Still possible to be an idiot even though you drive a hybrid
#11
Re: Still possible to be an idiot even though you drive a hybrid
ElanC,
Keep in mind that there are a couple of units (probably called the ECM and BCM - just like on the Insight) that prevent overcharging or undercharging. It's bad for the NiMH batteries in the pack to have more than an 85% charge or less than a 15% charge. Note: these figures could be wrong - esp. the 15% one - it's probably raised.
Keep in mind that there are a couple of units (probably called the ECM and BCM - just like on the Insight) that prevent overcharging or undercharging. It's bad for the NiMH batteries in the pack to have more than an 85% charge or less than a 15% charge. Note: these figures could be wrong - esp. the 15% one - it's probably raised.
#12
Re: Still possible to be an idiot even though you drive a hybrid
Originally Posted by Delta Flyer
ElanC,
Keep in mind that there are a couple of units (probably called the ECM and BCM - just like on the Insight) that prevent overcharging or undercharging. It's bad for the NiMH batteries in the pack to have more than an 85% charge or less than a 15% charge. Note: these figures could be wrong - esp. the 15% one - it's probably raised.
Keep in mind that there are a couple of units (probably called the ECM and BCM - just like on the Insight) that prevent overcharging or undercharging. It's bad for the NiMH batteries in the pack to have more than an 85% charge or less than a 15% charge. Note: these figures could be wrong - esp. the 15% one - it's probably raised.
#13
Re: Still possible to be an idiot even though you drive a hybrid
Yeah when the meter shows full, the batteries are only at about 80% actual capacity. Same for zero bars, about 20% is really left.
Actually I never heard that fully discharging NiMH batteries was bad for them (unless you leave them discharged for a while, then they tend to short out, because the self-repairing membranes expend charge in the self-repair process). I have read a lot on NiMH tech and not seen that one before.
The problem may be that NiMH batteries tend to have slightly different capacities, thus when the first battery goes empty, the others will still force current through it. That can cause what is called cell reversal, effectively creating a dead cell in the pack. Don't know how many dead cells it takes before the computer will declare a dead pack. Likely that is what they are trying to avoid. We have heard that the HCH cells are capacity matched, presumably reducing the variation enough to where 20% reserve is a wide safety margin, allowing for the long warranties they provide.
Overcharging is a different story, that is always bad, especially at high charge rates. Older smart chargers used to back off their charge rate for the last 20% of charge which took as long as the other 80% did (new ones use a technique called constant pulse charging which mostly eliminates the need for the back-off). The HCH doesn't have the luxury of slow charging the last 20%, and I don't think constant pulse scales to the massive amperages the HCH uses, so it just quits at around 80% full. A pretty decent compromise aimed at maximizing battery life.
Maybe that unravels the mystery a bit?
Actually I never heard that fully discharging NiMH batteries was bad for them (unless you leave them discharged for a while, then they tend to short out, because the self-repairing membranes expend charge in the self-repair process). I have read a lot on NiMH tech and not seen that one before.
The problem may be that NiMH batteries tend to have slightly different capacities, thus when the first battery goes empty, the others will still force current through it. That can cause what is called cell reversal, effectively creating a dead cell in the pack. Don't know how many dead cells it takes before the computer will declare a dead pack. Likely that is what they are trying to avoid. We have heard that the HCH cells are capacity matched, presumably reducing the variation enough to where 20% reserve is a wide safety margin, allowing for the long warranties they provide.
Overcharging is a different story, that is always bad, especially at high charge rates. Older smart chargers used to back off their charge rate for the last 20% of charge which took as long as the other 80% did (new ones use a technique called constant pulse charging which mostly eliminates the need for the back-off). The HCH doesn't have the luxury of slow charging the last 20%, and I don't think constant pulse scales to the massive amperages the HCH uses, so it just quits at around 80% full. A pretty decent compromise aimed at maximizing battery life.
Maybe that unravels the mystery a bit?
#14
Re: Still possible to be an idiot even though you drive a hybrid
This just shows how stupid Honda is. They'll go to the ends of the earth to stop you from locking the car manually in an effort to prevent you from locking your keys in the car, but they're perfectly happy letting you leave the lights on all day. Whatever.
#15
Re: Still possible to be an idiot even though you drive a hybrid
Wait, does the 06+ not have a headlight alarm? My 97 lets out a very loud tone alarm if you have the engine off, park or headlights on, and open the driver's door. That's worked well enough for me in the 9 years I've had it to never get in such a situation.
#16
Re: Still possible to be an idiot even though you drive a hybrid
Originally Posted by AZCivic
Wait, does the 06+ not have a headlight alarm? My 97 lets out a very loud tone alarm if you have the engine off, park or headlights on, and open the driver's door. That's worked well enough for me in the 9 years I've had it to never get in such a situation.
It does chime if you leave headlights on and open the door, but not if you leave on the dome light or any other drain on the battery. Also, when I drained my battery, I thought the dome light was set to "door" not "on" so when it was on as I was getting out (in a hurry) I didn't think anything of it. It also doesn't chime if you accidentally switch the headlights lights to the middle positions for parking lights rather than the off position. (I've known people who have drained batteries that way)
#17
Re: Still possible to be an idiot even though you drive a hybrid
You can get a portable jump starter at Wal-Mart or most auto parts stores for $30 or so. To charge it, simply plug it in to your house current. AAA uses them nowadays on roadside assistance calls. Get one -- it beats the heck out of having to ask someone else to assist you, and will be a lifesaver if no one else is around.
#18
Re: Still possible to be an idiot even though you drive a hybrid
Originally Posted by zimbop
This just shows how stupid Honda is. They'll go to the ends of the earth to stop you from locking the car manually in an effort to prevent you from locking your keys in the car, but they're perfectly happy letting you leave the lights on all day. Whatever.
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11-27-2005 11:14 AM