Traction Battery Preventative Maintenance - Hybrid Automotive Chargers

Hi Chris,

My apologies, I have read some of your other posts where you use the term "the burn", but did not make the connection here, so got the wrong end of the stick.

Whilst that is true, we do have mountains to rival those in Colorado. However, not near where I live so I've not taken my current Prius over them. Having said that I have driven a Gen II Prius in the German mountains which is where I experienced having a fully charged HV battery for the first time. I did not however experience the drained HV battery with accompanying loss of power when making the ascent. Maybe my battery was in good condition not being used in regular mountain driving.

I am 100% certain that the HSD control system has ability to configure itself so that it can burn off excess energy once the battery reaches that nominal full 80% mark. It uses a combination of engine induced drag (to replace regen braking), running one of the MG's against the engine and hydraulic brakes to ensure the HV battery does not exceed 80% and that the car remains under control.

I'm sure that the major reason is that those high milage batteries experienced a much more gentle life and/or climate compared to those that are failing.

 

Jeff, congrats on the new products you've got out now but if you need a beta tester for a Highlander version I would certainly be more than interested in helping you out with that.

 

Thanks for explaining that "engine compression braking" phenomenon--driving down the long gradients on the edge of the Rocky Mountains in US and Canada I have experienced that sudden loud "whooshing" noise along with high engine rom several times after the top bar in the battery indicator was lit for a minute or two on the descent. 'Twas disconcerting, indeed.

 

Ok, well keep me in mind if I can be of any assistance and in the meantime I eagerly await a version for the HiHy as well.

 

glad to hear the 50-60% PWM control on the fan speed. Standard Prius operation also meter the fan speed.

So if the pack is brought up to full - 8 green bars, either by going down hill or by an Enginer type of set up, then use the top off grid charger to fill the remaining 20% SOC, how many hours would you suggest to leave the grid charger on ? 8 hrs ?

thanks

 

I'm sure that the major reason is that those high milage batteries experienced a much more gentle life and/or climate compared to those that are failing.[/QUOTE]

dolj,

No need to apologize for not understanding my reference of "The Burn". Having lived with it for 2 years now and having done some extensive testing and treatment for it I forgot most Prii owners will never experience it. Us high mileage people have all kinds of issues, LOL.

I don't know which thread it was in or when but there has been some in depth discussions on battery life expectancy. The general thought is the two biggest contributors are heat and cycling. Heat is obvious, excessive heat just isn't good for batteries. Cycling is when a battery goes from full charged to fully empty or in Toyota's case the upper and lower software limits. The more cycles you put on a battery the closer it is failing. That is why I have a theory that high mileage Prii that are driven mostly on the highway show fewer HV failures. At highway speeds unless I am climbing a hill or stuck in traffic I rarely full discharge my HV battery. There is always some amount of recharge occurring from coasting, slight downhill or simply not accelerating. That is why Ema can have some many miles but may have actually fewer HV battery "cycles" than someone who only has 100,000 miles but drives mostly in the city at lower speed, sits in traffic or takes a lot of short trips.

Anyway, sorry for the tangent. Thanks for the downhill recharge information again, happy driving.

Chris

 

Jeff,

Looks like a great product and certainly something I would be interested in. I do have a couple of questions.

1. The shop lists two options for your charger, “standard” and “discharge ready”. Although there is an * next to the listing it does not explain the difference. What is the difference?
2. It is hard to tell from the picture and from the instructions, does the control module have to remain in the trunk? My trunk is very full with my toolbox, various meters and other work equipment. It would be better if the control module could be unplugged and the cable covered with a lock type screw cover. It appears to be an amphenol so do you include this cover with it? Or does the control module have to stay plugged in even when not in use?
3. Would a shop that works a lot with Prii be able to install this while Ema was having some other work done if I didn't have the time. I was thinking of a shop like Taylor Automotive in Sanford, NC. I would think this would be a walk in the park for them if they haven't done any already.

I look forward to hearing from you. Please feel free to PM me if you have any questions.

