36v 20ah LiMn Battery Update.

[Ypedal]

After a season of gentle use, the Lithium packs are due for a health-check !

So.. we strip the Chaos down !

Again.

 

[Ypedal]

I can't beleive i'm actually doing this....

 

[Ypedal]

So far so good.. after aprox 60 cyles of 50 % DOD, roughly 30 to 40 km per cycle = 1800 to 2400 kms ( I know it's a rough estimate, but the numbers are impossible to calculate exactly )

 

[Ypedal]

There it is !

Looks good, this is how a pack should be, .. checking voltage of cells now..

 

[Ypedal]

Cells:

1- 4.14v
2- 4.13v
3- 4.14v
4- 4.13v
5- 4.14v
6- 4.13v
7- 4.13v
8- 4.14v
9- 4.12v
10- 4.13v

8)

 

[Ypedal]

And pack 2 :

 

[ott]

Wow those numbers are great! (you sure your meter is working ?)

 

[Ypedal]

Notice the white crease on the end .. when i received the packs, this one had one cell pushed up higher than the rest ..

 

[Ypedal]

Pack 2

1- 4.08v
2- 4.06v
3- 4.07v
4- 4.13v
5- 4.09v
6- 4.14v
7- 4.07v
8- 4.11v
9- 4.08v
10- 4.07v

 

[Ypedal]

Bottom of the pushed up cell, this does not seem to have caused any problem yet, i pointed this out when i received it but was told to try it and see how it goes :?


Pack 2 is in need of manual ballancing, i hope the cells perk up and keep up to pack 1, will report back once i finish bench testing them.

 

[recumbent]

Good to see the cells holding thier own and well ballanced after a season.

I have the same chemistry but never checked the cells yet, guess i should do it this winter.

Thanks for keeping us informed.

 

[fechter]

Did the blue ones turn yellow?
LiMn?

Where do you get those?

Do I dare ask: how much $?

 

[Ypedal]

I purchased these from FalconEV. - ( Need to check.. but i beleive it was 1200 $ )

The packs came from :
http://www.gbp-battery.com/

When i contacted FalconEV i was very specific that these packs would be used at 72v with a 20 amp controller, and these were recomended. ( Paid for both these and my LiFe packs at the same time )

Now, logic says that 2 packs used together should come from the same production run or have the same age etc..

However, as you can clearly see.. one pack Green and one pack Blue ( only found this out yesterday !! i was not aware of the blue and green underwear :x )

The green pack shows it's age, not yet sure if it's a ballancing issue or simply age yet.. will ballance and test shortly. ( Need to find a single cell Lithium Manganese charger )

What i suspect happened here is that the green pack was aquired and used/abuse?/tested.. and i was sold a 2nd pack to match it.

To further prove this was the case, i received 2 different chargers.. one 2 amp and one 4 amp ... not great on a 72v bike.

 

[Ypedal]

Another detail i need info about..

I have noticed this since day 1... but the battery packs have a strong solvent smell, hard to describe but very noticable, is this normal ? anyone know ?

 

[TylerDurden]

Another detail i need info about..

I have noticed this since day 1... but the battery packs have a strong solvent smell, hard to describe but very noticable, is this normal ? anyone know ?

Where's the Scratch & Sniff Internet when ya need it???!!!



Smells like...


Petrol?

Ammonia?

Vinegar?

Alcohol?

Laquer?

 

[Ypedal]

ISO alcohol.. ie: Rubbing alcohol .. would be my closest comparison.. :?

 

[oatnet]

Another detail i need info about..

I have noticed this since day 1... but the battery packs have a strong solvent smell, hard to describe but very noticable, is this normal ? anyone know ?

When I got LiMn packs, one of them had a strong, almost ozoney smell. When I realized it was just one and not both of the packs, I opened it up. It turned out the BMS had been damaged in shipping and had melted down, but current was still trickling through it. It didn't smell like fried electronics, just a really strong odor.

It seems like you have a good view of the BMS's, and I'm not sure if this is actually at all similar to what you are smelling, but I figure I'd throw it out there.

Could it be glue they used on the packs, or that clear sealant on the BMS?

-JD

 

[Ypedal]

I made a small ballancing LBD unit, opened up my 3 x D cell Mag-Light and soldered 2 wires with aligator clips to equalize the cells and re-charge the pack to full capacity, then a DOD test to see how much they deliver ( something i have not yet done, only used max of 17ah once)

The smell seems to come from the heat shrink, not sure what toxic brand they used or if it's just that they burned it on a flame instead of using a heat-gun, but after airing the packs out for a few days the smell has disipated.

 

[Deepkimchi]

Ypedal - didn't want to sound like a kook but that's what my LiFePo4s from FalconEv smelled like, strong odor of rubbing alcohol.

Also funny - they have the same terminals as your LiMn packs.

BJ

 

[Ypedal]

Yeah, it took me a long time to figure it out but i'm almost positive it's the shrink wrap, they must have used open flame and it's a burnt rubber smell that never goes away !

These cells are not LiFe for sure tho, 4.2v per cell confirms that.. no way to tell if it's actually LiMn cells vs LiCo tho.

 

[xyster]

Rubbing alcohol is used to wash electronics after assembly, correct? Perhaps there were airtight pockets of isopropanol left over...