Prius with a few codes: need advice

very nice eric. i feel at 167k this car has alot of life left. No scrap yard. your wasting money doing that.

 

unless this car has been beaten, rusted out, leaking fluid all over. and interior falling apart. then maybe so. but if its solid and has been taken care of and not busted up maybe just needs a detail. why not fix it. cheaper to fix it than spend 5 yrs paying off 20k + at possibly 3 t0 400 a month payments. thats 2 hybrid batteries a year. or one transmission a year. so before signing that paper for a wopping 300 to 400 bucks scrap. think of it that way.

 

damn..not in your area.. but i am having a similar problem... im definately interested

 

very good, its worth fixing, plus cheaper and more convenient than car payments.

thank you, thats what we are here for. you came to the right place WELCOME ABOARD

 

I think you'll enjoy fixing it up a little and learning about it. I bought an NHW11 in December, having always toyed with the idea of converting a rav4 or cr-v to semi-hybrid, CR-X to electric, or even buying a new Prius. None of those ideas seemed to make enough economic sense, or practical enough, to get me going. Then I stumbled on this dead Prius (mine was $1200, sounds about like yours condition-wise but body not perfect... overall pretty decent. I'm very happy to have it). The car now has around 2k miles since I bought it or 120k total miles. The idea of changing a couple of cells makes perfect sense, it's a bit of a PIA to get the thing out of the car, but with basic electrical/ electronic skills it's not hard technically, and pretty easy after you get it out of the car. I had planned the same repair, but all my handful of tested cells weren't holding any useful charge, so I gambled (having never driven the car) on the new dealer pack. They retail for 2299 I think, being a retired car guy I of course worked a little break there, the dealers are notoriously stingy with their breaks though. I love the little Prius now, driving it more than my 'reliable' 2009 car...and it's given up many of it's secrets to me already, who had never even driven a Prius before. Just now got it reassembled again after a couple weeks strewn around the garage. It got the Toyota navi install finalized, a small amp/DSP with ipod plug, new CFP (lol), and I just added some wires for 'free' cruise control... looks like it's going to need a brake light switch to implement that upgrade, along with the handful of resistors and couple of switches I had imagined). I will post a thread on this if it works out ok, in case others are interested. I wish you the best of luck, there are a lot of helpful people here, and tons of good info. -Rick

 

For all who may be reading this, just remember, there is more to it than just replacing dead battery modules. I don't say that to stop anyone from DIYing but to stop someone from having unrealistic expectations b4 going into it.

Some things to remember are;
1) Modules must be kept under compression when charging
2) module pairs must be matched with capacity and voltage to ensure a lasting repair
3) all modules should be balanced

There are numerous ways of accomplishing these so I won't tell you how (just that you must). Read up on all the examples on here. jdenenberg is your friend.

 

I'm still getting used to the 43 mpg and half price fuel bills, compared to my 20.5 mpg Chevy v8 , and it's so quiet...

 

PriusWI,
I'm back in town and in the shop tomorrow.
Want to give me a call and we can talk?
608-729-4082

Are send me a Private message with a number and a time to call you.

 

I've known Eric for many years and always found him to be a good resource and well worth a call. Eric and his family are the ones who make Hybridfest, now Green Drive Expo, work.

Bob Wilson

 

PriusWI, Yep, Sorry about that. I'll fix the other post.

 

FUD! (Fear, Uncertainty, Doubt) . This thread is full of it. I have repaired five Gen 1 batteries by just replacing one or sometimes two bad modules. The first was in September of 2011. The repair has lasted 17 months and 17,000 miles. The other four cars are still doing fine also. Someday another module will go bad and I will have to put another $6 module and four hours of work into this money pit. Might as well junk it! The voltage on every bad module I have replaced reads 1.2 to 1.3 volts lower than the rest of the pack. That is the result of one cell of the six in a module shorting out. In PriusWI car it will be the 23rd or 24th cell counted from the drivers side of the car. A volt meter is all that is needed to tell the bad from the good. For the PO420 code I would replace the upstream O2 sensor.

1) If you are going to fully charge a module then compression is a good idea. I have charge may cells with out compression.

