Honda Insight Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
I own an 01 Insight and am used to 66mpg . I had the battery pack and two control units replaced. Now i can't get over 47mpg in any condition . When driving the car,the battery pack won't charge over 50%. Only when i sit and idle @3,000rpms will the battery charge all the way and then the RPT light comes on,and the cruise won't hold the desired speed yet Regal Honda of Lakeland Fl. says nothing is wrong that everything is working properly . Can somebody tell me how to fix the problem?
 

·
Registered
Joined
·
2,448 Posts
Do you still have the original 12 volt battery under the hood? If so it's likely on it's last leg and really dragging everything else down. Also check the condition of the ground wires in the engine compartment, these are known to corrode, break and cause little deamons.
 

·
Premium Member
Joined
·
1,658 Posts
Resist, when a 12V battery is failing the DC-DC convertor keeps pumping juice into it regardless; this reduces the amount of regen energy going into the IMA pack (see 50% charge above), which reduces the amount of assist and hence MPG.
 

·
Premium Member
Joined
·
4,942 Posts
The Citrus Smoothie said:
Resist, when a 12V battery is failing the DC-DC convertor keeps pumping juice into it regardless; ...
Which is true as far as it goes. :) :) :)

In most other cars this type of 12v battery failure is unusual. But in an Insight with its different 12v battery management it may be much more common. There have been numerous credible anecdotal reports of such. Just remember that if your specific 12v _hasn't_ failed in this way a replacement won't fix it. Hence I support the "don't fix it if it ain't broke" philosophy. ;)

Try an IMA reset first.

IMA reset procedure
http://www.insightcentral.net/encyclope ... orage.html

or simply disconnect the 12v for about 1 min (same thing accomplished as above but its "safer" than messing with the connections at the terminals).

If your problem _stays_ fixed for several days of "normal" driving then your 12v is OK for now and it was your MCM / BCM that slipped into what I refer to as the SoC doldrums. Like any computer sometimes they "glitch" and a reset is necessary.

The "problem" with simply replacing the 12v without this "extra" step is that since a disconnection accomplishes a reset you'll never know whether you wasted your money on an unneeded 12v battery.

HTH! :)
 

·
Registered
Joined
·
182 Posts
Or test the 12 V battery: One way to do that that has been suggested is to run the headlights for half an hour with the car off, while monitoring the battery voltage. Don't let the voltage get below 11 V or you are damaging the battery. A good battery should be able to do half an hour without going below 11.5 V (off the top of my head estimate).

Warning: Don't try this if you don't have a battery charger available or some other way to get started again to go buy a new battery!

Charlie
 

·
Registered
Joined
·
2,448 Posts
I'm going to go out on a limb here and say this type of symptom (though I'm not saying for 100% sure it would be the 12 volt battery, but it could be) is common in any vehicle using a DC/DC converter rather than an alternator for a charging system.

I've talked to the person who does EVBones, a company which supports the S-10E Electric trucks that GM built and sold. They have a DC/DC converter of course and I guess those are known to commit suicide trying to keep the 12 volt battery alive. He said they don't keep a 12 volt battery in there longer than a year no matter what.

The problem is when the battery ages it takes more to charge it and a lot of energy is just burned off as heat. If this battery were in a typical car it wold have probably failed to start the car before it gets too bad. In our case the 12 volt only needs to initially power up the computes and pull in the high voltage contactor long enough for the DC/DC to come alive. So it only takes maybe 2% of the batteries original capacity to start our hybrids, but it reality it's on it's last leg and you would have replaced it in a regular car long before this.
 
1 - 9 of 9 Posts
Top