Got a new UFO*: 2000 Honda Insight 5-speed (ailing IMA hybrid battery pack)

[3-Wheeler]

Metro,

You can use Mike Dabrowski's schematic and build a very inexpensive charger as I did, and shown here....


Picasa Web Albums - Jim - Battery Trick...


Jim.

[MetroMPG]

Hi Jim -

Exactly! I've got the parts & schematic. Just need to assemble it.

(I'm actually re-assembling a charger that I got from another ex-Insight owner, but the connections left a lot to be desired, so I pulled it apart to re-do.)

Darin

[RobertSmalls]

Darin,

I heard that you've disabled the electric power steering. I'm not really a fan of power steering in general, with the "squishy" and unpredictable feel in the steering wheel. But thinking it would save only a little fuel, and not being able to convince myself it wouldn't affect safety, I've left my power steering in place. After you've driven it around town without power steering, please let us know what you think.

Robert

[MetroMPG]

First, I should say I'm under no illusions that this will save much fuel. The electric system is pretty efficient as is - and it only draws power at low speeds (or high steering effort). But I'm squeezing the car for the competition.

I've experienced the "unpredictability" of this electric assist, but I can point the finger at myself for that because it only (sometimes) happens when I key off and back on again. Sometimes the assist takes a moment to return. Is that what you're referring to?

All that being said, my initial impression, minus assist, is that it's absolutely no more difficult to steer than my Metro/Firefly or the ForkenSwift (factory manual steering). Granted, I also run slightly elevated tire pressure which makes low speed steering easier.

It's a simple fuse removal (under hood) to try it. And it wouldn't be hard to rig a switch to enable you to turn it back on from inside for other drivers or if you're suffering from a particularly harsh arms & chest day at the gym!

I'll report back when I have some more distance with this mod.

[MetroMPG]

I also disabled the rear defroster (fuse pulled from the under hood fuse block).

For those not familiar with this strange quirk of the Insight: the owner's manual states that the rear defroster comes on for 25 minutes every time you start the engine when the coolant is at ambient temperature, regardless of what the ambient temperature is. (Even if the cabin switch is in the off position.)

I haven't tested to confirm, but if true, it's not an insignificant load - it's a 30 amp fuse!

For now I just pulled the fuse. As with the electric power steering disable, it wouldn't be hard to rig a switch + relay to re-enable it from the cabin (meaning 2 switches to turn on the defroster grid).

EDIT: I have to wonder if there isn't some other reason that Honda did this, since it's not well thought out from a safety or efficiency standpoint. It almost seems like they needed to see a 12v load on cold starts for some other reason and just said, "hey, why don't we use the rear defroster on a timer for our load?"

[MetroMPG]

Robert: could you summarize your DC-DC switch/disable modification? I read your thread on IC. Anything further to report since then?

[RobertSmalls]

Originally Posted by MetroMPG

Robert: could you summarize your DC-DC switch/disable modification? I read your thread on IC. Anything further to report since then?

I followed Mike Dabrowski's suggestion there.
In a stock Insight, the MCM pulls DVINH low to turn off the DC-DC converter. If the engine is off and the high voltage battery is depleted, the MCM needs to be able to turn off charging to protect the HV battery. The ECU will also disable charging for a few seconds if you go above ~3500RPM.

What I did was cut the DVINH wire. Leave the MCM side dangling. Wire the DC/DC side to a toggle switch on the dash, and hook the other leg of the toggle switch to ground:
DVINH (pin 6) at DC/DC-----toggle switch-----gnd

The result is that you've revoked the MCM's authority to inhibit DC/DC operation, and given that authority to a toggle switch.

I think if you spliced into the wire instead of cutting it, then either the MCM or the toggle switch could turn off the charging system. That's probably the better way to do it.

On an Optima Yellow Top D51 battery, I got about 2/3 of the way around Seneca Lake before I had to turn the charging system back on. No battery likes being cycled, so this is really not my favorite mod.

[Flakbadger]

Originally Posted by MetroMPG

The rear defroster comes on for 25 minutes every time you start the engine. [...] It almost seems like they needed to see a 12v load on cold starts for some other reason

I could see it being needed for some intricate electrical reason (like it make sense in a way), but 25 minutes? That's friggin' insane! You might as well start the car with the AC on full or something. It does sound awfully wasteful.

[MetroMPG]

Robert - thanks very much for that. And rest assured I understand the limitations & challenges of using this mod.

It may come in handy closer to the the tail end of this weekend's economy competition...

---

Flakbadger - I agree: wasteful, odd and somewhat mysterious.

[jamesqf]

Originally Posted by MetroMPG

It almost seems like they needed to see a 12v load on cold starts for some other reason and just said, "hey, why don't we use the rear defroster on a timer for our load?"

There doesn't seem to be any adverse effect of not having that load. I got rear-ended maybe 5 years ago, breaking the hatch glass & bending the frame just enough that the glass couldn't easily be replaced. So no rear defroster (the hatch has a vinyl/sailcloth covering), but no problems.