Battery Conditioning as Preventive Maint

I don't know enough to technically analyse this. Curious as to what they charge for this.

 

"Testing" or "Conditioning" the battery will shorten its life a bit. I have a battery cycler/tester for handheld radio batteries. I only use it when the battery begins to exhibit a problem because of this extra wear and tear. The minimum "cycles" these devices must put the battery through is two. That's two less for the batteries life. I doubt very much this service would result in increased battery life. Just based on who offers it I wouldn't go near it.

 

Sounds like snake oil to me.

 

Using their numbers (save over 70% compared to a $4 to $4.5K hybrid battery replacement job), the supplied details sounds like this is a "service" - requiring multiple visits (roughly akin to regularly scheduled chiropractic adjustments) - that stretches the customer's overall outlay to well north of $1000.

Since you don't know what you don't know, fear is the motivator here. Their business model appears to be somewhat similar to that of Terminix...

 

I trust the Prius to know how to condition it's own battery, thank you very much...

 

If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.

 

It is possible to extend the life of the battery.

The normal failure mode of the battery is that over time one or more of the 168 cells become out of balance with the rest "not reaching the same charge level".

This can lead to a situation where at heavy load or discharge of the pack to near it's 40% level completely discharging the low charged cell then reverse charging it. At this point the complete module that the cell is part of is scrap.

Now the very reason we balance the cells when rebuilding a battery is to bring all the cells in each module up to full charge "balanced". If we balance all the cells before problems arise this reverse charging could be avoided could be avoided. The modules can be returned from a 3 AH level to 6.5 AH level.


If you read the posts on plug in conversions one of the things that is carried out is balancing of the cells at every charge.

It is possible to check paired modules with Techstream, and if it can be seen that a pair of modules are starting to diverge from the rest there is no reason why the whole battery cannot be treated in the same way as we already treat individual modules when balancing them.

In short it is possible to charge and discharge to balance the cells the whole battery as one unit or 168 cells in one go instead of 6 cells x 28. The process is exactly the same, but obviously the charging voltage is much higher.

John (Britprius)

 

I tend to believe in the idea of the possibility of replacing individual battery cells as they fail, and the reality that this could be a cheaper than a full battery replacement, and extend the life of a battery pack.

I tend to really question the wisdom in pulling a battery pack to do what is essentially just testing of each cells and some type of somewhat dubious battery refreshing.

My understanding of The Prius battery and the software handling it, is that what we see on our MID displays is actually somewhat disingenuous. That is that the whole system is designed so that the battery even when the display shows it low....down to two bars or less, isn't really that low or totally discharged...and conversely when it shows full or near full it is not really totally full. It's designed to operate as much as possible in the middle. Never fully discharging, never really fully charged.

I may be missing something, maybe even something quite severe, but it was always presented that this way of operation was Toyota's way of conditioning the battery for the longest possible life.

I'd need some convincing that san's individual cell replacement and balancing, that there is any value in pulling a entire battery pack and suddenly discharging and charging individual cells to supposedly restore balance.

This whole operation sounds more like a operation that would probably lead to individual cell replacement, being masqueraded as a test to improve battery function and life.

 

You cannot replace individual cells only a block of six. In that block it is likely that only one cell failed and that cell probably failed because it was reverse charged.

You do not need to "pull" the battery for no reason in can be tested in place.

When you have a string of 168 cells in series it is asking to much to expect them all to stay perfectly balanced without any balancing mechanism. Again the reason those doing plug in conversion go to great lengths to address this issue.

If you read my post carefully and the information give by "The Hybrid Shop" the important information is in the detail. Checking the modules for any divergence in performance. Again what we try to do when rebuilding a battery.

This rebalancing of a working battery was something I posted about some while back. The idea that fully cycling a battery 3 times will shorten it's life is strictly true but not by any measurable amount, and having one out of balance cell could kill it prematurely.

Typical cylindrical NiMh batteries have a life expectancy of 1000 cycles. The Prius battery I suspect is much better than this.It is never fully cycled in fact it is only used to 40% of it's capacity giving it a cycle life in the tens of thousands and most end there life with one cell being reverse charged, because it got to far out of balance over heating and damaging modules close to it as well as the module it is part of.

If we can catch this out of balance before it does damage the overall life of the battery must be improved.

Toyota have just announced an extended guarantee for hybrid batteries where you take your car to the dealers checks are done on the battery and if it passes they give 1 year 15,000 miles extension to the guarantee. This may be done year on year. So they must be able to detect a possible fault before any symptoms show. This could well be low capacity cells that if treated could improve the life of the battery, and if left destroy it. We already know Toyota only fit complete new batteries and will not service an old one.

I have no affiliation with any company in this field I am just a retired EE.

John (Britprius)

 

The display accurately shows you the true operating range as you would expect from an operational display. If you want to know the technical details of the SOC you need a ODB-II reader.

