2007 HCH Battery replacement

[msantimanzano]

I was able to get the following information for myself today.

The Accord battery has 10 modules that are connected in series. Each module has 12 1.2 volt cells. Total battery voltage is nominal 144 volts, and the maximum capacity is 6.0 Ah

Hope this information will somehow be helpful to me along the way.

I have a question though, isn't charging the batteries at a high amp level like 5 amps, going to risk overheating some of the batteries too fast and damage them? I thought (though likely thought wrong) that charging the batteries at a low setting was better and safer?

[CT2007HCH]

Yes charging at high currents is a bit dangerous that is why you need a computer controller charger that keeps track of charge, time, voltage and temperature.

Maximum fast charge for a NiMh is 1C. That is 1 x the capacity. So for yours that would be 6A. Mine were 6.5A but my charger maxed at 5A. I had a battery get very hot at 5A when I set my charge limit to 7500mah. So to keep it safe I went to 3A charge, max 6500mah input charge, and added a fan to the cells while charging.

Safe charging for NiMh is 0.1C so 600ma for your cells. This should take about 10 hours. This is considered normal.

Trickle charge is 0.05C.

A grid charger will charge all the cells at once and runs at ~350ma.

For comparison. The civic pack contains 11 pairs of 12 cells each at 6.5Ah.

Here is the write up I used as my starting point. There are some details left out and no pictures but it was very helpful.

Sucessfully Reconditioning an IMA Battery Pack - GreenHybrid - Hybrid Cars

[msantimanzano]

At what point in temperature should I immediately stop charging the pack?


I was looking at using something like this, to automatically shut off my charger when the temperature hits a specific point.

Johnson Digital Temperature Controller: Programmable Household Thermostats: Amazon.com: Home Improvement

Here is the manual:

http://cgproducts.johnsoncontrols.co...PDF/125188.PDF

[Cobb]

The insightcentral guys advise powering up the original blower on the bench and once nearly full use .350 ma to balance the cells. You will notice the voltage go up and down as they real 100% capacity. Once the voltage stabilizes after several 15 minute checks its considered balanced.

Plan b is to cycle the sticks or modules with a hobby charger and use the built in delta V feature and note the capacity when a cycle is done. 3-5 cycles is all it takes to help bad sticks.

You should keep the sticks cool, it isnt a contest to see how hot you can get them.

[CT2007HCH]

I did manage to over heat 1 cell in a pack. I did some research and the highest temp I could find that was acceptable is 60C or 140F. In Texas the inside of the car can get to 120 so I'm not sure if that is a good number.

The problem I ran into was that I was charging my worst cells at 5A with a 7500mah limit with no fan. I looked when they were at about 7000mah and I checked the cells with an IR thermometer. 5 of the cells were 120F and 1 was 140F. In about 5 minutes it went to 160F and I aborted.

At that point I changed to 3A charge, 6500mah limit and added the fan.

So the problem with a single point temp sensor is you may not be on the cell that needs it.

Here is a really good site that talks about NiMh charging in general.

Technical Tips for NiCd and NiMH Battery Pack Users — CamLight Systems

[CT2007HCH]

I added descriptions to my pictures.

Honda Civic Hybrid 2007 Batteries - Imgur

[Cobb]

Yeah, they have low temperatures. Many states with hot summers have reduced warranty on the batteries like Arizona, NV and a few others.

Sounds like that was the bad cell with higher internal resistance. The addition of an ir temp gun helps you to single out the bad cell within a stick as its usually a cell, but since they are welded together it makes it a bad unit.

[MaxxVolts]

Yes this is our video covering how to install the maxx-volts.com grid charging system for 2003-2011 Honda Civic Hybrid. Typically people purchase our systems to fix their P0A7F battery deterioration codes or balance their pack and get rid of any number of the following codes. P1447 P1449 P1600 P07AF P1433 on their Honda Insight 2000-2006, Honda Accord Hybrid 2005-2007. For the Prius, we have folks purchase our charging system to get rid of codes P0A80 P3006 P3017 P3018 so they can restore their MPG and pass emissions / smog testing. If anyone needs any more information about our video posted above or our charging systems, send us an email or PM.

Originally Posted by CT2007HCH

Here is the video that shows how to remove the pack in the civic.

[geego]

Could anyone help me with the settings to condition my 2006 hch sticks? I have them out and am trying to figure out how to set my imax B6 (looks like a bogus one) to do a charge/discharge cycle