I was in the process of connecting a grid charger to my car. I checked the voltage on the hybrid battery once it was disconnected from the IPU and it read zero volts with the hybrid battery breaker switch on.

This was strange because my two 2005 HAH have voltage when disconnected and the breaker is on.

After removing the battery from the car, I removed the junction board and checked each cell pair. I found two circuits made of 5 and 6 pairs.

The first pair totaled 67.9V (14.6, 13.1, 13.7, 13.4 and 12.9V)
The second pair totaled 81.9V (13.3, 13.4, 15.0, 13.5, 12.9V, 13.6)

I was hoping to use a whole unit grid charger to charge and discharge the battery like I did with my hybrid but cannot seem to get continuity at the hybrid batteries terminals like I could with the Accord batteries.

The junction unit or the battery head contains only a few parts
- Actuator
- Current sensor
- 40 Ohm resistor - tested good
- 100A fuse - tested good
- convergence of temp sensors

So, are my low voltages causing the disconnected battery to provide voltage at the head terminal? Or does it have to do with something else.

Pretty stumped - any help is appreciated.

 

Are you following the installation instructions for your grid charger?

The condition you describe is normal.

The only time the HCH2 has voltage at the main terminals is when the ignition is on, the computer confirms the pack is okay to connect to the car, and the 12V relay is energized OR, the car is running with the IMA pack isolated, and the voltage at the terminals will correlate to changes in rpm as you're getting the direct output of the IMA motor.

This behavior is identical to the G1 Insight and the HCH1. I think you're mistaken about the HAH, but I've never seen an HAH pack. However, every other NiMH hybrid battery that has some sort of safety switch (every Toyota hybrid ever made, Ford escape hybrid), breaker, etc., does NOT have voltage at the main terminal unless the car is on AND the associated relays are energized.

Refer to the hybrid automotive website installation instructions for the grid charger attach points.

I'm sorry to say, but your pairs are a **** show (does not qualify for your subject "cells are good"). Furthermore, you can check those voltages by probing the back of the orange plug without any disassembly or even removing the plug from the BCM:

https://www.dropbox.com/s/l4sj188ldw...Check.png?dl=0

A moderately healthy battery will have resting tap voltages at less than 0.2V from min to max. A truly healthy pack is typically less than 0.1V from min to max.

Good luck,

Steve

 

Hi Steve,

Thank you for your response. I came to the same conclusion as you mentioned that the connection was incorrect between the battery & the HCH
II grid charger. The positive grid charger wire does connect to the main positive terminal into the hybrid battery. However, the negative is supposed to go to the terminal on the actuator. Once I resituated the negative cable from the main terminal to the actuator., I could see the total voltage of the battery on my grid charger display. This was different from the two HAH batteries I have reconditioned. Once you switch their breaker on, there is a voltage on the main terminal (the one that connects with heavy gauge orange wires to the control module.

When I said the individual stocks were good, I meant that they were not at 0 volts and had some voltage. Albeit, poorly balanced. Do you know what the voltage should be per stick pair on a well balanced HCH II battery pack.

The good thing is I got to open up the pack to see how badly balanced the sticks were. I have finally been grid charging & discharging and am doing a final charge. I am hoping the pack is more balanced. So, per the link you provided, I should be able to probe the large orange connector for stick pair voltages without pulling the pack and removing the battery head,

Based on voltages on the unbalanced pack that I provided, would you think that charging and discarging will fix the battery or are the voltages seen, too low?

is it possible to load test a stick pair through the large orange IP connector with the pin outs you provided the link for? Or are the wires too thin for such a load?

Is is it possible to replace the poor cells after identifying them by load testing?

Thanks so much

Ash

 

The 06-08 HCH battery is the 2nd worst HV battery ever made (09-11 HCH is the worst). The likelihood of a long term fix is zero. With a little luck, you will need grid charging every few months with discharging MAYBE once a year (only discharge when grid charging doesn't yield the desired results). The dramatically terrible subpack readings support the low likelihood of a fix. Most sticks are likely suffering from massive self-discharge. Cycling should help, but there is a very good possibility at least one cell in the pack has failed outright. Your efforts may yield nothing more than a days or a week's worth of trouble-free operation if that's the case.

The connector wires can't support significant current.

Per my first response:

"A moderately healthy battery will have resting tap voltages at less than 0.2V from min to max. A truly healthy pack is typically less than 0.1V from min to max."

Replacing cells requires precision cutting, grinding and spot welding. It has never been demonstrated to be viable. Entire 12 cell subpacks can be replaced, but as it's the second worst battery ever made, locating suitable replacements is unlikely.

EDIT: I have confirmed you are indeed correct about the HAH battery. I stand corrected. It is safe to say that this property is unique to the HAH and differs from all other Honda IMA vehicles and all Toyota and GM hybrids.

 

EDIT: I have confirmed you are indeed correct about the HAH battery. I stand corrected. It is safe to say that this property is unique to the HAH and differs from all other Honda IMA vehicles and all Toyota and GM hybrids.[/QUOTE]

Thanks for confirming the HAH configuration. I have a spare HAH pack that I picked up back in April from a salvage yard. I conditioned it with my grid charger and discharger a few weeks ago. It has a styrofoam head on it which I popped off last night and measured the stick pair voltages. It was amazing as each stick pair measured exactly 15.8V each, even after sitting on my bench for a month. No variance whatsoever = healthy battery.

The battery has an SB2 marking on it which is not found on my original HAH battery that I grid charged. Not sure what that means.

Moreover, the original battery in my HAH gave me good mileage right after the first grid charge but since has not, especially when I first start driving it. It fell from the teens to single digits but then gets a bit better when I drive but not to a healthy hybrid level.

i am planning to swap out batteries when I get a chance. Is there any additional programming needed once a new pack is put in? I have the IPU that the battery on my bench came with. Should that be swapped out as well to avoid the need for further programming? I was curious as to what exactly gets programmed when folks on threads refer to having a need to have a dealer reprogram your car when batteries are swapped?

 

Measurements like that are typical of a well-balanced pack with no failed or marginal cells.

I don't know the specifics of the battery codes or programming requirements. You may want to replace the computer that came with it as well just to be prudent.