Replacing the NiMH soon...which bus bars ?
 

Hello all,

Looks like a new battery is likely to be needed.
I am getting new NiMH modules, Gen 4, manufactured in January of 2019 and new bus bars to do the swap - 40 old modules out, 40 new ones go in..
I have a choice between OEM copper bus bars and Nickel plated copper bus bars.
Which one to get ? Copper or plated copper ?

Thanks

Re: Replacing the NiMH soon...which bus bars ?
 

Doesn't really matter. The only advantage to the nickel is they won't corrode, but that rarely matters unless you live on the coast or in a very humid area. If they're going to cost you < $2 each, it's probably worth it.

Before installation, confirm the tops of the modules are smooth UNlike your old ones, and the first four digits of all serial numbers of each module are XX1U.

Re: Replacing the NiMH soon...which bus bars ?
 

This is what I am getting - 40 modules

https://cimg3.ibsrv.net/gimg/www.gre...bd46ffe793.jpg

Re: Replacing the NiMH soon...which bus bars ?
 

Those are indeed the Gen4 tops. Unfortunately, the individual telling you they were made in January 2019 doesn't know what they're talking about DDMY, 12-4-19 - April 12, 2019.

Is this Hometown?

Re: Replacing the NiMH soon...which bus bars ?
 

So...all this is good, right ?.....I should have a new battery once I put 40 of these in with Nickel plated bus bars....can't wait to see the difference.
I will do the test/recording of data tomorrow and post it. Really would like to see how bad it is and then repeat the test with the new set of modules is installed.
The date on the modules is indeed April 12, 2019. Thank you Keith.

https://cimg7.ibsrv.net/gimg/www.gre...20d6a1f88b.png

Re: Replacing the NiMH soon...which bus bars ?
 

Good thing you went with the nickle you live in a area with 70%+ humidity .. year around Be sure to tell us how it drives with the new modules :)

Re: Replacing the NiMH soon...which bus bars ?
 

Is this Hometown?

If this is all legit, then you should have a "like new" battery.

Before and after recording would be great. The one caveat is that the rate at which the block data is collected is slow enough to create skew in the data. It's best to do a recording during a near constant current discharge.

Re: Replacing the NiMH soon...which bus bars ?
 

Don't know what "Hometown" is...sorry...

Re: Replacing the NiMH soon...which bus bars ?
 

Hi all, I was wondering if there is a video tutorial floating somewhere that has good instructions on how to take the GM Hybrid pack apart to change the modules...
I have seen most of what is posted on Youtube on Prius packs but have not found a comprehensive one for the GM pack....Would like to know for example which end do you take off so you can slide the modules out ? The fan side or opposite ? How do these come apart ? There always is an easy and proper way to do things and then sometime you have to re-invent the wheel....So....tech advice and how to info is needed...Thanks.

I will have the new modules by the weekend. Ordered 1000V protection gloves, 1/4" Torque wrench to have the 48 in.Lbs in the range, Will have new nickel plated bus bars and nuts for re-assembly.

Any suggestions ? Advice ?

I would take it to a hybrid battery shop to do the swap but the closest that even exists and would do it is 180 miles away and the other 220....so, I think I can handle it. I m an engineer, Material Science not Electrical but if a tech was trained to do it, if I can find the info I will train myself....besides...it is intriguing to the see guts inside it, take it apart and rebuild it better....that is what engineers do anyway.

Re: Replacing the NiMH soon...which bus bars ?
 

I'm not aware of a tutorial, but here are some guidelines:

The "sliding modules in" techniques on Youtube are pretty much garbage. it is MUCH easier to completely remove the clamped assembly, stand it on end and remove all 40 modules, replace with 40 "new" modules and then re-clamp and re-install.

TAKE PICTURES. There will be routing and temp sensor placement that will be very hard to reproduce without pictures.

Priority 1 - immediately remove all the bus bar straps from one side of the pack - typically the side the safety plug is on. This "disarms" the battery to a collection of 20 14.4V batteries.

Completely remove the bus bar strap from the other side - typically the one with all the sensing wires.

In almost every case where it appears to be necessary to remove something in the process, it is easier to remove it vs. trying to work around it.

Each module is attached to the bottom of the case with a small 5mm thd machine screw, 8mm hex + Phillips head. These must be removed before the clamp can come out. When you go to replace them, START them all first and then just get them SNUG with a screwdriver. Do not over tighten them.

I don't remember if the main leads are plugs or 6mm nuts/bolts. If 6mm nuts or bolts, 70 in-lb. If they happen to be the same 5mm nuts as the terminal nuts, 48 in-lb.

It's very straight forward. Allow 4 hours from start to finish. Get help removing, installing as well as manipulating the pack on the bench unless you are strong enough to easily lift and manipulate about 130-140# of nickel and steel in a bulky format.

The 1000V gloves are very unnecessary. I've done hundreds and don't own a pair. They are very bulky and pretty useless for detail work. If you practice even basic electrical safety (avoid touching anything high voltage and/or wear 9 mil nitrile gloves), your biggest risks are back injury from lifting and sheet metal cuts.