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-   -   Civic hybrid 1st gen IMA won't recognize new battery (

Newton 05-14-2015 10:00 PM

Civic hybrid 1st gen IMA won't recognize new battery
I got a used pack from the salvage yard since mine wouldn't hold a charge even with the grid charger. I charged the "new" one with the grid charger, held full voltage with no load so I installed it.

Even after pulling fuses and disconnecting the 12v battery to try and reset the system it still refuses to see the fully charged pack.

It did however manage to start itself a few times off the IMA system but not anymore.

Only thing I can think of is maybe what looks like a relay isn't connecting the pack to the system because the bus bars that are always live when the switch is on shows fully charged voltage and I'm reading 60 to over 200v at the main terminals as engine rpm goes from 1500-3500.

I got lucky and managed to find the new pack without a core charge so I could try swapping components. I'm trying to get this running by Monday so any advice would be greatly appreciated, thanks.

Newton 05-25-2015 06:24 PM

I figured it out along with the details on testing the sensor leads from the connectors. Turned out the circuit that runs through the pack along each battery was the problem. The only thing that I can assume about its purpose is to let the computer know if a battery exploded or possibly overheated enough to melt the metal strip shrink-wrapped against the sticks. Should be about 20ohms fyi.

Here's the original pack opened up:
And here's the new pack:

The problem was with the wire wrapped in red plastic that can be seen cut in the first.
My car doesn't like that circuit apparently.

I would be interested if anybody has any ideas why someone would disable what I believe to be a security feature and why it actually needs it that way.

I also figured out how to test the values coming from the three thermocouplers inside the pack from the outside, if anyone's interested I can label the picture I took of the connector.

I narrowed down the pin on the connector for each of the twelve (I'm assuming since their resistance did change with finger temp) thermocouplers on the end plate but you have to have the top off to test those since they terminate on the stick lug next to them.

S Keith 05-25-2015 10:07 PM

Honda stopped using the PTC strips sometime around 2003-2004. The wire cut in the PTC circuit is part of the technical bulletin that goes along with an ECU flash for pack replacement.

The PTC strips were pure paranoia. They protect against a massive meltdown, which has never occurred. The 3X thermocouples provide sufficient protection.

Baltothewolf 05-26-2015 01:31 AM

Bingo kieth. Honda wasn't sure how this new tech was going to react to people living in the hotter climates like Death Valley, Phoenix Arizona, Las Vegas, etc etc. They went overboard with the security so they made sure nobody was killed. They removed it once it became clear it was pointless and a waste of money.

Newton 05-26-2015 01:21 PM

That's good to know it wasn't some hack job! If they've flashed the ECU does that also mean they did the software update to reduce the IMA power or did they only do that to the second generation?

S Keith 05-26-2015 02:18 PM

HCH1 and HCH2 use completely different ECUs/Programs. The "patch" that tweaks the IMA effectiveness only applies to the HCH2. There may or may not be something similar for the HCH1, but I don't know about it.

HCH2 IMA system has 50% more motive power, 10% more total batteries/voltage with 15% less capacity and improved internal resistance. The increase in total motor output taxed the battery system more than anticipated even with the battery pack improvements. The end results were abnormally high battery pack failure and altering the ECU (technically the BCM, I think) programming to be less demanding of the battery for most routine driving. Heavy acceleration will still get the full 20hp of the HCH2 IMA motor provided the battery can deliver it, but for less time due to the more conservative battery management.

hybridregret 08-29-2015 12:59 PM

I was going to start a new thread, but this topic is so close to mine that I'm going to start by asking here.

2005 Honda Civic Hybrid owner. After a thorough battery reconditioning and a final top off charge on every stick, I've made it to the exciting and worrisome stage of reassembly. I let it sit for 2 weeks to let the voltage stabilize after the final top off charge, installed it, and my gauge cluster is showing an empty battery, while I'm measuring 159.8 VDC at the battery (8V/stick).

Is the computer just not liking the battery because the voltage is higher than the factory parameters allow for? I put a "full" charge into the battery before pulling it out for the reconditioning process, and each stick measured right at 7.80V at the time of disassembly (156.0 VDC for the pack). This makes me assume that perhaps the computer says the maximum voltage is 156. Do I simply need to drain this thing down so my output is not above that?

hybridregret 08-29-2015 01:45 PM

Because I imagine an investigation into the details of my refurbishment will be precipitated by my first post, here is a little info on my process.

I topped off the battery in car, by using the little trickle charge the IMA at or above 3k rpms trick immediately prior to disassembly, to capture what data I could about what the car considers to be a full charge.

It came out right at 156 VDC for the assembly, and each stick measured right at 7.80 VDC upon disassembly.

I then documented the discharge mAh of each stick during a 10A drain to .8V/cell. The values were pretty pathetic, ranging from 193 to 2748 mAh per stick. A trio or better of 10A-discharge/2A-charge cycles per stick netted me an average charge input of 6642 mAh per stick, with the maximum variation of only 0.04% between sticks.

I monitored and documented the voltage decline over time before cycling each stick again to verify holding capacity. After about 2 weeks, each stick was in the range of 7.95 to 8.00 VDC, and they all discharged right around 5000 mAh. A pretty good looking bunch if I say so myself.

As my final step in the refurbishment process, I quickly went through the entire lot twice in a staggered fashion doing a reflex (996 milliseconds charge @4A, 4 milliseconds @10-16A discharge, every second) top off charge to ensure an even voltage profile across the entire pack. This left the assembly at nearly 170 VDC (>8.3V/stick). I felt that letting it normalize over 2 weeks to <160V (<8V/stick would be smart, as I felt like >20V over the 144V nominal was likely to piss of the battery management computer.

My suspicion at this point is that I have pissed it off, and I\'m going to have to load the battery to get it below 156V.

Sorry for the novel, but the forums I regular will publicly hang you if they don\'t get the full scoop prior to a request for advise.

vskid3 08-29-2015 02:31 PM

Will the car start? The car might just need to relearn what the SOC is by driving it a bit.

hybridregret 08-29-2015 03:42 PM

I was planning on giving it a spin straight to an emissions inspection station, but when the gauge cluster didn\'t agree with what I know about the battery, I stopped there. I\'ll go plug everything back in and give it a shot this afternoon. If it starts I\'ll try to drive it and load the battery a little bit.

Are the P14XX and P1600 codes somrthing I will need to pay someone with a scan tool to reset now that she\'s got a box full of happy cells?

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