Engine overworking with little Turtle Sign on the left

Your model sounds like an NHW10, the one that predated the NHW11 that we've seen in North America. There were substantial changes so it isn't clear which scanners will handle the codes from that model.

You might also visit the Yahoo Group,"Mk1_Prius" which has a number of English-speaking, NHW10 owners. I know New Zealand has a lot of experience with this model. Also, some Australians.

I remember seeing some postings about replacing and/or repairing the battery strings in that model in that forum. It also has a number of photos.

Bob Wilson

 

speaking of bob, there he is. a good man

 

thanks a bunch, hopefully we can get your problem identified and fixed, one thing is you dont want to keep driving the car, the more you heat that battery, the worse its going to get. i was lucky enough that i didnt destroy the other cells next to the bad one because that battery was hot. like hot enough that your hand couldnt stay on it for more than 10 seconds.

 

It has been a while since I last visited the Yahoo Group Mk_1 but I remember the "D" strings have a special stripe along side. It has a function but no one had given a credible description of what it does.

What little I know about the NHW10 comes from a Toyota paper, SAE 2000-01-C042, "Development of the Hybrid Vehicle and its Future Expectation" by Shinichi Abe. But this is more of a compare and contrast paper. The technical details of the NHW10 are only referenced.

Bob Wilson

 

wait, is hannahs battery different than ours?

 

Just to keep everything interesting, because you're driving an NHW10, your battery won't look anything like what's in all the cool vids and pics of NHW11 battery repairs. Our batteries are made of 38 rectangular modules containing 6 NiMH cells each ... yours is a pile of individual D-sized NiMH cells (arranged in sticks, I guess, though I've never had a chance to look at one).

All the basic ideas and safety precautions should apply, but the details will be different. There seems to be an Auckland business that knows a thing or two about NHW10 batteries (though I'm not sure yet what their "Power Jockey" is, or what I should think of it). It also seems that Toyota still has new NHW10 batteries available for sale.

-Chap

 

hannah, then that video link i sent you is useless for your car. thats for our version of the 1st gen prius. thers gotta be a write up somewhere for yours

 

Yep, all of the Americans replying here probably have never worked on a NHW10 because the NHW10 was never sold outside Japan. It was JDM only. Yep, on the D-cells on the NHW10 and the change to the rectangular format starting w/NHW11.

 

It has been years since I was a member: Yahoo! Groups

The number of posts change over time but:

27 - May
129 - Jun
62 - Jul
16 - Aug

Here is a site claiming to sell these battery strings: 7.2v 6.5ah Toyota Prius Mk1 Nhw10 Replacement Battery - Buy Prius Mk1 Nhw10 Battery,Prius Nhw10 Battery,Prius Mk1 Battery Product on Alibaba.com



Prius Battery, Prius Battery Products, Prius Battery Suppliers and Manufacturers at Alibaba.com

As I read the ads it looks like the minimum order is 20 strings at $50/string . . . $1,000. So before considering this, it makes sense to contact other NHW10 owners and see if there is any other interest in getting some of these strings.

I can't help on how to take the strings out of the NHW10. But I would first suggest trying to survey all of the strings.

Please do not consider buying a bunch of "D" cells with solder tabs and trying to make your own. Heat is the enemy and the right approach is welded tabs. These cells pass serious current so do the job right.

Bob Wilson

 

If you are in NZ i suggest a quick look on "trademe".
There is a trader called Mirek who sells individual banks of cells tested? and will even fit them i believe if in Auckland.
Also Toyota NZ will sell you a new battery for $3500NZ in response to a "Fair Go " TV program concerning controversy over a repairer called "The Battery Clinic"marketing a "power jockey "booster that masks a bad battery with poor capacity.They also appear to run under the name "Green Cars"
I would stay well away from this unit as it appears to be in essence a cheap grid tie inverter,running off the 12v battery.
Should you or anybody at a later stage buy any newer model prius (gen 2,3 or Estmima hybrid)i have used "Ecomotive" in Glenfield Auckland .They do all warranty repairs for "The Clean Green Car Company".
I do not know if they touch the older model at all,but you could ask.
They have been exceptionally helpful to me including selling me individual NEW CELLS for my HV battery.
It is cheaper for them to buy New and then break down a Prius battery for the Hybrid Estimas than to buy a new one for them.

