2003 Civic Hybrid: refurbishing/cycling the hybrid battery pack

[Formula413]

Originally Posted by MetroMPG

he "forced charging" part is normal after doing that procedure on the pack: The computer's memory of the state of charge (SOC) no longer agrees with the actual state of charge. So when it detects the "extra" juice on board, it needs to recalibrate the pack (by forced charging to try to "top it up" and reset then the battery SOC gauge).

I should clarify that part. It did the same thing it always does if the 12V battery has been disconnected. After starting the car it showed 4 bars of charging for about 2-3 minutes, after which the charge/assist gauge went back to the center. I did this with the car sitting in the driveway. Once I started driving the car it provided weak assist at first, then stopped providing assist and went into forced charging.

[sheepdog 44]

I had the good fortune to get my pack cycled three times a week after my IMA first came on. Thats full topping and discharging. I believe balancing is the key issue. My pack would lose voltage then gain voltage before finally slowly dropping as the pack discharged. I believe the unbalanced state of my pack was the main cause. Over time it deteriorated to greatly reduced capacity, 1/3 useable capacity from full before regen, longer very inefficient force regens, and reduced assist. Balancing the pack just from charging all the cells and discharging to zero without replacing sticks restored its health.

My discharge rate looked like a normal gradual hill. It's been great for 4 months now without a grid charge balancing. Driving from the first grid charge i had a ton of capacity. Once that wore off, my normal capacity improved a lot.

Now i can tell that my battery is running at reduced capacity from a good battery. However, It is behaving itself well. I'm using a good range of my useable capacity, and my regen efficiency is good. (my car never does the force regen where it deletes all your bars and regens to full.)

Long story short, you want the minimum difference of capacity from in sticks from highest to lowest. Also grid charging the whole pack regularly will negate force regens, improving mpg. Since you seem to be a knowledgeable diy guy, i'd suggest building a grid charger for less than $100 in parts.

[sheepdog 44]

Ok, just skimming this thread. If your just cycling to improve each stick, and then putting them all back in the pack, it will still be unballanced.

Secondly, if it's a 2003, don't you still have a warranty on the battery? Don't know about civics, but 1st gen Insight packs are warranteed 10 years, 1xx,000 something or other miles.

[microhybrid]

Originally Posted by sheepdog 44

Ok, just skimming this thread. If your just cycling to improve each stick, and then putting them all back in the pack, it will still be unballanced.

Secondly, if it's a 2003, don't you still have a warranty on the battery? Don't know about civics, but 1st gen Insight packs are warranteed 10 years, 1xx,000 something or other miles.

Balance is not only the capacity, but also the IR of each stick, it is the IR which indicates the balance of all sticks not the capacity.

[Formula413]

Update:

I took the pack out of the car again for more testing. This time I did a self discharge test of all the subpacks, charging them with the superbrain, recording their capacity, letting them sit for a week and discharging them and recording mAH returned. I was expecting to find a few subpacks with very high self discharge rates but this didn't prove to be the case. The capacity returned on discharge for each subpack after a one week rest was between 77%-84%, not an exceptionally wide spread to my eyes. Before I put the pack back in the car I charged each subpack again just to be certain they were all full and drove the car. It set P1449 before I even made it out of second gear.

So now that I've established that all subpacks have good capacity (>6,000mAH) and similar rates of self discharge, the only other potential issue I'm aware of would be that some subpacks bench test well but cannot handle the high discharge rates they are subjected to in the car. I read on another forum about another testing procedure which involves using a high current battery load tester to test the subpacks under loads similar to actual driving, and monitoring the voltage of each cell in the subpack to see which ones drop out. Is anyone here familiar with this test, or has anyone done this and had success? Here is the load tester that was used for this test:

500 Amp Carbon Pile Load Tester

[Formula413]

Bump

Anyone?

[retepsnikrep]

P1449 has several subcodes you need to find out which it is.

You need to get the equipment detailed in that thread on IC and test your sticks.

You could have a few dud sticks (if you are lucky) or you might find that the IR of all your sticks has increased and they can simply not cope with high IMA currents anymore, in which case all would need replacing. Nothing you can do about high IR.

If you confirm high IR on all sticks then you could consider my IMAC&C device for the HCH1 which has a battery protect mode stopping or reducing the ima requests to levels the battery can cope with. It's well documented on IC.

The best option would be to fix the pack of course.