New Prius Owner 2002, battery issues (shocking!)

after you replace the cell, you would do well to balance the pack.

 

All of the Toyota manuals refer to mixing up a boric acid solution. If it's too hard to find boric acid, another acid like vinegar would also do the trick of neutralizing the battery electrolyte, which is strongly basic. Mixing in something already basic like baking soda surely looks impressive, but only defeats the purpose.

The Gen 2 modules (each module is six NiMH cells) can be made to fit in the Gen 1 case with a bit of effort, but the dimensions are different, so one doesn't commonly hear of mixing both types in one battery. It would be hard to attach the bus bars between modules of the two styles.

-Chap

 

Hi Vanionbb, I had good luck cleaning the modules in my gen1 last month with acetone. The advantage over water- based cleaners is it dries off immediately and you can switch off between cleaning and checking for voltage leakage with a multimeter without the conductivity of traces of water to interfere. In the pic below, you will see I used clipped an alligator lead on one module terminal and am reading over 2 volts on the case near the other terminal. This was leaking voltage module-to-module.. You really have to wipe the lead all over the whole unit casing, then swap terminals and leads and do it again...you can probably do the whole bank in a couple hours.
I was lucky and didn't need to replace any modules, I had voltage leaks between modules and broken sensing connectors.
Bought my car dead and down last month like you did, now happily pulse and gliding. I found good advice here on Priuschat.
I charted voltage leakage between adjacent modules and module to battery rack before taking it apart and used that chart during reassembly, module by module, to ensure that I got it the first time and I did have to reclean 2 or 3, but avoided complete re-teardown.
I used and liked the Halogen headlamp trick to check modules for voltage drop under load. The no-load voltage means little. You can find it in postings here. I charted voltage befor load, during, and recovery after one minute.
Some other members here look at internal resistance, I hope to learn that trick some day.
If your terminal sealant is gooped onto the bus bars, acetone and vinegar will clean them with minimal labor.
If you find broken sensor wire connectors, no need for a $100. harness, fixed mine for $2.94
I have a spare cell I got off Ebay last month, voltage is good I have not tested resistance, you can have it for what I paid plus shipping of your choice for speed. Robert

 

There are a number of things that will clean the copper buss bars. If you want a really cheap/effortless cleansing, mix 4 packets of Kool Aid (lemonade flavor) into one quart of water and let it sit for 8-12 hours, wire brush any stubborn stains/deposits and let it sit for another 8 hours. I cleaned tons of salt water corroded brass and copper this way while serving in the Navy. I works awesome and its cheap.

There is a guy on here named ericbecky, he likely has a Gen 1 module and if he doesn't, ask Bob Wilson or scotman27.

 

Chief, your kool-aid brings back Coast Guard memories of Everclear.........thanks for the ping!

 

Not hard to find boric acid at all;

BORACARE, BORA-CARE - Free Shipping

Amazon.com: boracare

You're just looking at the wrong place. Most hardware stores carry it for a safe pest control item.

 

Don't drink the Kool Aid!

I'd be leery of using it as a cleaner as well because of the sugar content. Straight lemons in water with no sugar, sure, but pass on the added sugar.

SCH-I535

 

Who said anything about adding sugar? Do not add sugar, just kool aid lemon flavor works the best. And..., trust me it works and works well. I've used it numerous times.
I just don't understand why it is that when I give advice here, there's always someone that "knows better" and discounts it. I find it odd that those same people offer no solution. How frustrating.

 

Kool-aid has sugar in it, a lot of it. I didn't advocate adding any.

SCH-I535

 

Someone needs to go to the grocery store and look at Kool Aid packet ingredients


Kool-Aid Unsweetened Lemonade Soft Drink Mix (0.23 oz) :: Foodfacts.com :: Find out what's REALLY in your food. ::
Kool-Aid Unsweetened Lemonade Soft Drink Mix (0.23 oz)
ingredients (11)Citric Acid, Calcium Phosphate, Salt, Maltodextrin, Flavors Natural, Lemons Juice Solids, Ascorbic Acid, Colors Artificial, Yellow 5 Lake, Yellow 5, BHA

 

you must be drinking the kool aid. sorry, somebody had to say it.

 

Hi Kentucky, so your lowest voltage module also had the highest internal resistance. I'm trying to apply the resistance formula to the tables of my voltages, but it looks like I am off by a factor of 100...can you please coach me on the calculation.......the term resting voltage-is this the voltage before load is applied........the asterisk in the formula, does this mean multiply...and load do I enter watts or amps? I think I can interchange them using W=VA. My halogen headlamp, high and low jumpered, draws 100 watts or

Bravo! Photo please!

 

vanion, glad you got the modules in time for the weekend and that they look like they will play nice with your existing ones.
Keep me in the loop should you need anything else in the future.

 

Good job to all. Thank you Eric for being a great resource for us here. I hope I don't need anything from you in the future but, if I do, I know who to call.