cell identification help

simonastro

simonastro

10 µW
Joined
Jul 15, 2014
Messages
5
hi there

i'm a novice trying to repair the battery pack from an E2GO scooter (UK 2010). the battery pack is the removable li-ion only type. on inspection it contains 4 groups of 8 pouch cells of which 4 have decayed and expanded. the remaining 4 of that group measures <6v but the other 3 groups are holding at 6.6v.
individual pouches I assume are around 1.5v and I'm wondering if I can replace them.
I don't know the Ah rating but E2GO literature claims either 20, 26 or 40Ah. the charger delivers 4 x 15v @ 10A.
I've trawled li-ion battery lists but have found none at these dimensions - 116mm x 97mm x 11mm approx.
there is no branding on the foil but there is this code

-ALP11100120
+HY922110110

I wonder if anyone would have advice on how to proceed or information about the provenance of the cells?

many thanks

simon
 
A lithium ion cell should have a voltage of between 2.5 to 4.2 volts.
If your cells are outside that range, they are either trashed or some other chemistry (unlikely)
The charger voltages don't seem to relate to a 4P, 8S lithium pack...
..can you confirm the motor system voltage.?
 
yep, i cannot follow what you have. it is easiest to just take picture of your equipment showing the battery packs and how it is wired up so we have some idea of what you are talking.

download the picture to your disc and then use <upload attachment> down at the bottom below the text box. find the picture and open it and then 'add file'.
 
we call that 16S2P and if you have 6.6V on each of those sections with 4 pouches then each cell has 3.3V on it. the ones with puffing are the ones below 6V? when you say decayed, that means the voltage is very low, lower than the <6V of the others that puffed also?

the puffing and low voltage go together. it looks like the battery is made up of pouches with the tabs clamped between metal pieces to connect them in parallel (2P). in that case you could remove the 8 sets/16 pouches that are puffed up and swap out one of each of the remaining 8 sets of 2P pouches and use them to make a new pack that would be 16S1P, and then buy 16 more pouches of the same dimension and put the new ones in parallel with the older pouch on each channel.

so now the problem would be how to find lithium ion pouches of that size, which is what you asked.

knowing the width, length, and thickness you could troll through alibaba and see if there are identical lithium ion pouches that you could use but then the tab location/spacing and length would be critical too since the tabs of the new pouches would have to exactly match the original so it could be clamped together with the original pouch in parallel.

these pouches might be lifepo4 too so that would be the first thing to verify. there may be labels somewhere.
 
thanks - I understand now the configuration.
I shall continue the alibaba quest.
i've lost four cells =0v. the next four are (in pairs) 3.01v and 2.88v
do you think these could be revived individually on a 3.7v supply?
if I do source them do you recommend pairing each new pouch with an older one?
would be easier to fit the new 4 (or 8 if the others don't revive) as a group.

cheers
 
firs thing is determine cell chemistry. rule out the lifepo4 and then the Ah will fall out from the size and weight when you search since pouch cells of same capacity have same weight and dimensions (volume).

if the pouch is not puffed you can charge it up. if you charge up through a wattmeter so you can measure the current then you can watch the charging profile and if the voltage shoots up vertically as the charging current drops off to nothing at 3.65V then it is lifepo4. otherwise it will be the lithium ion.
 
that is excellent advice thank you
I shall purchase a watt meter asap.
many thanks
 
you should see if there are clues about what kinda battery chemistry if it is not printed on the case. does the charger have a label that tells what the voltage output is?

it is unusual for a lithium ion pack to be 16S but that is normal for a 48V lifepo4 pack.

a lithium ion 48V pack is usually only 13S or 14S which it appears your pack is not.

so if we know what the charger voltage is then that will be the best clue.
 
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