Chris

 

Since I am familiar with the products I'll chime in.

Standard charger can only do charging. Discharge-ready means you can attach a discharger to it as well. Discharger is sold separately. I recommend all my customers get discharge ready and discharger so you can get the full benefits of cycling your pack.

Main control box can be removed an set aside. Only need it in the car when you want to charge.

Any experienced mechanic can install it. In fact a high end car stereo guy might be a good option too since they know about working carefully with powerful electronics.

 

Thanks for the quick response. Is there a cover for the cable included when you remove the main control box? I don't really want dust, dirt or fines getting in there and potentially causing a problem.

If installing the grid charger was all that was going to be done you are probably correct about the car stereo place. Unfortunately I doubt Freeman's would want to install my new catalytic converter, LOL.

Thanks for the info.

Chris

 

I got my 04 Prius on July 27, 14. The battery looked good by the MPG of 50 on the MFD.
I just got my Mini VCI and it showed the battery voltage at 15.3 average, with 3 bars on the MFD.
Then the engine turned on to charge the battery. The charge climbed up to 17.3 V average per bank.
After the engine stopped the voltage slowly dropped to 16.5 V average. I turned off the motor and Mini VCI so I do not know what the final voltage settled to. The A/C was off but the ventilation fan was on. Battery temp was 90 deg F.

14 banks X 15.2 v = 212.80 V
X 16.3 = 228.20 V
X 17.3 = 242.20 V
Since the actual battery max voltage is 28 packs X 7.2 V = 201.60 V
I was wondering what is going on? Why is the battery voltage so high?

I really like the HV charger. Would it be useable in cold weather to keep the battery warm for better fuel mileage? It gets really freakin' cold in Michigan!

 

The nominal voltage of NiMH cells is 1.2v, which is what the 201.6v is (168 cells x 1.2v). NiMH cells can exceed 1.4v when fully charged, which is about right for you max value.
Other battery chemistries are the same way, a 12v lead acid battery is really about 12.6v when fully charged.

 

Thanks, I am glad to see that I have a good battery pack even after 10 years of use. That's amazing!

 

Ran over to Taylor Automotive in Sanford, NC this morning to have them install my grid charger and a new catalytic converter on Ema. They did a good job with the install and its nice not to have to clear the CEL with my scangauge every trip, lol. Ema is in the garage getting charged up as I type. I will post back later how it goes and if I see any improvements in MPG's or have any issues.

I'm a little disappointed in Taylor because I specifically went there to have a different set of eyes on Ema other than mine or my regular Toyota Tech and they have a lot of Prii experience. They didn't really look at anything and I didn't even get the obligatory "change your air filter and cabin filter" spiel. I know for a fact my tires need to be replaced and the front brakes are at 4mm so that should have been noted at a minimum.

Happy driving,
Chris

 

Can't wait to see how it works for you, and if you can tale a difference in battery performance. Is your battery original?
Hoping to buy a grid charger for my beloved 05 with 231,000 miles.

 

Would love to get updates from you since you know Ema so well and give such detailed recountings.

Happy ridin' indeed!

 

I have purchased 4 of these and use them daily. I highly recommend this product and Jeff's support is top notch.

2x get the discharge ready version and discharger.

I am happy to help any one needing installation or advice in the Tampa area.

 

Hi Jeff, this is awesome! I'm looking to purchase the discharge ready version. Got a few questions though...

1. Is this 110v or dual voltage? If 110v only, i assume a step-up transformer is needed and will it be safe to use? (edit: sorry, just saw the specs and it can do 240v AC. awesome!)
2. Can this be used to charge only the traction battery daily without fear of overcharging?
3. Is there an option to choose between "charge only" and "charge n balance" or is it always in the one charge n balance mode? If so, how will i know if it reaches 80% and i need to turn it off? Do i need to do it manually by unplugging and turning ON the car to check the SOC?
4. Does the HV battery fan always come on the moment charging begins, or when it is in balancing mode, or is somehow temp dependent?
5. How much would shipping to Australia be?

That's it for now.. Thanks!