Traction Battery Preventative Maintenance - Hybrid Automotive Chargers

John, "my brother from another mother"

JeffD

 

You may confuse people with statements like that (bitprius confirms in post following your blurp that he is in agreement with you - means you are together in the dark
Facts:
1) SOC as displayed by Toyota system is indicative of the total voltage level of the WHOLE pack. And that is where your confusion comes from. SOC by the way is neither representing battery capacity nor indicating individual module "weakness". The main purpose of SOC metric is to keep battery operating in the "plato" area. Total voltage being enumerated in SOC reading serves the purpose.
2) Weaker cell (increased resistanse and hence higher voltage on weak module during charge) will in fact display the total pack SOC higher than if there were no weak cell. Of course you have no tools to see that, can't blame you.

"Uart" is by the way absolutely right in his way of logical thinking - I have documented evidence and valid tests about that...

How about showing you SOC = 70% or 100% of the pack where the total battery capacity is around 2.7AH and it has 2 dead and 2 ugly cells in there?

 

You are absolutely right and this shows your logical thinking
I have documented evidence and valid tests around that... probably need to post on my site to educate people...

Here is the way you may look at it in a simple terms

Just SOaCk this:

SOC (state of charge) is representing the combined voltage of all modules and assists the vehicle's hybrid system to operate in a " plato" or "Shallow" area of discharge curve. Imbalance at the bottom (picked and displayed all way trough by delta V) is kept out from the operational "shallow" range as long as the capacity of the weak modules/pairs disallow to get imbalanced area closer to the operational range. Capacity degrades with time and imbalance at the lower end meets and cross the operational range. That is where they say: "Huston, we have a problem "

That means that efforts to "improve battery performance via whatever charging maintenance" by using "black magic" "grid/greed" charger attempts are complete waste of time. Car will charge the pack in a nick of a minute with 50A charge and bring all modules quickly to the upper level. Do not be naive in assuming low current charger or slow charge/discharge routine can do any good for you...

You find lot of folks here are dreamers. "talks about SOCs" give them something to chat about ...
Similar like people from Wall street love "talks about StOCks"
And grandmas who spend their golden years knitting love "talks about SOCks"

Sorry to being so SOCcastic

 

I think the problem here is that in your quote they are talking about actual SOC and you are only talking about the displayed SOC.

SOC is just State Of Charge. So if some module has higher internal resistance and because of that it’s going to have higher voltage during charge doesn’t mean it (or the battery) has higher actual SOC.

 

You are one funny guy bisco.

 

sometimes, a picture is all that needs to be said.

 

Hello All,

I am a newbie to these forums, but I am attempting to repair my Gen II (and eventually my Gen I) Prius battery with a P0a80 code. I have started a thread for it here:

Tips or Tricks? Attempting a Gen II Battery Repair for the First Time | PriusChat

Based on S Keith's advice, I am looking at possibly purchasing an HA grid charger to streamline the cell rebalancing after I replace any bad cells. However, I am running up against a slight problem. Part of my reason for attempting this repair was to be able to service both my Gen I and Gen II Priuses, but also to be available in case my family's Gen III or Prius C's go bad, or any of the other 4 Priuses owned by my friends go bad. I convinced most of them to buy Prii and would like to have the skills to help them if their battery packs go out.

Do you offer a grid charger that works with all generations of Priuses? Steve recommended I check with you to see if we could work something out (see last post in linked thread).

Thanks much!

SeaFoam

 

Hi Jeff,

Is the wire harness for the Gen1 charger compatible with later generations? Would I need to change any settings to optimize the charger between generations? You mention that the current would oscillate between 200-300mA, is this opposed to staying steady at 350mA? What would be the effect of the lower current?

Sorry for the question spree, just very curious.

 

Jeff,

He was also concerned about the Prius C with it's 144V pack. Can a Gen 1 charger accommodate that lower voltage reliably?

Steve

 

I am NOT suggesting to buy any chargers. As you DO NOT need the charger in principle. Do not waste your money.
Use of external chargers in Toyota hybrids is not required.
The only situation when you need charger for Prius is when the battery needs to be load tested (e.g. on High Voltage Battery Analyser) and then charged for storage or when battery has self-discharged because of the long time in storage (Toyota Operating Procedure).

I know what I am talking about. My High Voltage Battery Chargers have no fluctuations of current. My chargers for Prius C can outputs 1A, 1.5A or 2A Constant Current with no fluctuations. My Chargers are Isolated Type High Frequency Chargers incorporating genuine power supplies designed by reputable manufacturers and made in New Zealand with main critical components made in Japan / S.Korea and Germany and they form part of the High Voltage Battery Testing Complex. Details are here: Testing Complex - HYBRIDS

I have not updated photos of the latest chargers on my site - e.g. there are no photos of those 4 new models I've designed and built over Chrismas period with digital meters and of those in a small form factor boxes. Those were made to accompany my Analysers and are not for sale separately . I also have Chargers for Lexus (genuine Toyota chargers for 288v Battery packs - 40 x7.2V modules).
I have also built and tested negative pulse or so-called "burp" chargers to test somebody's [unsupported] claims about miracles they can do. And proved that they can't..

FYI: any type of so called "rebalancing" or "reconditioning" with the use of any type of chargers as promoted by some incompetent ppl here and there is complete nonsense. FYI: The use of chargers in Hondas has been an attempt to compensate for the mistakes in Honda's BMS and not relevant to Toyota. Building chargers from LED drivers was Honda enthusiast Mike's DIY project in the absence of access to proper components and tools (now Jeff's charger) - is not IMHO the way the proper charger should be built. That is why their chargers are cheap and can't deliver high currents by the way.