2) The cars simply do not care if the module pairs have perfectly matched capacity and voltage. There is a threshold of difference allowed. Every car I have repaired had modules 1.2 to 1.3 volts low. .03 or even .3 volts difference will not cause codes. One module in a pair has no effect on its neighbor. Voltage is measured and compared across every 12 cells. That is good enough to detect problems.

3) On one repair I took the time to balance all modules within .01 volts. This was done by leaving them paralleled overnight. Immediately on starting the car the module voltage diverged by .1 to .2 volts. You will clam that this is caused by modules of mismatched capacity and that is probably correct. The point is it does not matter to the car. Now to balance charge a replacement module I use my 12 volt charger set at a 2 amp trickle rate. The actual charge rate is 30 amps. Short bursts of ten to twenty seconds will get it close enough.


The Prius high voltage battery is capable of killing you! Read everything you can before opening one up. I consider the most dangerous part is removing the plastic covers over the buss bars. Even with the safety plug removed there is still 150 volts between the middle and ends of the pack. Wear gloves and work one handed while removing and reinstalling the plastic covers. Once the buss bars are removed from all of one side there is no more than 16 volts to deal with.

Brad Lindberg

 

Personal experience and those of "Prius Technical Stuff" agree with this good advice:

Modules must be kept under compression when charging

The reason modules must be kept under compression is the sides are thin plastic and normal charging generates gas and heat. For example, in this setup, I used a layers of plastic wrap between the plastic plate and back plate to make a capacitance string gauge:

So when I was doing my early tests, I used the MRC930 which has a temperature probe and the VOM with a capacitance measurement:

It turns out that charging the module is exothermic, it gets warmer, and generates a small amount of gas, that bows out the sides. The capacitance increased as expected.

Later in my module rehydration experiments, a failed seal 'bubbled' from the generated gas:

Sorry for the grainy photo but the bubbles are reflecting the light just to the right of the red jumper.

The sides of the modules are thin, flexible plastic as this decapitated module shows:



In one case of an unattended charge from a solar array, damage resulted:

The overcharge broke the compression struts.

But we can see the temperature climb which also causes the modules to expand in this forced-charge event:


module pairs must be matched with capacity and voltage to ensure a lasting repair

What happens is batteries have a charge-discharge curve and they have different capacities. So during my module, rehydration experiments, I was able to return older, marginal modules to like new capacity:

The charge and discharge current is common to all modules. So what happens is a weak module gets overcharged while the stronger ones get undercharged. The overcharged modules generate gas and heat, the enemy of the adjacent modules. But we can see this in the field data:


all modules should be balanced

There is only one current flow and it is common through all modules. The weak modules will get over heated and generate gas to fail sooner. Meanwhile, the strong modules never get a full charge. There will be variability but we don't have to finish a rebuild with weak modules being over-stressed:

These are module capacities that came out of one of my spare traction batteries. The "F" group were the ones that would lead to an early traction battery failure and there were only three of them.

So I fully support your recommendations as I have hands-on experience that shows these are good guidelines.

Thanks,
Bob Wilson

ps. Uh Brad:

Starting out with a criticism of others tends diminishes everything that follows to insignificance. It is a self-inflicted wound that makes subsequent discussions all but impossible. A better approach is to provide engineering and technical data supporting your point of view and leave out the rest. You had a couple of good points but the introduction makes it nearly impossible to discuss because it implies agreement with your "FUD" introduction.

 

It sounds like one of the sense wire in the orange harness might have broken. The KOH electrolyte 'eats' copper and the sense lines can become thin and fragile.

With a Prius aware scanner, read out the voltages of the 19 module pairs to test. If one (or more) measure 0 V, find the break(s) and repair the broken wire.

Bob Wilson

 

Hi PriusWI,

The wires may look OK but you should use a multimeter to test for open/short. Be sure to check the connectors too, I had a P3030 code before and it was the connectors that were corroded.

BTW, the battery block 1 is nearest to the Service Plug and you can also see the numbering 1,5,10,...,35 on the base plate. You should also follow the spec. to tighten the nuts:

Torque:
5.4 N·m (55 kgf·cm, 48 in·lbf)

Over tightening may damage the terminals and cause electrolyte leakage in future.

Vincent