Can you run an HCH2 CVT with a dead NiMH battery?
#11
03-06-2009, 08:55 AM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
No, that simulates a completely missing battery. A failed cell or two will not cause the NiMH bus to drop to zero, it'll cause a drop of about 1.2VDC/cell, which if there are only a couple of bad cells, the rest of the battery pack will mask. A more realistic simulation would be to place a low-ohm, high-watt resistor (such as those used to bleed the high voltage bus of a large variable speed drive or UPS system) across one or two cells. Your dash should light up like a Christmas tree on LSD, but the car remains driveable (assuming, of course, that you consider the Yugo-like response we get when going through recals "driveable").
Regardless, it's still in everyone's best interest to get a new battery. What's the point of having a hybrid if you can't take full advantage of it?
Regardless, it's still in everyone's best interest to get a new battery. What's the point of having a hybrid if you can't take full advantage of it?
I have seen this term "recal" in various posts, but I really have no idea what it is. Can anyone explain it to me?
#12
03-06-2009, 10:23 AM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
A "recal", or battery recalibration, is when the car's monitoring system has determined that the NiMH battery pack isn't delivering what the AI thinks it should be. This is generally the result of all the little efficiency losses as current travels down a wire, wide temperature swings affecting how much juice the batteries are able to deliver (cold batts have less available power), and of course the tolerances in the measurement devices themselves.
Basically, the AI says as you accelerate "Hey, electric motor, boost by 150 watts", 150W is sucked out of the battery and is measured as leaving, but only 148W actually gets into the motor windings. Then on the flip side, as you come to a stop sign, the AI says "Mr. Motor, regen by 100W", it sees 100W headed for the battery, but because charging is never as easy as discharging, only 90W actually gets saved. As time goes on, you eventually get to a point where the AI says "Electro-dude, gimme a 150W boost," but like Mr. Scott, the batteries cry out in protest, "But kep'tin, I've only got 20W left. Any more than that and she'll fly apart!" At this point, the AI says, "Oh, ok... let's reset the meter." What you'll see is your SoC (the eight white pips that represent your hybrid battery charge) meter suddenly drop to 1 or 2 lit boxes and the car go from decent performance to Yugo-like sluggishness as the batteries are sucked nearly dry, then go through a forced regen, usually up to (in my car) 7 pips, at which point the AI releases the regen and everything goes back to normal.
It's really hard to say how often is 'typical' for duration between recals. Sometimes I'll go for eight or nine months between them, other times (usually when it's raining for a week or two straight) I'll get one every two or three days. My car really doesn't like late autumn with the wild Ohio temperature swings and crazy weather, but once it gets into "winter mode" (for lack of a better term), it's generally happy until spring or summer.
Basically, the AI says as you accelerate "Hey, electric motor, boost by 150 watts", 150W is sucked out of the battery and is measured as leaving, but only 148W actually gets into the motor windings. Then on the flip side, as you come to a stop sign, the AI says "Mr. Motor, regen by 100W", it sees 100W headed for the battery, but because charging is never as easy as discharging, only 90W actually gets saved. As time goes on, you eventually get to a point where the AI says "Electro-dude, gimme a 150W boost," but like Mr. Scott, the batteries cry out in protest, "But kep'tin, I've only got 20W left. Any more than that and she'll fly apart!" At this point, the AI says, "Oh, ok... let's reset the meter." What you'll see is your SoC (the eight white pips that represent your hybrid battery charge) meter suddenly drop to 1 or 2 lit boxes and the car go from decent performance to Yugo-like sluggishness as the batteries are sucked nearly dry, then go through a forced regen, usually up to (in my car) 7 pips, at which point the AI releases the regen and everything goes back to normal.
It's really hard to say how often is 'typical' for duration between recals. Sometimes I'll go for eight or nine months between them, other times (usually when it's raining for a week or two straight) I'll get one every two or three days. My car really doesn't like late autumn with the wild Ohio temperature swings and crazy weather, but once it gets into "winter mode" (for lack of a better term), it's generally happy until spring or summer.
#13
03-06-2009, 03:25 PM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
A "recal", or battery recalibration, is when the car's monitoring system has determined that the NiMH battery pack isn't delivering what the AI thinks it should be. This is generally the result of all the little efficiency losses as current travels down a wire, wide temperature swings affecting how much juice the batteries are able to deliver (cold batts have less available power), and of course the tolerances in the measurement devices themselves.
