2007 Gs450h Hybrid Battery Cell Replacement For $50.

[GS450hPurr]

This helps.  I am going to invest in the charger you mentioned.  I have purposely NOT started the module assessment or replacement yet until confirming this bit of informations because I did not want to make a situation worse or more expensive.  I will do the diagnosis and then decide the most efficient means to replacing them, with the "AH" (Amp Hours) in mind.  I currently have my Hybrid Battery Pack removed and sitting in the garage awaiting my next move. 

And let me warn ANYONE who attempts this repair just how heavy these Battery packs are.  I am strong but this Battery was very heavy to move with sharp machined metal edges to grab hold of.  You better man up, cover the body of your car, and lift up and away and be mindful of your posture as not to strain your back or otherwise.  It is heavy!!!!

 

[GS450hPurr]

2 hours ago, Britprius said:

The best chargers to use are the Imax B6 mini chargers. These are made for charging, and restoring model car, and plane Nimh batteries.

They can be programmed to charge at any given rate "up to 5 amps" and cut off at a predetermined voltage or auto cut off when the battery "in the case of Lexus modules 6 cells" is fully charged. The charger self adjusts to the number of cells. They can also be set to charge  lithium batteries, or lead acid batteries. The chargers can also be set to cycle the batteries "fully charge then discharge the batteries" up to 5 times automatically. This can rejuvenate NiMh batteries.

Ordinary 12 volt chargers if left connected to NiMh batteries will overheat the batteries as with this type of chemistry once a cell is charged all energy put in after this point produces heat drying out the cell. The charger must turn off once the cells are charged. 

If fitting one new module in a battery it must be charged or discharged to the same voltage as the others in the battery. Failure to do this will bring trouble at a later point.

John

Hey John-

 

First, thank you solving this mystery.  I am trying to demystify this time consuming repair for those of us who are qualified and not afraid to take on this repair, however it is imperatively important that we all follow proven methods of safety for ourselves and the proper mechanics of the batteries and the respective modules within.  I for one am not and expert at understanding the Battery chemistries so that was a weak area for me and I didn't want to proceed without the right knowledge.

For anyone else out there following and resorting to this post NOTE that I have found a few areas in my progress to make this original repair post a little easier to follow.  I have managed to overcome a few methods I will later add into this process which will make the repair less burdensome I think.  For one, the thing I found to be a much better method was actually removing the rear bottom portion of the leather bench seats, setting them aside outside the vehicle in a safe place to avoid rips, tears, or punctures, and then for the upper portion of the rear seats just loosening the bolts securing them below where the seat-belt anchors are and then simply leaning them forward with the seat-belts still running through the plastic guides on the upper corners of the upper seat cushions near the windows (2 of those) and then you don't have to actually take the upper seats out but ultimately allow yourself more room to get a good firm grip on your ratchet in order to remove the (3) hybrid anchor bolts behind the seats, at the rear of the boot/trunk, and beyond the fireproof fabric without tearing it.  I also didn't want to break the center arm rest plastic divider that only pops forward about 6 inches and is connected....pry to far and then you'll end up breaking that.  $$$   Trust me, save yourself some heart ache and remove the lower portion of the rear seats and lean the upper seats forward after taking out the two bolts for each side.  Keep in mind the rear seats are a total of (2) pieces:  The Upper Portion and the Lower Portion.

One bonus to this is you'll also take a moment to find any loose pocket change which can rattle in time and recover any of your kids missing Legos,  I also reaffirmed that my seat-belt anchors were all nice and snug for a safety check.  One seat-belt anchor was in fact loose.

[GS450hPurr]

2 hours ago, Britprius said:

Refurbishing the high voltage batteries is possible, but do not fall into the trap of thinking, buy a replacement from Ebay, throw it in, and all will be well. There is much more to it than this if reliability is required.

The battery consists of 240 cells in a series chain. The current if being charged or discharged passes through every cell, and as with any chain one weak link "or cell" will brake the chain.

Over time after many thousands of charges and discharges some cells will have less charge than others. This is called being "out of balance". In the most severe case when the battery is under load "discharge" a low charged cell can be completely discharged, and will then be reverse charged as the load continues on the rest of the battery. This destroys the cell requiring the module that cell is in to be replaced.

