total discharge of hybrid battery performed, effects?

Finally seeing dealer tomorrow for an 'interrogation' of mechanic of what was really done or how an aux battery replacement in a Prius is performed in general (I am sure to be told 'cannot remember, too long ago').
I am now very well equipped with 'expertise' thanks to you all!
Actually Prius is due for a car service.
Another thing jumped into my mind trying to find an explanation (Prius is still drinking more fuel than before), if the mechanic maybe used the touch screen to check on the new aux battery and by doing so maybe by accident altered some settings, just clicking around.
I seem to have very high fuel use in the first few meters, sometimes even after minutes and kilometers (30 -99L/100km), even when coming to a full halt, I hear the engine really roaring fully even when being not moving at all. The idling maybe. No idea and no idea what it was like before after a cold start. I will see what will come back on Thursday or Friday. THANKS AGAIN!
Anyway I sure will make clear that such dodgy explanations for high invoice of 'more work, had to discharge battery' to a woman do not satisfy at all and are questioned, not forgotten. ;-)

 

Now, I was told by the service advisor today in a very grumpy call, that The Training Manual states that a Hybrid battery ALWAYS had to be DISCHARGED when a new auxiliary battery was replaced. For safety reasons. So I did hear right back then. Wow ???
And that they then charge the hybrid battery up and afterwards have to always run a full diagnostic check which takes 2 hours, but I was only charged one hour work, so i should not complain about costs.This check should avoid a faulty discharging, a wrong assembly or loss of energy by avoidable drain.
He gave me the number of the Toyota Customer Experience Centre 1800 252 097 to complain there if I thought the manual was wrong.
Now the other interesting part is, that my car all of a sudden uses 5.2l/100km as if the injector nozzle was cleaned out. Maybe this was a timely bad coincidence and had nothing to do with the hybrid battery performance at all and ran in circles for nothing. Hang on, funny still, that they actually fully stand to a discharging procedure of hybrid battery for aux bat replacement.

I will continue to monitor the average fuel use for my unchanged routine drives. The high use in first minutes at the moment seems to be due to cold weather, but that was the case before the aux battery change with the jump in fuel consumption straight afterwards. Now all seems good, BUT I promise you, I will ask why a dealership has to discharge the hybrid battery for an aux battery change according to training manual. I will have to find a copy of it, I will have to find the training place ( said to be in the Docklands of Melbourne) before I can contact Toyota Australia or Japan why on earth they do this to the hybrid battery. I don't like it, they seem to fear idiots handling the car or what. These are professionals. Or maybe the manufacturer plays it safe to be not sued in case someone runs into 110v by touching something he shouldn't anyway.? No idea.
But interesting result and confirmation.

 

Oh, just did below. In short : They DID discharge the hybrid battery and say it HAS to be done according to a manual!

 

" just did ABOVE "

 

hello again,
I need this ominous 'Training Manual' to find out for us. ;-)
(is anyone of you in the forum a mechanic in Australia and has a training manual for Toyota hybrid to prompt the truth?)
....maybe there is an Australian version of the 'Training Manual for Hybrids',
that makes it 'saver than save' assuming the mechanics here might touch the bonnet instead of the boot for an aux battery change? Just, I don't want to pay for unneeded work, even performed.
But Mr.Uart,
I don't know how you can be sure
that they did not discharge the hybrid battery if the service advisor even confirms it on the phone to always do discharge the hybrid battery according to 'the Training Manual' ?

Where is hope still?
Also the dealer, who brought back my Prius in the evening, was grumpy as and said that they have to discharge the hybrid battery (well, he was talking to the same advisor)
I don't like my hybrid battery to be touched, flattened and then charged for no good reason.
The system never allows a total discharge (as you said, it goes down to two bars, but then it does load).
Which miscommunication could be there, when I get told
'yes, we discharged your hybrid battery fully before doing the aux battery replacement as we always do,
the Training Manual says we have to do this for safety reasons, and the hybrid battery get's fully charged afterwards and don't worry, we run a 2 hour display check therefore, which you are only charged an hour work for'. (as if any mechanic would sit there 2 hours and watch the screen.....)
The service/dealer should never charge an hour work for something 20 minutes aux battery replacement. In my opinion:
It is their problem, if they perform for 'safety reason' more than needed.

