Optimal Charging(Don't let her coast without applying some brake pressure)

ronandjess2010 · 11-11-2011, 11:47 AM

I've owned my Insight for about 5 months and as I continue to get to know her, I'm picking up on some tendencies, or so I think. I'm posting this to see if any others agree and why or why not.

In the past when slowing down I would simply take my foot of the gas and let the car coast unassisted. My mpg's would go up and I would get 3-4 bars of charge, I couldn't be happier. I've started to notice, that if I apply the slightest amount of brake, my charge bars shoot way up to full and I still slow down very gradually. I do a lot of city driving so for me, maintaining the battery is a major concern. I don't know that this would be as valuable for those that drive a lot of highway. Has anyone else noticed this and studied it more?

Thanks

Eli · 11-11-2011, 11:58 AM

Yes, that is how it works. Touching the brake pedal will cause regen to go to full long before your physical brakes engage. Use this technique to slow down whenever possible and/or necessary to maximize regenerative braking. It's all about modulating your speed, however you need to do that with your driving conditions.

Insight #1 is on the original brake pads at 160,000 miles.

What I do when I'm slowing down is to shift into 2nd gear. This gives you both a higher level of regenerative braking and engine braking. If I need to slow down faster, I will touch the brake pedal. This usually happens towards the end of the stop.

The worst thing you can do for efficiency is shift into neutral and use the friction brakes to stop. Believe it or not, many people were taught to do this and those habits carry over when they drive the Insight.

jerrydelrey · 11-11-2011, 01:45 PM

I usually use Third to slow down.

With a little more planning (slowing down earlier) when your gonna stop. You can get full regen twice the distance in 3rd vs second. When you gebeta 20-18 mph put it in neutral and the engine will go straight to autostop.

The advantage of 2nd gear is you get full regen down to 10 mph.

I have been trying to use second but I just slow down to fast. it feels like I get less time in full regen.

Eli · 11-11-2011, 01:59 PM

I've always used second to stop, and it works well for me. It's not like I find myself slowing down too much or anything, lol. If you're able to keep your battery full, that's all that really matters. Third would definitely be better than 5th though.

With a stock car, regen tapers off before 10MPH though - 10MPH is the limit for 2nd gear as that's when you hit 1,000RPM. With MIMA, I can use regen to slow down to 10-11mph, but any lower and the engine starts to fight with you as the fuel injectors come back on. The stock car starts to taper regen off at something like 15MPH in 2nd, IIRC.. been too long since I drove a stock car regularly.

I'll have to play with trying it in 3rd.. It does make sense. Technically, engine braking is wasting energy... I've never had a problem keeping my battery full though, even less so now with MIMA.

Eli · 11-11-2011, 02:20 PM

Wow, I was way off.. lol.

Just tested it out on my way home to lunch. In 2nd gear, the stock car begins tapering full regen off at 29MPH.

samwichse · 11-11-2011, 02:26 PM

I always used 5th down to 30 (where it suddenly goes from full bars regen to no bars) and downshift to 3rd to regen down to about 18-19. Downshifting to 2nd for regen seems to be how a lot of these cars lost their syncros

I always tried to regen in the highest possible gear, as the lower you go, the more RPMs you're spinning the engine at (but conversely, the ability of the IMA motor/generator to output ampherage is less RPM sensitive). In other words, the more RPMs on the engine, the higher your [engine braking]:[regenerative braking] ratio is.

Now in my HCH, I pretty much regen in 5th (good for down to 21 or so), and sometimes if I'm already in a lower gear, 4th (18 mph cutoff) or 3rd (12mph).

Sam

Eli · 11-11-2011, 02:38 PM

I revmatch my downshifts religiously.

Probably a good thought though.

We need to get out of the habit of saying the "synchros" are the problem with the 2nd gear downshift grinding. They have nothing to do with it.

boogetyboogety · 11-11-2011, 03:37 PM

Years ago,someone here (a forgotten genius, or at least, forgotten by me. Don't take offense, I don't remember what I had for breakfast most days) suggested putting in a momentary-on push-button switch on the dash or console (I chose the three blank plugs on the left of the steering column for mine) wired to the brake light switch under the dash, so that when pressed, the brake lights would come on. Why? Just lighting up the brake lights starts the aggressive regen mode, just as though you've applied the brake, but without the brake wear. The regen mode does a fine job of reducing speed when coming up to a red light, traffic, or other obstacles ahead. And did I mention no brake pad wear!? And traffic behind you knows you're slowing down! And your battery gets aggressively recharged! Win-Win-Win...

It's to the point where I use it to retard my travels more than 80% of the time.

Willie Williford · 11-11-2011, 03:55 PM

That is the "max" regen switch Dick. I can't remember who first did it either. (Got to change my meds). Calpod,?

Willie

Eli · 11-11-2011, 04:15 PM

You can use your foot for the same purpose. You don't need a switch.

When I said touch the brake pedal, I mean touch. The brake pedal switch is very sensitive, it only takes a couple millimeters of movement to turn your brake lights on and cause regen to go to full. This is long before the friction brakes start to engage.