The cells when new have a capacity of 6.5 AH "amp hours". As the cells age this figure goes down. When buying second hand modules from Ebay you have know idea of the capacity remaining in them. The voltage measured will still be the same, but the capacity may be 6.5 AH or may be only 2 AH you have no way of telling. The charger named in my previous post will check the actual capacity.

All the modules in your battery "40" should be checked for capacity, and all should be as equal as possible. None should be below 4 AH and ideally all should be above 5AH 

To do this work properly takes lots of time, but there is no short cut to reliability.

John.

John-

I looked into and ordered myself one of the Imax B6 mini chargers you recommended.  You're right.  This is the one to use for the modules in our vehicles.  I am planning on checking each module for not only Voltage but AH capacity on all of the modules and replace accordingly.  Once I have all the replacements above 4 AH I am then going to condition every single module by setting them to fully discharge and recharge cycle on the Imax B6.  Then I am going to enure they are all fully recharged at the same voltage reading prior to reinstalling and reassembling.

Pictures coming soon...

[Britprius]

1 hour ago, GS450hPurr said:

John-

I looked into and ordered myself one of the Imax B6 mini chargers you recommended.  You're right.  This is the one to use for the modules in our vehicles.  I am planning on checking each module for not only Voltage but AH capacity on all of the modules and replace accordingly.  Once I have all the replacements above 4 AH I am then going to condition every single module by setting them to fully discharge and recharge cycle on the Imax B6.  Then I am going to enure they are all fully recharged at the same voltage reading prior to reinstalling and reassembling.

Pictures coming soon...

Once all of the modules have been cycled, and assessed to get them all to the same voltage connect them all in parallel for a few hours so that you have one big 7.2 volt nominal Battery. "actual voltage will be higher than this." This way higher, and lower voltage module will charge and discharge each other until they are all at exactly the same voltage. After this you can connect the modules in series knowing that all modules have the same voltage and charge level.

This work cannot be rushed to complete properly. It is time consuming. Some years ago I bought a job lot (30) of the chargers in an auction for little more than the price of one, and this allowed me to rebuild Prius batteries with 28 modules in three days. I sold the chargers after I had finished with them.

Low capacity modules can sometimes be reclaimed by re-hydrating them "putting back lost electrolyte into dried out cells. I will not go into the process here"

John. 

[GS450hPurr]

UPDATE:

I managed to get all 40 modules tested.  Here's what I got:

All cells tested 7.8v except #21 was a little low at 7.7v and the culprit appears to be #25 which tested at 6.5v!  So I'm only going to replace the 6.5v culprit.  I'm starting to wonder why only 1 cell would have caused the entire Battery to fail.  I of course got the check engine light, the codes, the gas engine coming on more, and then it got to the point where the cooling fan stayed on and then the car completely lost power while driving a couple times.  I was under the impression these cars would continue to drive on the Gas Engine just fine.

 

[Britprius]

On 2/23/2017 at 1:20 AM, GS450hPurr said:

UPDATE:

I managed to get all 40 modules tested.  Here's what I got:

All cells tested 7.8v except #21 was a little low at 7.7v and the culprit appears to be #25 which tested at 6.5v!  So I'm only going to replace the 6.5v culprit.  I'm starting to wonder why only 1 cell would have caused the entire battery to fail.  I of course got the check engine light, the codes, the gas engine coming on more, and then it got to the point where the cooling fan stayed on and then the car completely lost power while driving a couple times.  I was under the impression these cars would continue to drive on the Gas Engine just fine.

 

Did you check the modules under load. Off load voltages are virtually meaningless. Although I agree you have one dead cell in module 25. The voltage you are measuring is for 6 cells (a module) 7.8 volts. One cell if you could get to the connections is around 1.2 volts.

To test on load use a car dual filament headlamp bulb, and using both filaments wired across the volt meter probes test for voltages. The bulb will put a load of near 10 amps on the modules each time you take a reading.

As I tried to explain in my previous post all 240 cells (40 modules of 6 cells) are in series. Any single weak cell effectively stops the system working. Bad cells have a high internal resistance, but still have to pass the high current required to run the 140 KW electric motor. This causes the bad cell to heat up rapidly often destroying other cells close to it. 

