HV battery corrosion

Used CocaCola for Army uniform buttons in the '60s but the Australian formula has changed because it won't do it any more.

 

I would go to an electronics store and get a good quality electrical grease over petroleum jelly.

 

The cell terminals are fairly clean. I could probably take vinegar and a paper towel to clean them up or a soft wire brush. The corrosion was mainly limited to the bus bars and nuts.

 

Thanx for the advice. The salvage battery was bought on eBay and came from a 2009 Prius with 33k miles. I drove 7 hrs to Barneveld, NY to pick it up and the seller was kind enough to help me install it as his house.

My mileage has increased from 41 - 43 mpg to 46 -48 mpg so I am happy with the purchase. The salvage battery cost me $625.

On the original battery, I tested the 28 individual packs once the bus bars were removed with a Fluke Meter and all are showing voltages ranging between 8.00 - 8.06. The battery was fully charged prior to removal. Does this seem OK, or is my Fluke Meter messed up? I was expecting to see a max voltage reading of 7.2.

Mylar

 

8+ volts just after charging is normal (your Fluke is fine). They will quickly drop a couple tenths in a day or so and then very slowly discharge from there over a period of months.

Since your battery was in good shape, why did you get a replacement?

JeffD

 

Jeff,

My 2006 Prius has 93K+ miles on it. Since purchasing 1.5 yrs ago I have seen the MPG's dwindle from 47 - 48 down to 41 - 43.

I had been looking at salvage Prius batteries on eBay for some time. I specifically wanted one from a 2009 with low miles.

Recently I discovered a seller out of NY that had such batteries going for $625 so I decided to purchase one.

Even though all my cells in my old pack are good, I was worried that over time they would start to fail.

I guess you can say I was being proactive in purchasing a replacement before mine failed.

I'm not sure what I am going to do with my old pack, but I might try and sell the individual packs on ebay or here. I can then recoup the $$ I spent on the salvage battery.

Mylar

 

I replaced my 2004 battery with a ReInVolt at 195k miles. 27 modules in my old battery were in good shape so I re-balanced all of them (it takes about 30 hours each) and put them up for sale at $30 each (plus shipping). I now have 6 left so it can be done (but you have to be patient).

JeffD

 

I have thought about reconditioning the entire pack using the X4 charger:

http://www.amazon.com/dp/product/B005MW0WZO?tag=priuschatcom-20 trying to sell it on eBay as local pick up for $800. Also thought about throwing in free installation if given the old pack to recondition.

It might be more of a hassle than what it's worth, or it could be a lucrative side biz...

Mylar

 

That's pretty normal without any grease. High quality very pure copper straps on steel/zinc/alum/copper battery studs. Add constant current draw, hostile damp atmosphere & battery fumes & you have perfect electrolysis.

Been using this stuff for a very long time on residential and industrial panel mains and any high power DC connection. It stays put for years.
It works really good and stops further electrolysis or any galvanization:

Ilsco DE-OX-8OZ at ElectricianSupplies!

They used to sell it at Home Depot. Very handy as it truly works.
Be aware by sanding down the straps and exposing virgin copper it will excite corrosion greatly so grease them up real good or it will very quickly oxidize right back up.
Good Luck!

 

Thank you for the recommendation! I will definitely use this electrical compound when rebuilding my HV battery.

Mylar

 

You were correct! My original battery has been removed from my car for 4 days and all voltages range between 7.86 - 7.88.

How exactly will I get them all to read the same voltage after I cycle them 3 times or is a .02 difference between cells acceptable?

Mylar

 

You will need to let them rest until they all get down to just under 8 volts (it doesn't take long). and then slowly discharge the ones that have a higher voltage till they are all equal. Try not to get them all below 7.5 volts.

You can easily use a charger/rebalancer to do the final discharge while monitoring the voltage with your digital volt meter. Note that the battery terminal voltage will rise a bit when you halt the discharge.

I used a SuperMate DC6 charger/rebalancer http://www.xheli.com/dysudc6dcmuf.htmlhttp://www.xheli.com/dysudc6dcmuf.html to do my battery work. It requires a 12v 5amp power supply (use a laptop supply ~ $10).

A 0.02 volt variance is better than acceptable.

JeffD

 

Hi. Anyone know if the gen 3 Prius is affected by the bus-bar corrosion seen in the gen 1 and gen 2 Prius? Thanks.

 

i wouldn't be surprised, now that they are getting some age on them. but i can't point you to any threads.

 

How do you clean corrosion off the busbars?

Posted via the PriusChat mobile app.

 

Can you tell me after the clean busbars what's the good dielectric grease name or brand...thanks

Posted via the PriusChat mobile app.

 

Yes, I've opened up three Prius Gen 3's in Southern California recently, all near 200k mile, and they all showed significant corrosion. The best was as shown in the attached pic.

The electrical contact point is between the pad part of the battery module stud and the back of the bus bar plate. That is not pictured and has generally shown much less corrosion than the nuts and front of the bus bar plates. Still I replaced them all with new plates and nuts and wiped the battery module plates with vinegar, then water to prep them for the new plates. To be clear, I don't think there was even a total 1V drop across the 240V pack because of corrosion before replacing them. Reusing the cleaned plates seemed sketchy because corrosion caused pitting of the surface, lessening the contact even after cleaning. Besides, after all that effort, I like to leave it bright and shiny!

 

You could try:

Brush on:

NOCO NCP2 CB104 4 Oz Oil-Based Brush-On Battery Corrosion Preventative, Corrosion Inhibitor, And Battery Terminal Grease

Caig DeoxIT Battery Cleaner & Protectant with Brush Lid, 118 g (CL-BCP-04)

Aerosol spray:

CRC 3175 Battery Terminal Protector, 220 mL, Aerosol Can, Dark Red

You would brush or spray these products on after you have attached the busbars to the terminals, not before.

You may or may not be able to get these from Amazon, but you should be able to find similar in an auto part or hardware store local to you.

Also, I'm not recommending you use Amazon, it just happens to be a convenient way to showcase these products to you.

I hope that helps.

[Edit] I see I've been sucked into necrotized thread revival vortex but I'm going to leave this post stand as it will serve to inform anyone that comes along later.