I am not offering you to buy my chargers or any other HV chargers if you have no tools to test the whole pack at once on the individual module level.
Just buy yourself RC charger for $25 on eBay and be happy DIY-er...

 

"Entending the LIfe of the Hybrid" by the use of the so-called Grid Charger offered by Jeff is fraud in my educated opinion as an Electronic Engineer. Hybrid Automotive have never proved their claims. Except from bla-bla-bla...

 

You are selling individual modules on eBay, am I right? That is another fraud to lure unsuspected people into beleif that change of individual modules is the right thing to do... No surpise that my honest opinion is attacked..as I am putting into the spot light the dodgy dealings of so many fraudsters who jumped on the opportunity to make money out of people's ignorance and offering them things they do not need or things which will not work" like grid chargers or individual unspecified modules on eBay.

Again, you have produced no hard evidence. I've looked up your graphs after you charged batteries with the LED charger (perhaps that is the most sophisticated equipment an aviation engineer (you said you the one, right?) can make . Those are by any standard not an evidence of any improvements. Many people are doing tests straight away after charging batteries and are observing a bit of increased capacity. That is common. There are standards of testing NiMH which you are probably anaware or never heard of (as they are not available in your language). Do proper testing following at least one reputable standard (say Department of Transport US use) and document results in a manageable form - then we could be discussing or arguing Grid Charge Improvement. And that is my point addressed to any claim made by anyone. FYI: the offensive abusive manner you choose in your posts - mind you - I am New Zealander - so, please, mate - make like a ship and flock off...

 

I suggest that if you ever do that or anyone else does - stick to discharge current close to 6.5A - that is workable amperage from many points of view and close to 1C so also can be compared to the results Department Of Transport US is publishing regularly.

 

Here's a word of advice for S Keith and Jeff,
Don't even acknowledge kiwi the loser.

 

+1

John

 

Before you take the peck from someone else's eye - please take a log out of yours. You are promoting pirated Techstream / VCI which you are using in your tests and encouraging others to use it by soliciting CSV files. That is illegal criminal behaviour. You may not consider yourself a criminal... The Copyright holder for Techstream may have different opinion on that....

As for different numbers measured at different currents - that is normal behaviour of the battery.

Capacity of any rechargable battery could be nominated at 1C unless specifically outlined in the datasheet by the manufacturer.
Department Of Energy (link to their site and summary of some test results are on my site) use 1C or 1/2C as a reference, hence I suggest that for comparison.
Live tests of course can be conducted on the car where, during the start, current could be about 90A.

Load test at 6.5 Amps would show different results vs load test @1 A load (higher capacity) or @20 or 90 A load (lower capacity). My Avatar is a screenshot from the LIve test capturing the moment of the 28.8 Amps load. I have tests conducted on the new fresh battery with my High Voltage Battery Analyser @ peak 90 Amps.

This forum as many other technical forums have their "regulars". I remember asking one very specific question on the elctronic engineering forum years ago at the beginning of designing the HV Charger. They provided no help, no direct answer and I've been attacked by "regulars" who were like you and very few others mocking around. The end result from that experience was invention and engineering all by myself of 2A High Voltage Constunt Current Chargers. None of those "regulars" self-proclaimed gurus were able to advise and I had to do all hard work on my own, building multiple prototypes, experencing two moderate electric shocks (thanks God I am still here).

Some perhaps are having fun observing picking with Jeff and yourself. I am not. My point is: if you make a claim as Jeff does on many occasions and in many places on the Net - present your findings in a manageable format, comparable and verifiable.

What publically known facts are (correct me here):

• Chargers are just charges to charge the battery. They are not designed to improve the battery. Do not mistake them with desulfating (for Lead Acid) or Crystal removing (for NiMH) machines. Jeff's charger is just a charger which is capable of charging the battery at a very low current.
  
• Batteries degrade with the number of cycles of charge-discharge - i.e. the more cycles - the more they are degraded regardless of you using low current grid charger from Jeff of High Current from Amrel (The Hybrid Shop) of a Burp Charger or any other charger.
• Batteries in any battery pack (Li / NiMh) could, for the number of reasons become out of balance (different Level of charge not to be mistaken with the different individual Full Charge Capacity (FCC) of the module).
  
• Nobody had demonstated on Priuschat that "being out of balance" has been observed in the pack where batteries have the same remaining capacity. Topics start only after the pack had experienced failure when few modules degraded.
  
• If there are few modules in the pack which are degraded vs the rest - that pack will have reduced Usable Remaining Capacity and after certain threshold being set up in the system - you'll see the error code.
  
• Prius BMS does not have balancing mechanism like Li Packs have (e.g. Nissan Leaf) or Laptop Batteries have.
  
• Being out of balance reduces the Usable Remaining Capacity (my terminology) in Prius. But not nessesarily reduces Prius performance if URC it is still high enough (e.g. 5AH vs 6.5AH). That is why people do not notice reduction in MPG in years although the URC is lower than in the brand new car.
  
• Refilling the evaporated electrolyte with original can increase battery module capacity (patent from the manufacturer) - none of Priuschat members is capable of doing that.
• Removing or Reducing Crystals in the degraded NiMH Prius modules is an unverified claim rather than documented laboratory proven fact (The Hybrid Shop has not demonstrated that crystals were actually reduced in size). Unless I am missing the screenshot from the scientific microscope somewhere.....

What I was pointing to ppl defending the use of the Grid Chargers is: try to demonstrate using comparable test result how the prolonged use of the grid charger improves battery performance and not dergaded the pack quicker by applying more charge cycles to it.

Charger can't rejuvenate individual degraded battery module. But it degrades good pack....
It is like eating in McDonalds - it gives you some junk fuel to carry you along but eventually we all going to die..
Hopefully not from the electricity, may the Lord be with us all...