The system checks every pair of modules (called a block) for voltage of around 14.4 volts. Then checks each block against all the others under load. Any voltage discrepancy over 0.3 volts between blocks for a given time issues a fault code for the low block, and the car goes into limp mode. A good block (2 modules) has a resistance of around 24 milli ohms

John

[GS450hPurr]

Hey John-

So I got the IMAX B6 Mini charger in over the weekend and started playing with some of the features.  I did some reading up on NiMh batteries and from what I seemed to read up on these batteries don't tend to have memory like some other kinds.  I was also making sure there wasn't a minimum discharge rate.  I have a few questions:

1. The IMAX charger has some options for the discharge/recharge settings and so I wasn't sure... is it better to conduct the discharge/recharge cycles to the lowest Amp setting or does it really matter?  I figured the slowest discharge and recharge setting was better but I'd rather speed things up and increase the Amp rate and get the reconditioning along quicker.  Not sure here so the first module is set low with Cut off at 7.9v.  I also set it to cycle 5 times - is it necessary to cycle, and I know the complete cycling is good but is it necessary to set it to 5 times for each module?  If the ideal here is the higher the number of cycles the better then I am fine with doing the cycle 5 times.  I just wanted to know your thoughts on making this endeavor the most efficient for the time invested in reconditioning the modules with the right settings in mind.
2. I know the modules are standard at 7.2v comprising of 6 cells at 1.2v each.  So if the IMAX automatically knows when these NiMh modules are fully charged what should be the target voltage be for the cutoff upon recharging when I leave them to cycle?

[GS450hPurr]

Here are some helpful update pictures and feedback below for anyone out there...

The key used to remove the two (2) orange voltage safety pins (see picture of below).  I got miffed at this step and another member chimed in above to help.  I thought I'd show a picture to help others.  The key on the fuse panel is used to fit the male/female notches and turn the pins.  This ensures you are now entering the main voltage hot zone with the fuse in fact removed.  Nice thought out safety feature in my opinion by Lexus.

The blue circles above show one of the orange voltage safety pins you must use the fuse with the built in key to remove shown in the first picture above that I circled.  Wait and unlock this orange pin when you get the Battery removed from the trunk.  The secon blue circle above just shows one of the 3 rear mounting bolts you'll need to access in order to uninstall/install the hybrid Battery pack.  ***Another tip would be to completely unsecure and lean the seats forward to have better access through the fireproof material into the trunk space.

Slide the hybrid Battery pack carefully forward onto a cardboard box to avoid unnecessary scratches inside the trunk area.

I recommend a lamp with a bendable neck or shop light you can angle for good lighting to see while you work inside the trunk space.

These are heavier than they look.  Wear gloves, get a friend to help you and stay clear of the paint job or you'll be spending more money going to the body shop next on your list or repairs.  I was strong enough to lift it and move it but it was awkwardly large to handle given the strain.  The sharp edges of the machined metal makes it a must to wear gloves while moving. I cut my hands a couple of times.

Number your modules 1-40 and test each module.  I circled the obvious bad one I had in blue above.  It was #25 on my series.  It tested in at 6.5v without load.  It will be replaced.

 

 

 

 

 

 

 

 

 

 

 

 

[Britprius]

Cycle the modules twice saving the data, and starting with a charge. This will show the initial capacity and on the second cycle any improvement. If after the second cycle you are at or near 6000 mah (6000 milli amp hours = 6 amp hours) do not cycle again unless you wish to see if any more capacity can be recovered, but you will need to do a charge only cycle. Know harm is done with more cycles, but as you say it takes more time, and is not worthwhile unless reasonable capacity gains are made.  If lower than say 5500 mah it may be worth trying another cycle to see if more capacity can be regained.

Set the charger to auto cut off this will take the modules up to around 9 volts (fully charged cells are around 1.5 volts X 6 = 9 volts) Set discharge voltage to 0.9 volts per cell 5.4 volts for the modules this is a complete discharge of NiMh cells

Charge, and discharge at maximum current the charger will allow. Setting 5 amps the charger will probably scale that figure back as it can only handle a given wattage " cannot remember what that figure was. The Battery in use passes as high as 100 amps so 5 amps is not a problem. A cooling fan blowing over the modules is helpful.

