2007 GS450h Hybrid Battery Compatability

[jl5]

Hey guys.

So I just purchased an 07' Lexus GSh for $5k CAD knowing that it will need the hybrid Battery rebuilt. It was imported from California with 83k miles or about 134k kilometers.

I've already pulled everything out, tested voltages, load tested, and am currently cycling the modules right now.

My question is, which hybrid batteries (Toyota/Lexus) are compatible with an 07' Lexus GS450h?

I'm getting a lot of mixed feedback researching online. Some people are saying if switching to gen 3 packs that it is best to switch all the modules together, while a Toyota tech says that Gen2/Gen3 batteries are interchangeable. There are also differences in the batteries between 05-07 and 08-11 GS450? 

I'm a little lost here and don't want to be buying batteries I don't need, so is there anyone here who knows which Toyota/Lexus hybrid batteries are compatible with my car?

Thanks in advance for any help!

[Steven Lockey]

Its not quite that simple. 

A Battery is build from cells. So long as the capabilities of the Battery in total are sufficient then they will be compatible.
I'm assuming you have a hybrid Battery in the car currently. 

So, you basically have 3 options:
1> Get the Battery reconditioned - this will likely involve replacing some dead cells. The replacement cells will want to be of the same
type as otherwise it can create an imbalance in the Battery. All the cells in the Battery should have the same spec. This is more than
just discharging/recharging them I believe it needs a specialised unit to do.

2> Replace the cells - You can have all the cells replaced, in which case any set of cells which meet the requirements of the car will
do, just all cells need to be of the same type

3> Replace the entire Battery - Basically the same as #2 but replaces bit surrounding the cells as well. Overkill IMHO.

There's no reason you can't use different spec cells in a Battery, but its not ideal as the differing internal resistances of the batteries,
how quickly they might lose power e.t.c. will all vary, from what I understand is makes the cells more likely to burn out faster
in the future when an imbalance occurs.

Personally I'd advise giving  www.hybridbatterysolutions.co.uk a email. I had the cells replaced for the hybatt ones he does
and they have been perfect so far. Still got the box of old cells sitting next to me waiting for the lockdown to end so I can sell
em! 🙂 Cost 2.2k for a completely new Battery with 3 year warranty all included. While been in CA he probably can't help you
directly, hes a nice guy and can give really good advice. I've seen a few US companies offering a similiar service.

Honest truth is, messing around the hybrid batteries is dangerous, I used to work as an electronic engineer and I still backed off
at it, so if you aren't 100% sure you know what you are doing, I'd strong advise getting an expert to look at it for you. High voltage
DC is dangerous and unlike AC, if it shocks you, you tend to clamp down on it instead of been thrown away, meaning its far
more likely to kill you. Saving a bit of cash isn't worth risking your life over.

[jl5]

1 hour ago, Steven Lockey said:

Its not quite that simple. 

A battery is build from cells. So long as the capabilities of the battery in total are sufficient then they will be compatible.
I'm assuming you have a hybrid battery in the car currently. 

So, you basically have 3 options:
1> Get the battery reconditioned - this will likely involve replacing some dead cells. The replacement cells will want to be of the same
type as otherwise it can create an imbalance in the battery. All the cells in the battery should have the same spec. This is more than
just discharging/recharging them I believe it needs a specialised unit to do.

2> Replace the cells - You can have all the cells replaced, in which case any set of cells which meet the requirements of the car will
do, just all cells need to be of the same type

3> Replace the entire battery - Basically the same as #2 but replaces bit surrounding the cells as well. Overkill IMHO.

There's no reason you can't use different spec cells in a battery, but its not ideal as the differing internal resistances of the batteries,
how quickly they might lose power e.t.c. will all vary, from what I understand is makes the cells more likely to burn out faster
in the future when an imbalance occurs.

Personally I'd advise giving  www.hybridbatterysolutions.co.uk a email. I had the cells replaced for the hybatt ones he does
and they have been perfect so far. Still got the box of old cells sitting next to me waiting for the lockdown to end so I can sell
em! 🙂 Cost 2.2k for a completely new battery with 3 year warranty all included. While been in CA he probably can't help you
directly, hes a nice guy and can give really good advice. I've seen a few US companies offering a similiar service.

Honest truth is, messing around the hybrid batteries is dangerous, I used to work as an electronic engineer and I still backed off
at it, so if you aren't 100% sure you know what you are doing, I'd strong advise getting an expert to look at it for you. High voltage
DC is dangerous and unlike AC, if it shocks you, you tend to clamp down on it instead of been thrown away, meaning its far
more likely to kill you. Saving a bit of cash isn't worth risking your life over.

Thanks for your reply Steven! 

