60v 30ah lithium battery hack

[egoad]

Hi, my first post so thanks in advance to any help...!

I have a 1year old 60v 30ah battery for my 2000w phat tire scooter. the battery stopped working correctly, would only charge to 64volts (instead of 67volts?) and would cut off around 62volts when i run it. It works fine for that small amount of time, but is only about 20% of what it was intended for.

Question, I sent it for repair but they wanted to change all cells at an horrible price. If i peel it open and identify a bad batch of cells, can i disconnect them from the battery pack (perhaps leaving a 60v ~20ah battery) without any risk? I am thinking perhaps only a set of cells is bad. The issue just happened all of a sudden, worked fine prior.

sorry for the long question, any advice?

Cheers! 8) :?

 

[999zip999]

One-year-old so it's out of warranty ? where did you buy it what country do you live in and what country did it come from ?

 

[999zip999]

After answering the first set of questions. You would like to know the state of charge of the battery. I guess it's 16s ? Anyway you need to find out the voltage of each parallel group of cells starting at the neg end as #1. You have to write it down on a piece of paper oh you have to write it down on a piece of paper.

1. 4.10v
2. 3.95v
3. 4.09v



16. Xxx volt
This is State of charge.
Now battery voltage .
And charger voltage
This after you answer first questions.

 

[egoad]

yes unfortunately just out of warranty. bought US (e-drift, now 'fatbear' scooter).. I live in US. I am 'assuming' there may be bad cells as the change in the way it would work happened suddenly.

I also 'assume' that because it only charges to 64v (instead of 67v, which is what i read when on charger) that there is some sort of bad cell combination. Not sure what the BMS has to do, but perhaps only charge to lowest denominator. Perhaps the whole unit is going bad, but hard to see that its only been through 60-70 charge cycles and stored properly..

 

[egoad]

oh, just saw you from dana point..! i was just there at doheny beach campground last week..! i am in carlsbad.

 

[999zip999]

Then you know about the raceway from the end of state beach to North San Clemente ? The k rails to keep out the cars.

 

[999zip999]

Ok what access do you have to the BMS and or battery ? How about a pic ?

 

[egoad]

lets see if these pics work, have not cracked the blue case open but plan to .

 

[egoad]

hmm only lets me upload 1/2 MB...

 

[egoad]

so no did not see or hear about the raceway (perhaps someone mentioned it).. sounds interesting.

in regards to pic, i am limited on this forum, its just a blue wrapped battery from china. power lead and charging lead.

 

[john61ct]

If some are bad, the rest will likely follow.

Order known-good cells yourself

then either DIY or find a known good uilder to assemble for you.

I would not deal any further with those that ripped you off

assuming it did not fail from your mistreatment

 

[egoad]

good point. i found a repair place called 'FTH Power' near LA (city of Industry to be exact). They would not fix bad cells, but offered to rebuild it with new quality/name brand ones. problem is they want $850 for the 60v ~20ah config..

i think the place i got it from will give it to me (after 30% disc) for about 375. My math was if this lasted a year, it would still take 2 years to get to the price of the legit battery. am i missing something?

in 2 years, who knows what kind of battery will be avail. thoughts? and thanks for the replies too...