If you are electronically minded,it may be worth considering placing a diode across the radiator Temp inputs on the motor controller.The orientation does not matter,nor will it stop motor over temp alarms.In many priuses that don't get much low speed or long runs it is not unusual for the battery to obtain a memory effect due to the initial charge on start-up and lose battery capacity.This diode fools the motor into considering it is hot and stops the motor kicking in on initial start-up,until battery voltage drops.This forces the battery to be used.
My prius NW11 has 285K on it with this configuration and runs fine,with only one cell having died at around 250k after car left sitting for 6 weeks.I changed it out as a pair.I still get 20-22k/ltr (around 60MPG imperial not US)
I did this for my wifes ex husband's 1998 Prius and that allowed the battery to regain enough capacity by being forced to run on it without the motor running on gas by deliberately crawling on battery power until the motor kicked in and then foot off the accelerator until motor stops charging battery and accelerate until the motor kicks in. Accelerate gently-then foot off over and over again
That got rid of the turtle and returned a rather dead battery to a usable condition over a year ago after doing this for around half an hour,each time the motor starting to charge the battery closer to the turtle coming up,until it bet it.It is still running quite happily without seeing a turtle since.

You may however have a dead cell rather than a capacity restricted battery pack.

The pin outs are exactly the same on the NW10 as the NW11

CLIPS on RIGHT OF ECU UNIT CLIPS ON LEFT OF ECU UNIT
S See the clip and groove instead of pin NOTE the groove on the otherside
On the clipside of the plug in picture. Of the plug in picture

SOME ECU’s HAVE BEEN INSTALLED UPSIDE DOWN that is why you have an inverted diagram as well​

USE PLIERS TO PUSH PINS IN BACK OF THE PLUG BY EACH WIRE​

PUSH HARD UNTIL THE UNITS PINS PUSH IN ONE AT A TIME.​

Pins 14 & 22​

As shown and reinstall the plug​

NW10/11ECU Pictured LEFT-HAND DRIVE(America) BEHIND GLOVE BOX. you only have to release two plastic securing pegs on the left and right to allow removal for easy access. RIGHT HAND DRIVE –remove two Philip screws at bottom of dash ankle height, one on each side under the steering wheel, then pull plastic dash towards you-it is clipped in. ECU is in the same physical spot in both cars as below
.

​

ECU CAN BE PUT IN UPSIDE DOWN as in this picture
WHAT CAN AND WILL HAPPEN-Please read so you don’t panic.
ENGINE ALARM LIGHT COMES ON-it should not –check you’ve got the right pins
YOU GET OTHER ALARM LIGHTS UP OR BRAKE ALARM LIGHT STAYS ON-FIX by removing and refitting unit pins in the right place-you’ve got it in at least one wrong pin position.The alarm should disappear immediately it is corrected.
IT DOESN’T WORK FIRST TIME-you see no change in your car. it is easy to push a unit pin into the plastic by the plug pin and miss making an electrical connection with one of the pins. Try again, push in close to the pin wire when redoing.
YOU WILL EXPERIENCE periods initially at either fully charged or discharged where the motor will continually charge for a period, maybe over a quarter of a tank of gas. There is nothing wrong with your battery cells-This is normal as the battery control balances your battery bank at each end of its range, after each session you will notice longer battery only runs (more capacity able to being used) During this period my fuel economy dropped back some, after which I noticed even better economy.


Best of luck

 

hope these pics fill the holes in above-not so computer savvy as to get it all up at once.
Graham