I figured that I'd take a shot at replacing the bad modules and see if I can do the repair myself, learn some new skills, and save a few bucks before ordering a new or reconditioned Battery.

So far, after pulling the Battery out. I've tested the voltages and found at least one bad cell. All the voltages were around 8.1 - 8.06 volts except for one obvious module which clocked at 6.78v. I'm assuming this module is the one that set off the CEL (Check VSC, Check EBC, Check Hybrid System) and threw the following codes when voltage difference threshold is exceeded:

P0A80

P3017

P0A7F

Afterwards I load tested each module with a headlight bulb drawing 4.3 Amps and measured the voltage drop after 10 minutes and found another cell that had a relatively significant voltage drop compared to the other modules (-14.5% drop, compared to an average of around 8-10% of all the others). It also had a lower starting voltage of 7.69 as opposed to other modules which held between 7.79-7.83 volts (Battery sat for about a week at this point).

Right now I'm in the process of cycling deep discharge/charging, re-peaking, and then fully discharging again to chart out the capacities of all the batteries and again seeing if there are further bad modules and restoring capacity to whichever ones I can.

Afterwards I'm planning to balance the Battery by matching the similar strength batteries with one another and then replacing them in the car. I'm trying to do it properly the first time and if I'm successful then I would like to share what I've done to help out fellow GSh owners.

My problem right now is figuring out which batteries to order, and which Toyota/Lexus models are compatible with my GS450h. So far it seems like all gen 2 batteries are compatible which I will have to order at least two of. I just wanted to make sure and see if anyone had any knowledge on which models specifically are for sure compatible so I can place the order with peace of mind and not have to worry about waiting 2 weeks for an incompatible module.

Of course I don't recommend it as a DIY to those who aren't at least a little mechanically inclined, but the entire process so far has not been too difficult.

I'll be sure to follow up with updates on how it goes!

Thanks again for your advice, much appreciated!

[Steven Lockey]

Sounds like you've got an idea of what you need to do. 

Only thing I'd say is if you aren't doing a full re-condition and testing the batteries at max draw, you'll probably find you are in the same
situation in a few months and have to do it all over again. Its unfortunately nearly impossible to tell if a cell is about to go like this as
they often only show any sort of performance drop right before they are about to start having issues.

Its just if you have two cells failing, there are likely a couple more just waiting to go. A full recondition helps to prevent this. It uses several
techniques to try to remove the crystal layer that forms on the anode of batteries 

To be honest, as you've done most of the work already, I'd be tempted to see if there are any hybrid shops near you that have a reconditioning
machine and see if they will run your cells through it cheap since the disassembly and reassembly is a good chunk of the work. 

And I agree, its not to difficult, the only issue is that literally one mistake and you are dead when dealing with high voltage dc, so please
be very careful when you are linking the cells back together.

[Mihanicos]

Hi,

Your car should have a NiMHi Battery of 40 cells connected in series and its capacity should be 6.5 Ampere hours. There are some differences between the various GS models destined for various countries but all manufacturers try to use the same parts as far as they can to minimise their costs. As far as I know your car should have the same modules as the Prius, for the same type of Battery. For some of the latest models, they are using Li modules.

As long as the modules you get come from the same capacity Battery, and they are of the same size, they should be ok to use. As another member pointed out, the internal resistances will vary and a good diagnostic tool will read them. Try to match the internal resistance of replacement modules to them.

Because the Battery is made from 40 cells connected in series with copper " busbars " it is of paramount importance to make sure they are clean and corrosion free.

Any contact resistance through each of these busbars will be added to the total circuit resistance of the Battery and this will reduce the charging current and the current delivered by them. There have been cases that a bad connection caused codes to be generated relating to the hybrid system.

If you decide to repair it, it is a good practise to put the 10 modules from each side in the middle and the 20 from the middle to put them 10 on either side.

 

Chris.

 

 

I

[steve2006]

I have also read what Chris refers to regarding the copper contacts and washers causing a high resistance.

Could I please suggest you invest in your safety, buy a pair of these gloves and wear them at all times when working on the hybrid Battery pack. They may save your life!!!!!

I have to wear them my self for my job and admittedly they are not easy to work in but provide protection against electric shock.

Class O electricians gloves rated up to 1000V.

[Lwerewolf]

Just about every NiMH module that's not from an RX or an LS should fit - best practice is to use same generation modules due to potential differences in chemistries, but people have mixed modules with success. RX models use  9-cell modules, LS models use 12-cell modules. Don't know of any others that don't use 6-cell modules - assuming that it's not a Li-Ion model, of course.

Since you mentioned cycling, load testing and etc - I guess you've read up on the subject. Put the highest capacity modules in the center - should ensure uniform degradation, as much as possible.

If you want to get adventurous - people have rehydrated modules successfully, search priuschat.

Good luck 🙂