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Hybrid TechnologyUnique topics related to the 2004 -2009 RX400H model hybrid drivetrain and other features/options found only on the RX400H. Please use the main forum for discussion about shared components with other second generation RX models.
Warning.. Don't freak out because your battery has aged.. It does not mean it has gone bad and you need a new one.
Battery degradation is the loss of ability to hold as much charge (capacity) than original.
Found these studies publised in 2010 interesting . Basically Idaho had tested the battery degradation by putting the vehicle through "160,000 mi of accelerated durability testing"
Info about the Traction battery (info from Dorman)
Three types
Lexus RX400h 2008 From 10/08 , Toyota Highlander 2010-09 Part numbers:OE G928048031, G951048032 Dorman 587-032
Lexus RX400h 2008 To 10/08 Toyota Highlander 2008 , Part numbers:OE G928048030, G951048030, G951048031 Dorman 587-031
Lexus RX400h 2007-06, Toyota Highlander 2007-06, Part numbers:OE G928048010, G951048010, G951048011 Dorman 587-030 Specifications (pulled from several sources -I am not certain)
Voltage: ~288v
Tyoe: Nickel Metal Hydride (NiMH)
Amperage Rating: 6.5 ah
Length: 43 In.
Width: 25 In.
Height: 7 In.
Weight: 152.1 lbs
15 battery blocks, 2 blades per block, so 30 blades (modules).
Blades are 9.6V modules connected in series.
240 Cells, Panasonic EV 1.2V
What I want to find out..
What is acceptable Voltage difference. (I think someone mention 1.2v in the GC forum)?
What is acceptable Battery Internal resistance?
What is acceptable Battery Temps?
Last edited by jooksing82; 08-23-18 at 12:32 PM.
Reason: adding more info
Here is the result of Dr.Prius. let me know what you think. 2008 RX400h with 140k. I will play around with it more to see what I can understand from it. When I held the brake and gas down (like the ISC reset) the charge rate was at 50 amps.
The Dr. Prius app has a battery test on there that you can pay for. $9 (not sure how many tests it would allow) I am still debating if it is worth it or not.
I correlated with the state of charge(SOC) to the battery monitor on the center console. Near depletion (purple bars) The App said the SOC was 40% and near full Charge was 67%. The battery temp ranged 98F to 108F. I will try to charge further after my battery cools down a little after parking.I recall charging by holding the brake and gas in drive should be done for a limited time only. i did it for 10-15 secs at a time. I can see the charge rate in the Dr.Prius when doing this, the rate is different when pressing the gas 30% vs 60%.
I'm not very knowledgeable about traction batteries, so have a question. What would one do with this information?
Assuming you found an amount of degradtion, or voltage difference across cells, is there anything an average user can do to improve this, or does it just tell you the state of things and let you know if and when the battery might be going bad and might need replacing?
I'm not very knowledgeable about traction batteries, so have a question. What would one do with this information?
Assuming you found an amount of degradtion, or voltage difference across cells, is there anything an average user can do to improve this, or does it just tell you the state of things and let you know if and when the battery might be going bad and might need replacing?
You might care to take a look at this short paper on hybrid systems diagnositics. The part about "Battery Failure Example ... Calling Multiple Witnesses to the Stand" might be helpful.
I had a "stable" good voltage and resistance between all cells, but nothing showed the "dying" cell within the right pack.
PS: DrPrius can do 2 tests to see battery condition and life expectancy.
DrPrius can do 2 tests to see battery condition and life expectancy.
What are those tests? How are the tests relevant to "battery condition and life expectancy". Please provide details. You seem to be quite outspoken about this subject.
Originally Posted by iMSQ
I had a "stable" good voltage and resistance between all cells, but nothing showed the "dying" cell within the right pack..
This doesn't mean "resistance and voltage are useless..." as you stated earlier, does it? If the resistance and/or cell voltage had been markedly different for one or more cells, it would suggest the battery was suffering in some regard.
Yes, perhaps if both the resistance and voltage were all uniform, it should not be taken as conclusive evidence that the battery is healthy.
What are those tests? How are the tests relevant to "battery condition and life expectancy". Please provide details. You seem to be quite outspoken about this subject.
1. Charging-discharging of battery (current capacity = "how long it will live")
2. "Load" test - battery testing at test-drive (looking for bad/weak cells)
Originally Posted by 2008RX400h
...
Yes, perhaps if both the resistance and voltage were all uniform, it should not be taken as conclusive evidence that the battery is healthy.
Yes, a good picture (of resistance and voltage) doesn't mean that battery is also good
I'm not very knowledgeable about traction batteries, so have a question. What would one do with this information?
Assuming you found an amount of degradtion, or voltage difference across cells, is there anything an average user can do to improve this, or does it just tell you the state of things and let you know if and when the battery might be going bad and might need replacing?
In reality, might just cause unnecessary worrying 😄. But I figure reporting condition and issues over time can help people see if there is a trend or not. It took a few years for people(and us) to figure out known issues with 400h (and other cars) which led to the inverter/ipm recall and extended warranty for the brake actulator.
For the most part just enjoy the vehicle and look out for issues. Some have sold the vehicle or found good/cheaper ways to fix it to keep it rolling.
Last edited by jooksing82; 12-30-22 at 08:19 AM.
Reason: Spelling
In reality, might just cause unnecessary worrying 😄. But I figure reporting condition and issues over time can help people see if there is a trend or not. It took a few years for people(and us) to figure out known issues with 400h (and other cars) which led to the inverter/ipm recall and extended warranty for the brake actulator.
For the most part just enjoy the vehicle and look out for issues. Some have sold the vehicle or found good/cheaper ways to fix it to keep it rolling.
i do miss my new car mileage ~26mpg, if i recall correctly..
The current avg is about 21mpg.. so about ~25% worse, which is in line with the research article you'd posted above.
Interesting, my RX400h 2008 has 280k miles and we are on original battery. Only info I have is the cell voltages are equal. No codes, but I do occasionally see the batteries deplete rapidly in summer with Airconditioning running and stand still traffic.
Interesting, my RX400h 2008 has 280k miles and we are on original battery. Only info I have is the cell voltages are equal. No codes, but I do occasionally see the batteries deplete rapidly in summer with Airconditioning running and stand still traffic.
I think that's pretty normal. Personally I don't give much thought to the traction battery, in the UK Lexus do a hybrid battery health check with each service, and warranty it for 15yrs. Beyond that you don't hear of many people whose batteries have failed, and there are now third parties who will refurbish batteries or replace individual cells at far less cost than a new battery. Actually, now I think about it, I don't hear of too many that suffer engine or transmission failure either compared to other manufacturers. Probably the biggest cause of expensive failure/damage would be poor maintenance, corrosion and accident damage.
Interesting, my RX400h 2008 has 280k miles and we are on original battery. Only info I have is the cell voltages are equal. No codes, but I do occasionally see the batteries deplete rapidly in summer with Airconditioning running and stand still traffic.
I've got 200k on my 2008 RX400h and this spring (2023) the HV battery was showing obvious signs of EoL.
I wound up replacing it with a new one and... WOW, I've got my hybrid back!!!
Interested readers will find my multiple posts in this thread:
08-16-18, 08:49 AM
Battery Degradation- Traction Battery
