms takes on a much broader meaning. It is no longer the steady 750rpm or so for an engine at rest. For 3-stage VTEC, idle rpm also means low running rpm during ideal operating conditions, ie closed or very narrow throttle positions, flat even roads, steady speed, etc. It is an idle rpm range. The K20A engine implements this as well.

Variation-4 is activated whenever rpm rises and throttle pressure increases, indicating a sense of urgency as conveyed by the driver's right foot. This mode sees the wild(er) cams of the intake camshaft being activated, the engine goes into 16-valve mode now and VTC dynamically varies the intake camshaft to provide optimum intake/exhaust valve overlap for power.

[Ecky]

Copying a post I made on IC with some measurements of power consumption:

So it seems the cold moved west, it was up to 8 today with very little wind so I went out and measured the current coming out of the Mean Well unit with various accessories turned on.


Cold idle: 10.9A
Warm idle: 9.9A
4000rpm: 10.0A

Radio low volume: 1.0A
Radio high volume: 1.5A
Running lights: 0.6A
Headlights: 6.8A (plus running lights)
Climate control fan low: 3.1A
Climate control fan high: 9.3A
A/C: ?? Added zero
Wipers: 3.6A at max speed
Rear defroster: 8.3A

I was unable to get the cooling fans in the front of the car to come on in the time I was measuring so I can't say what amperage the A/C or cooling fan will add, but from my testing I could run headlights, max wipers, max air conditioning, rear glass defroster and blast the radio (mine has a separate amp with a subwoofer so draw will be higher than yours) when the car is cold for a grand total of 41 amps, plus those fans up front. More realistic when driving for me would be around 22 amps at night with lights and radio, around ~290 watts or 1/3 of a HP electrical load, and 11-13 amps during the day (~160 watts / 0.2HP).

I realize now I haven't measured power consumption from the caps with the car in ignition position 2 but without the engine firing.

[JQmile]

I dunno if anyone has posted this yet, but this is what I always think of when I hear K-sight lol

https://www.youtube.com/watch?v=VoQbqdMCLHA

[Ecky]

Came across this and thought I'd share. Japanese auto designer Mooncraft built a very unusual Insight:








Can't say I care for the lime green. I appreciate the smaller mirrors and revise front bumper with built-in upper grille block. I can't help but feel if the camera were to pan back there would be a 6 year old holding an RC controller.

[Ecky]

I have a spare bumper, thinking I might try a fiberglass nose modification on it once the weather warms up.