 

Well perhaps I'm mistakenly calling a "cell" that block of six. I know I've read posts where people have stated they have replaced "cells"...but whether they meant "block of 6" or a REAL individual cell? I concede my ignorance.

And that is kind of my point. As the hybrid shop describes their "Battery Conditioning" one of the first thing they say they do is pull the battery from the vehicle.

That's why I say it sounds to me more like an operation of testing for cell failure (block or individual) more than it actually sounds like a action of "preventive maintenance".

I mean, I think most casual owners aren't going to go for "Battery Conditioning" as long as they feel their battery is operating correctly. You are not going to have owners looking at this operation unless they perceive a problem or a drop off in performance.

What are the real chances then that the battery is pulled, put through this operation and no module is identified as failing?

"If the Conditioning process identifies battery modules that need to be replaced, the process would move into the realm of battery pack rebuilding."-The Hybrid Store

That's why I say, this sounds like testing for hybrid battery failure masquerading as a process to extend battery life. Even if it can be argued that testing for hybrid battery failure and catching it early does leave one with options that will conceivably extend battery life.

For me? As long as my battery is under warranty by Toyota, and IS working up to standards, I wouldn't let an outside or independent shop do anything to it...even if it is helpful.

It's somewhat draconian in nature. But as long as my battery is under warranty? Which for me is 10 years or 150,000 miles? Then I'm letting Toyota handle any issues that might arise.

If Toyota starts offering a testing and warranty extension program...then I'll be in.

 

Yeah...but when the little cartoon graph shows fully charged...my understanding is it's NOT really fully charged.
And conversely, when it shows it is low or down to 1 or 2 bars...there is more charge left than it is showing.

My understanding is the system is designed to operate the battery charge and discharge in the middle. As you say, The displays we are shown are just simplified "operating range" displays.

 

Yes I quite agree with not touching the battery while it is under guarantee, but because of your location you are in a better position than most.

My own situation is that my car is 5 years old at 92,000 miles. My guarantee expires at 100,000 miles. Now 100,000 miles seems to me to be a suitable mileage to check my battery "because I have the equipment". If I find a possible problem should I ignore it or do something about it? I think the answer is obvious.

Trouble shooting in industry is about diagnosing problems before they bring things to a standstill or become larger problems. A bearing getting warm may only require lubrication.

This also means you can sort the problem in a time of your choosing.

John (Britprius)

 

Yes, those are all operating gauges not diagnostic gauges. Sort of like the gas gauge, when you have used 3/4 gallon of gas it still shows full and 1/2 full is somewhere more than 0.5 full.

 

The -problem- with all this is often the "out of balance" cell has actually dropped in capacity for one reason or another. You CAN NOT correct this! So you are spinning your wheels if all you are going to do is connect to the "battery" and charge/discharge in some manner. Which is what is being sold. You need to replace a six cell module to actually "fix" the situation.
So it's still smoke and mirrors.

Those who actually take the battery apart and check each module are different that what we are discussing here. They -may- actually be able to "fix" a battery or extend its life.

 

In the Torque App, there are PIDS for specific block monitoring of the battery! You can read the block voltage differences as the car is under load! That would be the way to figure which block is really bad. A good look at the terminals and tightening the terminal bolts and looking for any signs of corrosion is worth mentioning if you are actually going to tear into the back!

 

Sounds like snake oil.

Then again, hybrid cars are basically snake oil on their own based on initial cost of purchase as well as the fact that producing batteries of this size is extremely detrimental to the environment and typically involves strip-mining of mountain rages in order to acquire the nickel or lithium necessary to build a hybrid battery pack.

 

Ah, a repeater of myths!

First, a properly designed hybrid car -CAN- save a lot of money if used in the right way. Driving 20 km per day is NOT the "right way". You need to put at least 20,000 km on it per year, and it works best if each or most drives are at least 20km long.

Second, production of nickle is NOT done in strip mines! Have a look at the Sudbury area of Ontario Canada. It's a deep mine of the traditional tunnel variety, I think still the largest nickle mine in the world. That mine DID indeed cause big problems in the area (a large area), but that was the smelter and was due to sulfur compound emissions causing acid rain. That mine/smelter is now one of the cleanest in the world! But the damage was done in the past. BTW, the nickle produced at that time was NOT for "those terrible hybrid car batteries", but rather for things like military hardware, auto trim, kitchen sinks, etc etc (stainless steel, "chrome" trim and such). Your attempt to blame Toyota or Prius is just silly and uninformed!

Are you receiving a stipend from some oil company? I ask because they have actually admitted spreading these kinds of myths and if you are not being paid you are being used!

 

I'm afraid all the manufactures disagree with you on your first statement. It is almost impossible in high volume production to produce cells with identical characteristics and over time one or more cells in a battery of any size will become out of balance. I suggest you read the item below.

http://WWW.MPOERUK.COM/NIMH.HTM

John (Britprius)