 

Little note CONCERNING FUEL EFFICIENCY:
I don't think it is the ECU's learning.....because of something, that is not worth upsetting the dealer or discussing while it was for my better:
I smile silently: the fuel economy display of suddenly being much better (5.2L/100km) was based on a -hold on tight- 47km calculation only!
(and stays since I drove my Prius yesterday and today 200km, but still too early to cheer, I know)

Now comes my little smile:
One way from my home to the dealer is already.....ca 45km shortest, directest way.
While I filled the car on Wednesday and handed it over to him with about 30km on the calculation display, it should have returned with about 130km on the calculation average fuel use display, rather more than less (because he drove home with my Prius first).
Instead, my car comes back and he showing me mobile phone pics of the performance while driving of 4.9 and 5.1L / 100km calculations on his drives and says to me 'we don't understand, what fuel economy should have changed'.
I just smiled, because I am happy my Prius is again from one day to the other via dealer back there, no, even better, where it should be.
I am so sure
that they have either charged something at dealership/service, cleaned something or set something, then opened the fuel tank to reset the calculation and voila:
even the dealer can drive my car now fuel efficient AND what is best, I just did some routine drives, my fuel economy seems to be better than before. hehehe. From one day to the other again.
Side effect: For me it proves, that the discharging of hybrid battery did not have an effect on the battery performance itself as so many suggested and guessed it would be the case. Proven.
But I do doubt why they did it at all, which comes with a risk and cost.
It might well be, that the 'new' 12 V drained something and got due to my nagging fixed, but covered up. (who admits a mistake) ;-)
From one day to the other all is good with the fuel economy, it seems.
Changed as quickly as it changed the other way, both times coming back from the dealership.....

 

Thank you so much!!!
I have just downloaded your link, read through and will print/ send it to the service advisor and kindly ask to send me his copy, where it says anything about discharging the hybrid battery for this specific reason.
I found once a webpage (but lost it), where it said 'careful with hybrid cars because of high voltage. Always discharge the hybrid battery IF you touch any orange cable'.
I can only guess, that they might have a similar introduction in their Manual, but forgot to have the 'if' clause sink in.
If I get hold of a copy of manual of this service advisor (which I doubt), I will annoy you all one more time and post it. On the other hand, I might upset the dealer and service department a lot with my questioning their procedure and what if they do change their procedure and one gets electrocuted accidentally unluckily .... would I be to be blamed?

 

Thank you too so much!
1) I have replied before, I have my own little guess concerning fuel economy, that they actually covered something up like your suggestion of a 'bad new 12V'. The fuel economy seems to be good now, but I do not think it is due to my car's learning, because: all too sudden, all too much connected with 'a day at the dealer'. But if it is finally good, I am just all .
2) For their procedure of 'discharge hybrid bat before auxiliary battery replacement' I might ask for a copy of their Manual posting them a print out of Toyota official manual, because I seem blind to see the 'safety' bit and want to know about a 'correct' Manual version. Also such different procedures reflect different costs for me as a client.
There seem to be no certified standard in Australia regarding Hybrid training unfortunately. Still in baby shoes. But dear me, if they skip the hybrid discharging thanks to my interrogation and one 'good' mechanic (you always get the odd ones out, don't you) gets a little 110V shock but unluckily through heart, by doing something not correctly, but blaming and suing the Manual writer (cannot sue me, I am not a professional, am I) that 'it would not have happened if the system was discharged'...... I just can think, that here in Oz they overdo it with safety for 'just in case' cases. ??? But I don't want to pay the cost for it.

 

Thank you all, thank you Mr.Uart!!!
The call to the Customer Experience Center recently was an experience in itself, she (the consultant) did not disclose a full manual or address/contact details of Toyota Prius Training facility for me as well and to follow up of my question about 'discharging hybrid', if this made sense for my aux replacement, she contacted... the dealer and I got told again:
'it could be fatal due to high voltage in Prius if we did not discharge the hybrid battery for replacement of a 12V battery. It has to be done that way. That is according to the manual'.
They really play 'stupid' with a customer, how on earth can a questioned procedure be confirmed as correct, if the person for verification is the person I am questioning and again everything just orally?
I search the internet and there is no 'contact' I find other than the Center I called.
I can 'buy' a full NHW20 manual via 'subscribing' to toyotamanuals.com.au (consultants idea), which is very expensive, too expensive.
Mr.Uart, thanks so much for the excerpt of the manual, your pdf shows the replacement procedure perfectly,
but does not state the 'disconnect' part, the 'preparation' before hanging in the boot to do it and that is the crucial point of the momentary rest of the argument I have with my dealership.
They never must charge me for their 'extra safety' precautions.
I am after a written piece, a manual page, or a page number, that states what you have mentioned above about 'disconnect', which makes so much sense.
I have your comment, but that might not be prove enough for my dealer. I wished you were my service mechanic in Victoria. You seem to know what to do correctly.
Does anyone have the evidence of 'disconnection' being enough for working on the HV part of a Prius please?