Basically, the AI says as you accelerate "Hey, electric motor, boost by 150 watts", 150W is sucked out of the battery and is measured as leaving, but only 148W actually gets into the motor windings. Then on the flip side, as you come to a stop sign, the AI says "Mr. Motor, regen by 100W", it sees 100W headed for the battery, but because charging is never as easy as discharging, only 90W actually gets saved. As time goes on, you eventually get to a point where the AI says "Electro-dude, gimme a 150W boost," but like Mr. Scott, the batteries cry out in protest, "But kep'tin, I've only got 20W left. Any more than that and she'll fly apart!" At this point, the AI says, "Oh, ok... let's reset the meter." What you'll see is your SoC (the eight white pips that represent your hybrid battery charge) meter suddenly drop to 1 or 2 lit boxes and the car go from decent performance to Yugo-like sluggishness as the batteries are sucked nearly dry, then go through a forced regen, usually up to (in my car) 7 pips, at which point the AI releases the regen and everything goes back to normal.
It's really hard to say how often is 'typical' for duration between recals. Sometimes I'll go for eight or nine months between them, other times (usually when it's raining for a week or two straight) I'll get one every two or three days. My car really doesn't like late autumn with the wild Ohio temperature swings and crazy weather, but once it gets into "winter mode" (for lack of a better term), it's generally happy until spring or summer.
Basically, the AI says as you accelerate "Hey, electric motor, boost by 150 watts", 150W is sucked out of the battery and is measured as leaving, but only 148W actually gets into the motor windings. Then on the flip side, as you come to a stop sign, the AI says "Mr. Motor, regen by 100W", it sees 100W headed for the battery, but because charging is never as easy as discharging, only 90W actually gets saved. As time goes on, you eventually get to a point where the AI says "Electro-dude, gimme a 150W boost," but like Mr. Scott, the batteries cry out in protest, "But kep'tin, I've only got 20W left. Any more than that and she'll fly apart!" At this point, the AI says, "Oh, ok... let's reset the meter." What you'll see is your SoC (the eight white pips that represent your hybrid battery charge) meter suddenly drop to 1 or 2 lit boxes and the car go from decent performance to Yugo-like sluggishness as the batteries are sucked nearly dry, then go through a forced regen, usually up to (in my car) 7 pips, at which point the AI releases the regen and everything goes back to normal.
It's really hard to say how often is 'typical' for duration between recals. Sometimes I'll go for eight or nine months between them, other times (usually when it's raining for a week or two straight) I'll get one every two or three days. My car really doesn't like late autumn with the wild Ohio temperature swings and crazy weather, but once it gets into "winter mode" (for lack of a better term), it's generally happy until spring or summer.
Wow, Chris, you really are a mine of information! What a great explanation! This also answers another question I was going to put out on the forum. Once in a while the number of white bars on my battery charge indicator drops like a stone and the IC engine starts up and green recharging bars show up. I was actually sort of wondering whether it was a developing fault on my battery. Sounds very much as though it was a "recal" going on and that that is a normal thing. Thanks!
#14
03-06-2009, 06:13 PM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
I suppose it is possible that a dead pack buggers the DC/DC converter so that it shuts down?
Dang it! Now I'm going to need to do some testing of my own...
#15
03-06-2009, 06:27 PM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
#16
03-14-2009, 12:11 PM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
12v starter is used in extreme temperatures (think Canada winter cold) when using the IMA battery is not desired (it's hard on the battery. Better to be hard on the $80 12v battery than to be hard on the $2500? IMA battery). This is part of Honda's IMA battery self-preservation computer logic.
It's also possible that the 12v battery is used in other odd conditions, dead - no juice or truly dead - IMA pack.
It's also possible that the 12v battery is used in other odd conditions, dead - no juice or truly dead - IMA pack.
#17
03-26-2009, 08:57 PM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
#18
03-27-2009, 06:29 AM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
The Insight Extreame users have posted how to make the IMA generator work to the DC-DC converter to allow gasoline only operation of a civic or insight should the IMA battery fail.
http://www.99mpg.com/mima/faq has the info and some links - good reading mostly for the Insight IMA but works for all Civic IMA (except the MIMA is Insight only).
I was looking for a way to override the IMA logic so that I can get better gas mileage, the MIMA is the way the original Insight can do that.
The site also has pictures of the IMA battery module and the "D" batteries that make it up. ( they also have the Prius battery pictures and have had some put them in their Insights ( requires bigger springs ... )
http://www.99mpg.com/mima/faq has the info and some links - good reading mostly for the Insight IMA but works for all Civic IMA (except the MIMA is Insight only).
I was looking for a way to override the IMA logic so that I can get better gas mileage, the MIMA is the way the original Insight can do that.
The site also has pictures of the IMA battery module and the "D" batteries that make it up. ( they also have the Prius battery pictures and have had some put them in their Insights ( requires bigger springs ... )
#19
03-27-2009, 12:42 PM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
#20
03-27-2009, 01:29 PM
Re: Can you run an HCH2 CVT with a dead NiMH battery?
http://www.insightcentral.net/commun...php?f=4&t=4489