John. 

[Britprius]

The principle involved in the above is that over time the cells in the Battery become unevenly charged. Some will have a low charge compared with others that will have a higher level of charge.

By charging the module till the cells with a high level of charge are 100% charged you then continue to charge the module. Any full cells will give off the excess charge as heat any lower charge level cells will continue to charge until they to are fully charged thus balancing the charge level of all the cells in that module.

John

[GS450hPurr]

Hey John-

I currently have the IMAX cycle set to charge first then discharge 5 times so I may go amend the process to your above post.  I went ahead and set the DISCH/CHARGE to maximum Amp to save time since it doesn't harm them or affect quality.  I have the IMAX Discharge set to the lowest Discharge option of 0.1v and the Charge set to 7.9v.  I guess I figured it would auto charge on cycle setting but maybe not.  I'll look again.  I think on the auto-charge setting it will auto max charge, but again, I'm kinda getting to know the IMAX and its settings some.  There is also a separate setting for "Re-Peak" which is what it sounded like you were referring to in the above post where finding more room for peak capacity on recharge.

Since I am cycling them all what then should be my final target charge for all modules upon completion?  I was going with 7.9v and then hooking them all up in their series to let them "even out" prior to reinstall.  Of course that'll be a week out from now since I'm just now getting off the runway with the reconditioning phase.

[Britprius]

A figure of around 8 volts per module is reasonable for the final rebuild. The charge level should be set to auto for the charging cycle process that will take the module to around 9 volts, and discharge to 5.4 volts. Although going lower than this can be beneficial it also has it's danger of reverse charging a weak cell in a module especially on the first cycle.

The charger auto cuts out by measuring a tiny fall in voltage, and then a rise as it reaches full charge. This is called the knee or peak a reference to the shape of the charging graph curve.

John

[hybridbatterysolutions]

Assuming you have sorted the safety seal issue now, if I can help just message me & i will see what i can do for you.

I have to be a bit careful as there are a lot of dodgy people out there who want to suck my knowledge, there is a foreign chap out there now in GB who was a customer of mine who is now going round supposedly repairing Hybrid Batteries cheaply - the thing is I didn't tell or show him everything so he is only doing half a job & does not know the proper safety precautions he should take either - needless to say when people have problems afterwards he is 'unavailable'??? and they end up coming to me. I have to say it makes me very sad & angry.

You might say its sour grapes but this guy is doing nothing for the reputation of the very few proper decent hard working technical independents here

Please be careful & research lots before going further.

Regards

Richard

[GS450hPurr]

Got all the modules cycled.  TAKES FOREVER - even running around the clock.  I was doing 1 at a time, but after the first ten modules I had to break down and get a Venom dual charger for the task.  Now I am keying in on making sure I balance the charges evenly across all 40, then planning to put them all back together and let them "even out" in series.  I did remove all of the copper bus bars to do a light sanding job with an electric sander so they're all nice and clean again.  Planning on putting them all back together with a coating of di-electric grease.

The one bad module I flagged and replaced, I did run through a few CHG/DCHG cycles for the fun of it to see what would happen and it still wants to hang out around 6.8v (a .3v improvement from the original reading of 6.5v when I first assessed all 40 voltages a month ago).

Tomorrow I should finally be reinstalling and firing the 450h back up again.  I'll post more and followup with results!

[Farqui]

Phew, what a chore but well done for getting on with it.

[hban398]

Hi all, been following this thread for a while since I've got a 2007 GS450H with the check hybrid light on.  I'm in the states but this forum has been very helpful.  Recently my car stalled so I knew the hybrid Battery needed attention.  So I decided to change out the bad cell.  I found 1 cell at 6.6 so I knew that was the one having issues.  I replaced it but now but I'm still getting the "Check Hybrid System" error message and now the car will not start at all.  

I didn't have time to load balance the cells yet since I don't have the chargers yet.

I have a feeling the safety plug is not engaging properly but I've tried everything to get it to engage that I can think of.  Hopefully someone can help.  Anything else I can try?  Its a PIA pulling this thing out.  

