A high-voltage hybrid battery pack can kill you. Even a "dead" one can make YOU dead. If you don't know how to work around & protect yourself from high voltage, don't muck around in there!)
for detailed info about the procedure being followed in this discussion, see DIY Solutions to Honda Hybrid Battery Problems (Insight, Civic, IMA)
Background: dead hybrid pack = good price on a used Insight
Last year, I bought my 2000 Honda Insight
with a "dead" hybrid battery. The "check engine" light (CEL) and "Integrated Motor Assist" (IMA) light were both on.
The local Honda dealer had told the previous owners that the hybrid battery was dead, and would cost ~$3000+ to replace with a new one.
Fortunately for me, they thought a $3k+ repair bill was a bit steep for an 11 year-old car with 269,000 km (167k mi.) on it. So they traded it in at a different used car lot out in the country, and the lot owner was pleased to eventually unload that defective, weird little car on me.
The car had a stored P1449 code
. From what I've been able to gather, it's set for a number of potential IMA battery pack issues:
- cell over 80°C for at least 2 seconds
- pack out of balance (weak cell/s)
- shorted cell
Code reset! Happily ever after?
Resetting the CEL and IMA lights caused the hybrid functions to return to normal!
But only for a while.
The hybrid battery gauge would show recharging while driving or idling, and the electric assist, regenerative coasting/braking, and idle-stop functions worked fine.
But after a while (particularly after sustained charging or assist), the lights would come on again and the hybrid functions would cease.
A "crippled" hybrid that can still get 80+ mpg
Honda designed the car to work even with the hybrid functions disabled. The engine even has a "back-up", conventional 12 volt starter. (Normally it's started instantly & quietly via the IMA motor/generator.)
So I drove the car from July through November, minus the hybrid stuff, and managed to attain 80+ MPG (US) / 2.7 L/100 km over thousands of kilometers and 3 tanks of gas. How? Most of my travels were "driving with load" at moderate speeds (~80 km/h) on secondary highways (mostly flat to slightly rolling terrain) where the car could be held in lean burn mode for extended periods.
But the hybrid stuff is way cool
I could just leave the hybrid stuff disabled, and continue getting phenomenal fuel economy forever. Even without the hybrid functions, the Insight is a marvel of efficiency engineering: light, highly aerodynamic, efficient 3-cylinder gas engine with lean burn, and tall gearing.
I will never make back the money in added fuel savings that it will cost to repair, even if the cost is only in the low-mid hundreds
But ... the hybrid stuff is teh geeky coolness. So I'm going to look at fixing it anyway. DIY, baby!
This thread will document the adventure.
I'll be pulling the pack out this weekend, and I've got myself a $80 NiMH battery/cell analyzer from eBay. Step one is gathering data/characterizing the health of the cells in this pack.
Until then, you may be interested in reviewing Mr Small's excellent thread on this very subject: DIY Solutions to Honda Hybrid Battery Problems (Insight, Civic, IMA)
That's the process I'll be following.
here's an index/summary of this thread's notable posts & milestones:
- Post #20: photos of the pack removed & disassembled here
- Post #35: How long will a complete pack analysis take? About 9 days of steady testing.
- Post #153: Discussion of the DC-DC converter - does it continue to charge the 12v battery while using the car with the IMA breaker switched OFF? Yes (sort of).