help fixing segway x2 i2 battery pack

TahoeJoe

New member
Joined
Oct 4, 2019
Messages
9
Hello All,

New kid on the block here..I recently purchased 2 - x2 segway's, both with dead batteries, both red lights. I was able to use the float charge method I read about atsegwaychat .org
I actually got 3 out of 4 ofthem charged and working again :D

There's not much more info onsegwaychat.org about repairing or rebuilding packs, but it looks like this group I where I need to be right now. Im so happy to have found you all.

Ive never built a pack , or played around with a 10 yr old battery before,so to get even one working again is a huge win for me, as these packs are $900/ea new. I know I certainly wont see a whole lotmoretime out of them, but they do work for now, and Im grateful for that.

I do have the one that still goes to red and just wont turn green. It is accepting a float charge and measures 62V prior to reinstalling and charging on the segway, just like the other 3 did. But, this one wont turn green after trying the same methods used on the others. I tried several times. You would think if the other one from this same set worked, why wouldn't this one too?

I opened the battery case up (which was not fun), and tested each cell and noted the voltage on top of each group. All cells within the group tested the same voltage noted on the pics. In other words, I was looking for dead cells, but there were no individual cells that appeared or measured 0v, nor were any cellsa different number from any of the others in the same group. ( Im feeling this means something, but dont know what?! )

Like, perhaps the wire that goes to that specific group of cells is bad? Ive never done this before, so just talking out loud. I would really like to at least try anylower cost options before just quitting.Re-solder any bad looking connections? Replace the 12 low voltage cells? Forget it, you're gonna kill yourself?


Photo's below


There's two groups that are only testing .02v and .25v, those are the two groups I would think should be replaced.
Please be kind and clear, im new to all of this.[size=small]Thanks so much for any input. [/size]

[size=small]Joe[/size]

[size=small] image_rqijqp.jpg

image_sfoiwi.jpg

image_edrjig.jpg

image_jijxrw.jpg

image_oslyts.jpg
[/size]
 
try to charge the .xx Volt "pack" alone with a lifepo4 charger.

if they hold charge they are good. if self discharge, 1 cells is draining all the P to death.

usually i swap dead ones with new or recovered cells.

i dont own electronics, only battery pack
 
I dont have a lifepo4 charger, but I do have a 0-60V 0-5A Switching DC Power Supply

image_xhghnx.jpg


Do you mean I should try to charge a smallgroup of 4 or 6 cells, that has a low voltage value of 0.25? or .02? like this:


image_ygwkok.jpg
 
Yes if you set the Powersupply to the highest one of your measured voltages and then set the current about 100mA(per cell so a group of 3 would be 300mA). Connect it to the Lowest cells first.

This will trickle charge the low packs. Once a pack gets up to 1.8V then you can crank up the current and let it charge up the rest of the way.

Setting it to the highest pack will force balance the entire pack.


Once the pack is balanced then let it sit for a week or so and then test the voltages to see if there is any significant voltage drop of those low cells. that may indicate problem cells
 
jdeadman said:
Yes if you set the Powersupply to the highest one of your measured voltages and then set the current about 100mA(per cell so a group of 3 would be 300mA). Connect it to the Lowest cells first.


Thanks man! OK, i'll try this.
Is it ok to leave the cells as they are in the pack and just connect the + and - of myPower supply to that one group of 4 cells? I'll try the lowest group first that measures only .02v

So am i understanding this right, im trying to find the one (or more) cells thats ruining it for the whole pack?
One other thing I noticed.. of the 3 other batteries I fixed, this one is the only one that made a slight spark when connecting it to thePower supply. the 3 others didn't do that. Could that mean thispack has a short in there--somewhere?
 
Yes as they are all in parallel which you can think of and 1 cell
 
TahoeJoe said:
jdeadman said:
Yes if you set the Powersupply to the highest one of your measured voltages and then set the current about 100mA(per cell so a group of 3 would be 300mA). Connect it to the Lowest cells first.


Thanks man! OK, i'll try this.
Is it ok to leave the cells as they are in the pack and just connect the + and - of myPower supply to that one group of 4 cells? I'll try the lowest group first that measures only .02v

So am i understanding this right, im trying to find the one (or more) cells thats ruining it for the whole pack?
One other thing I noticed.. of the 3 other batteries I fixed, this one is the only one that made a slight spark when connecting it to thePower supply. the 3 others didn't do that. Could that mean thispack has a short in there--somewhere?


i push every cells our of the pack

https://secondlifestorage.com/showthread.php?tid=7073

those 0.02V should be dead or very low capacity (they starve under 2.5v and kill chemistry)

but sometimes they are still good
 
jdeadman said:
Yes if you set the Powersupply to the highest one of your measured voltages and then set the current about 100mA(per cell so a group of 3 would be 300mA). Connect it to the Lowest cells first.

