Battery Modules Showing 8.4v - Too High

Your best bet would be to get the codes read when it throws the triangle. You will most likely have a "Block x becomes weak" code P3011 through P3024. One (or more) of the 14 blocks has a module failing (or failed). When you continue to drive it, the engine will do some significant rpm, and will have a hard time going up even small upgrades, but it will overcharge the heck out of the battery, due to it sensing the weak block. I've been through that plenty of times. Most likely, this is whats causing your battery to overcharge. If you've already removed the battery, let it sit over night and check the voltages again. Most likely, one or more will be significantly different from the others. Most will probably be in the 7.8 range and one or two will be around 7.0 to 7.2 or lower.

 

Hehe, I had been looking for a new NZ New Gen II and probably glanced at that one. lol. I have just bought a nice 2007 with 175,xxx km on the clock.

Those voltages are not too high, each module could be as high as 8.44 V fully charged.

Where in Welly are you? I have a code reader and would be happy to give you a hand to read the codes and talk over battery ideas with you. Depending on what the codes say, you maybe could consider reconditioning.

 

Yeah, nominal voltage of a block (2 modules) is 14.4 V, but I have seen blocks reaching 19+ V under force charge.

There are a few Kiwis on PC, mostly in Auckland. If you'd like, I'd be happy to at least chat with you about your situation, so PM by using the "Start a Conversation" link on the left under my avatar if you want to trade details. I'm over the other side by the airport.

[EDIT]

Meant to add:

Depending on what code reader they used it may not have seen all codes, but if you can post what they gave you, it may help.

 

That is a good menagerie of codes, but the P0A80 would be the one of interest.

Does your combination meter intermittently go out?

 

A battery pack should never be "fully" charged under normal operating conditions while installed in the car. The normal control range of the battery pack, when the battery is in working condition and installed in the car is between ~65% and ~43% SOC. That range is merely based on my observations while driving and monitoring many different battery packs. There are rare circumstances that can cause high charges like extended downhill grades.

Are the control ranges different in NZ, or does this model use a different style battery? If it's the same as a US Gen 2, and his voltages are 8.3 -8.4, then the modules are at a MUCH higher state of charge than they should be, hence "being over charged". I'm not saying they are physically overcharged past their maximum 100% SOC capacity, I'm saying they are well beyond the car's normal control range. This is a pretty "typical" type occurrence based on his symptoms as I expressed in my previous post.

Hopefully, you guys can get together and get the car sorted out.

 

Actually yes, that is correct. However, when testing HV batteries in my recent search for a new Prius, I have seen blocks go to nearly 20 V on the way to 80% SoC when I was force charging and then dropped back quite quickly to 17.5 -17 V as it arrived at 80%.

This car was a 2009 that was repossessed and at auction. Here are the graphs I did of that test:

No, not as far as I know, should be the same – same NiMH battery. I agree with what you say should be seen in a healthy battery.

Unfortunately I do not have at my disposal any newish batteries, so all I have been able to test are relatively old batteries and so that is the data I have personally seen and I am still trying to work out what to look for in the data I have collected.

Even my own battery, which I consider to be working well, gets to the late 18 V range when I force charge. I'm not making any judgement call on whether what I have seen is good, bad or otherwise. Merely commenting on what I have seen firsthand.

But yeah, hope we can get together and sort it.

 

I think you might have a battery issue here. Y not allow the battery to rest some bit, then test their nominal voltages to determine which is(are) the culprit.

 

Dolj,

Why do you force charge your battery to the 80+% range? Wouldn't that potentially cause some problems with individual modules that may not have the capacity to absorb that much energy?

 

It is the process outlined in the How to test HV battery state of health on your Gen 2 (answer) thread started by S Keith. I never thought about it, but I figure if it were a problem the battery control ECU would not allow it and/or throw codes.

Just found it interesting that all the cars I have tested so far have allowed the voltage to go high, one just over 20 V. Another interesting thing, I record the 3 temp sensors and although I haven't graphed it, the highest was TB1 and only reached 23.8 ºC (74.8 ºF)

Another car, on the hand, the temp went up to ~40 ºC (104 ºF) during the charges. Neither car activated the HV battery cooling fan to an audible level.

I haven't been able to draw any conclusions, just collecting data at the moment.

 

I can guarantee that you will not get a NEW battery for $950.

Instead you will get a battery that someone else swapped random "good" modules into.... Similar to what would happen if you did it on your own. (Remember, a "good" module doesn't mean it matches the characteristics of the rest of the pack.)

You could try to get an untouched one out of the junkyard I suppose. Maybe out of a Gen 3, remove the modules and them put them into your case.

 

sure, or put the whole thing on eBay.