[Britprius]

12 hours ago, hban398 said:

Hi all, been following this thread for a while since I've got a 2007 GS450H with the check hybrid light on.  I'm in the states but this forum has been very helpful.  Recently my car stalled so I knew the hybrid battery needed attention.  So I decided to change out the bad cell.  I found 1 cell at 6.6 so I knew that was the one having issues.  I replaced it but now but I'm still getting the "Check Hybrid System" error message and now the car will not start at all.  

I didn't have time to load balance the cells yet since I don't have the chargers yet.

I have a feeling the safety plug is not engaging properly but I've tried everything to get it to engage that I can think of.  Hopefully someone can help.  Anything else I can try?  Its a PIA pulling this thing out.  

After you close the leaver you must then slide it sideways. This is the step that most people miss.

John.

[hban398]

Thanks for the reply John. I think I did that. I've tried it a few times now and made sure it slide over properly. 

Now im getting a Check VGRS light and the car still won't start. 

[hban398]

Also, is there way to check the hybrid Battery voltage?  Want to make sure I put it back together properly.  I cleaned all the contacts before re-assembling it.  All the cables are properly connected.  Could I have inverted the 2 orange cables?  I didn't label them and can't remember which one was on top and which was on bottom.  At the moment, the one with a red tape is on top and the one with an orange table is on bottom.  Any harm is changing them around?

[hban398]

So another update - I had the 12V Battery recharged since it was a little low.  Was at 11.6V, now its 12.69V. 

Now when I go to start the car I get the "Check Hybrid System" and "Check VSC Check EBC" lights.  Still won't start.  The hybrid Battery pack looks like it has some charge so I think I connected everything correctly.  Otherwise it probably won't show anything.  

I tried really had to slide the orange plug to the left.  It slides over but I feel like it could go 1 more cm.  See pic where I highlighted the section that its not sliding over.  When I take it out I can slide it over all the way.  Just can't do it while its in the hybrid Battery pack.  Trust me I tried really hard to the the point I thought I was going to break it.  It should just slide over easily.  

Not sure what else to try.  

[Andymgl]

Hi, how do u select right Battery cell for your gs450h?

You said it's important to get the right cell.

I have 2006 lexus gs450h. What kind of Battery cell do I need? 

I'm going to replace some of the blocks

Can I use 2nd generation Prius Battery cell? 

[Britprius]

1 hour ago, Andymgl said:

Hi, how do u select right battery cell for your gs450h?

You said it's important to get the right cell.

I have 2006 lexus gs450h. What kind of battery cell do I need? 

I'm going to replace some of the blocks

Can I use 2nd generation Prius battery cell? 

\yes you can use gen2 Prius modules, but gen3 modules are better. The gen3 modules are the same size as gen2, but have two interconnections per cell instead of one. This not only reduces internal resistance, but reduces localized heating in the cells because the current has two paths it can take. One at the top and one near the bottom of each cell. This enables them to carry more current safely. 

John

[SparkyDave]

Thanks for a great illustrated write up, aceswild. Did it need any further attention since you replaced the Battery module?

Also, many thanks to all the other contributors in this thread.

Have any of you based in Ireland used a hybrid Battery repair service that you could recommend? I'm in Dublin but I've only seen one advertised and it's based in Co. Clare, though they do a mobile service.

Dave

 

[hybridbatterysolutions]

On 12/2/2015 at 10:53 PM, aceswild said:

Sounds as if your battery was fine, did you have any fault codes before you started? It could be the converter or the likes, it's quite a complex system. I recommend having a dealer run a diagnostic on it to point you in the right direction.

I’m afraid voltage is not a good indicator of Battery condition what you need to know is capacity which is volts x amps (power) x time - that should point you in the right direction 

Richard

[hybridbatterysolutions]

On 4/5/2018 at 6:48 PM, SparkyDave said:

Thanks for a great illustrated write up, aceswild. Did it need any further attention since you replaced the battery module?

Also, many thanks to all the other contributors in this thread.

Have any of you based in Ireland used a hybrid battery repair service that you could recommend? I'm in Dublin but I've only seen one advertised and it's based in Co. Clare, though they do a mobile service.

Dave

 

I have done 3 from various parts of Ireland- not being funny but I really would not trust “on the quick” repairers - it takes a good 7 to 10 days to do properly anything less will be at best a very temporary repair (obviously I am biased so please ask around for yourself)