This will trickle charge the low packs. Once a pack gets up to 1.8V then you can crank up the current and let it charge up the rest of the way.

Setting it to the highest pack will force balance the entire pack.


Once the pack is balanced then let it sit for a week or so and then test the voltages to see if there is any significant voltage drop of those low cells. that may indicate problem cells



>This will trickle charge the low packs.

So to do that, can I put my positive and neg leads of my charger here as shown to charge this group?Do I have this diagram right? Or do I charge each cell individually? Pardon mymisunderstanding, im new to this and I dont see any +/- markings on the batteries, they are still allglued together. I wouldn't mind charging the low voltage group (0.25v) of 4 cells, if I knew that was a positive step and where the charger leads should go. Thanks so much for any assistance.

image_wkmqgp.jpg
 
You can actually see the + (positive) marking on the battery
image_xokata.jpg


So Yes find some way to connect one side of the bus bar to the positive and the other to the negative. could be as simple as a clamp (plastic) holding the wires with bared ends to the metal bus bar


Also if you look at your meter on a good set of cells the voltage reads in the positive on the meter then the red test lead is the positive side. If it's a negative number then you have the wire the wrong way around
 
ok, i got this small group on my adjustable power pack, charging real slow @ 100ma.

Here's the number changes after 2 hours on, how is it looking?

image_qeqfpb.jpg


[size=small]2 hours later[/size]

[size=small]image_xddwvw.jpg
[/size]


If I wait till it hits 1.8v, then move to the next group of 6 low voltage cells, then try to charge the whole pack again? Maybe I wont need any new cells at all?Just direct charge these two small groups, bringing them up to more equal voltage of the other cells.

Am I doing this right
huh.png
thanks a lot guys for any input.
 
Yea Looks good. I'd go till 2.5V before moving on to the next cell. if you can turn up the amperage once it hits 1.2V that will be safe
 
Ideally each group of cells should be the same voltage ("in balance").
I have not done this, so it is only from the theory I have learned here...
I would try to get each group of cells to the same voltage before trying to charge with the charger for the whole pack. Do some reading on why balancing is important.
You will also want to check for self discharging on the cells which are lower than the others.
 
Thanks jdeadman, Thanks Oz18650

I got those 2 groups up to 1.8v, i slightly pushed up current after hitting 1.2v to get there. It took about 3 hrs. By the time I removed the charger clips to the other cell group, the voltage has already come back down to .84v , so I think these 2 groups, 12 cells total I will just replace them all. I found 12 cells for us$40 delivered on ebay, so now I will learn how to remove the tabs, remove the cells, and spot weld in the new one's.. wish me luck :)
 
Good luck!
I am sure you will get there in the end.
Are the cells you are purchasing new and exactly the same type? You may want to test that they perform as they should before using them. Apparently lots of cells are deliberately sold performing worse than the ads state.
It is not necessarily all cells in the group that are no good.
You could replace all of them, or you could test them individually to find which are ok. If you go down the test each cell path, you may need to end up joining "llithium anonymous" mentioned elsewhere on this forum- you are already showing the signs.... ?
Just kidding.
But seriously, you will need to work out how far you want to go with rebuilding the pack. If you replace all cells in the bad groups, you will have the extracted ones to test and keep any good ones as spares anyway.
How easy would it be to test/charge each set of cells after you put everything back together?
Is it worthwhile to add a connector to check voltage and possibly individually charge cell groups?
This would allow you to keep an eye on things and manually balance the cell groups if cell groups are not performing the same as each other.
Note: I have no idea if there is any sort of BMS/ balance circuitry in the pack you have.
 
OK, got my replacement batteries and pure nickel solder strips today.

Removed all nickel sheetings and wires from the 12 cells to be replaced. So in order to mimic the groupings of cells and the nickel sheets that are spot welded on top and bottom, with replacement nickel solder strips, is this the correct way to lay out the strips?

image_nzhfpn.jpg


I could not find any type of solid sheets that the original batteries have. It sure would be alot easier to get this sheet material, then snip with scissors to size for each cell group.

Im gonna really have to pay attention here, because the top cell groupings are different from the bottom cell groupings. I have alot of pics of both top and bottom so hopefully I can suss it out :s
 
Hey can you open that PDF file that has how to do charge float? I tried to create an account there but the admin just blocked my email, not sure why. Or maybe you can open and passed the instructions here
Thanks.
 
I’m trying to do the same with my i2 battery pack. Segway refused to charge with two red lights. When I opened the pack this is what it looked like this. Looks like the BMS is fine but the cells split open.

Segway was stored uncharged for a few years. What cells do you guys recommend to replace? Also, is there a way to test the bms?
 
Last edited:
Back
Top