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General Category => General Discussions => Topic started by: rasgariwat on March 08, 2011, 05:44:01 PM

Title: which cell type for replacement?
Post by: rasgariwat on March 08, 2011, 05:44:01 PM

hi all,
I have some faulty cells in my 48V 12AH Battery. Replacement by GM is a bit slow for my taste. Can you tell me a good source for the cells that will fit my needs?

As I understand it is 3.8V, 4AH cells that I need.

thanks for helping, and, btw, I am in Switzerland.

regards
andi

Title: Re: which cell type for replacement?
Post by: DirtyGinge on March 08, 2011, 07:26:39 PM

Hi There

i believe these are close, but please double check, there is another li-mn cell on the site

http://www.bmsbattery.com/cells/12-4ah-3c-c-rate-26650-g-limn2o4-cylindrical-battery-cells.html

Regards

Title: Re: which cell type for replacement?
Post by: _GonZo_ on March 08, 2011, 07:55:13 PM

Quote from: rasgariwat on March 08, 2011, 05:44:01 PM

hi all,
I have some faulty cells in my 48V 12AH Battery. Replacement by GM is a bit slow for my taste. Can you tell me a good source for the cells that will fit my needs?

As I understand it is 3.8V, 4AH cells that I need.

thanks for helping, and, btw, I am in Switzerland.

regards
andi

Hi Andi,

If your pack is already used as much that some cells are already died then:
It is not a very good to replace bad or old cells with new ones in a used pack.
And totally bad idea to mix different type/model of cells.

The problem is that the the good cells in your pack are not new now, so when you add new cells to your pack you make a very imbalance pack, and if you do not have a very good BMS the old cells in the pack will die very soon and may be some of the new ones. That will end that you may need to replace again some cells and you will mix again old and new cells...

I strongly recommend you that you get a new full pack.

Title: Re: which cell type for replacement?
Post by: MonkeyMagic on March 09, 2011, 06:57:13 AM

If you charge/balance the cells they will be fine depending how old the original pack is.

Speaking from personal experience, it's alot of trouble. I had to replace 5 cells and any more then it was better to buy a complete new pack. So have a big think if you just want to pull apart the pack and use the old cells for other things. That might be better.

Ginge unfortunately posted the wrong link, please be very wary of inferior batteries - you need the 'orange' color at least, because the blue cased cells are generally always from lower rate batches too
(no offence mate!)

The link you want is this one (http://www.batteryspace.com/limnnirechargeable26650cell37v4000mah10arated148wh.aspx) and make sure if you order them to select 'with battery tab' so you can cut the tab to fit in-line with the GM pack to squeeze it back into the casing

Looking back on it, I would still go with Gonzo's advice.....

;)

Title: Re: which cell type for replacement?
Post by: DirtyGinge on March 09, 2011, 09:54:12 AM

oops.......

i did get that link from another post here, but it was late...ill be a bit more careful in future ;)

regards

Title: Re: which cell type for replacement?
Post by: rasgariwat on March 09, 2011, 01:38:05 PM

thanks gentlemen, appreciate your input a lot.

my pack is about 1 year old. I understand that it is wise to buy new. And in the meanwhile I can get some cells and fiddle with them.

best
a