Rebuilding Segway i2 battery
 

My recent project

More pictures

Sent you a PM.

Good stuff...

I take dead units and disassemble them.. I have made a machine to test, charge, cycle and capacity check each cell when removed from the pack...bad ones get rejected good ones get recycled..i put in 20 cells at a time,....go play golf....drink beer....come back to graded cells based on capacity...even old cells can still be usable........

Just a thought for next time...

I make the parallel connections dominant in each cell group....it reduces volt drop...probably doesn't matter but I'm a bit ocd....

Nice work...and no smoke....

Oops...ignore me...I've been drinking...

Looks fine....🥛🥛

Very interesting! What cells did you use? Where did you get them? What do they cost? What was your total cost for the rebuild?

I think if I were to 'rebuild' any, I'd be doing what Dorrington says he's doing - Start with a few red light batteries and replace only the bad cells, recycling the good ones from other batteries. My experience with old batteries is that the original cells last a very long time - I've had 2007 batteries which still give 20 miles or more range

I've had really good luck buying used batteries. I have three I2's and I've bought new(er) batteries (all 6 of them) for those machines over the past couple years for an average of about $400 each, some from private sellers, a few from eBay when I find a 'bargain' - I only buy 2014 or newer batteries. I've sold my older batteries (mostly 2006, 2007 and 2008's which were all still in working condition) for an average of about $250 each, so I've upgraded all my batteries to significantly newer ones for about $150 each. I have a spare 7th battery I'm hanging on to just for emergencies, should something happen to any of them

Don

I used same as original li-iron-po4 cells, ebay has everything
Cells cost around 400 to rebuild two batteries, so it is twice cheaper than in your case, although you didn't mess with disassembling, welding etc.
My batteries were completely dead, so I wouldn't be able to sell them
Dorrington, can you share the technology, how did you replace individual cells?
First of all, what I found - it's extremely hard to extract them out of the case and not damage some on the sides (they are glued in, heat gun helps but still brute force involved).
Next, batteries are glued together with epoxy, and very well spot welded on both sides - you definitely won't be able to reuse that metal plates, and more likely will damage cells when removing plates. But maybe Dorrington found better way.

hi..

right....

i take apart the case, use a heatgun on the back of the case until its really hot(don't spend too long in one spot) the cells either fall out when inverted or use a screwdriver to gently lever (picknthebpositive end of the cell, there is a compression ridge)

once apart I desolder the old cells (having first identified the bad groups), remove the nickel plates..(i just use side cutters and peel rather than rip the nickel strip off....carefully!..) where the bad cells are at and then gently drift the cell out of its sleeve!...easy peasy..no need to split the packs...keep the insulating rings from the positive ends of the cells and make sure you only apply pressure on the circumference of the cell....eventually you have a honeycomb of glued sleeves with no cells in...lol

if i'm keeping the cells I clean both ends with a file..do not short circuit or you'll damage the file!

I then push good sleeve-less cells back in where the bad ones were and reweld with nickel strip.

I try to get a feel for the other cells capacity and try to match as far as possible too.

reassemble the pack (carefull soldering)..charge fully and then capacity test.
(I have made a dummy load and can access the bms registers..the discharge process is automated and terminates automatically...the total capacity is recorded)

so far, worst rebuild is 67%, best is 95% of original.

If i have a really bad pack i cannibalise it for good cells..this is where the automatic machine comes in to play..I de-sleeve all the cells and place them in the machine 6 or 23 at a time..and return after a day or two.check the screen to see what each cell has achieved...

my machines are a jumble of wires and 3d printed parts but they do work..

I hope this is clearer?...

Yep, thanks
This is definitely a way to save on cell cost, but from the labour perspective it is the same if not more extensive.
Would be interested to take a look at your machines! Can you post a picture?

lol..

the machine does the work whilst i am at work...so time is no object..and its only fun...

I cant post pictures here...but ill try to find a host.

and yes...very labour intensive but...zero cost!..

have fun

Hey Dorrington,

I tried removing cells from sleeves and this is what I found:
It certainly can be done, the most challenging part is to remove the nickel plates first.
But then...
I have two old banks, cells' sleeves on one are blue, and another - orange (looks like these are more "fresh"). So when I pull out blue ones - there is a insulation washer on positive contact, and it's glued. But on the orange it is only fixed by sleeve, once removed it doesn't stay in place. Which in turn increases risk of short circuit. Have you seen this and if so what was your resolution?

BTW, Dorrington, I just read that there is a thing called "BMS Lock up" - have you heard about it? I have one spare battery that seems to have this issue - cells hold the charge but segway doesn't recognize the battery. Any advice here?

Are you certain that they are Valence Saphion batteries, or spec-to-spec direct equivalent?

I'm certain that they are not valence, but they are same chemical and spec equivalent.

Hello- you seem to be the peopleI have been looking for....those who rebuild their lithium batteries.

I have revived 2 “dead” i167’s by rebuilding their Nickle batteries. I also have gotten a “dead” i180 back on the road by installing a couple of mediocre lithium batteries in place of the long gone originals. However, I want to rebuild the dead ones to get full range.
Schmonoff -Could you send me or post a picture of your cell arrangement? I can suss it out from photos, but you seem to have a really nice layout in one picture.
Also, (and most importantly) could you tell me what cells are you using? I’m assuming 18650 lithium ion @3.2v....but what Ah or mAh? What has me puzzled is why all the groupings are not seeming to be in sets of 8 cells. Thank you in advance.

18650 only defines the physical form factor of the cell. There are several basic chemistry types of lithium ions and even more variants in specifications. You are working with a Segway battery system that is VERY picky about what it will, or will not, recharge.

The Seg batteries contain a LOT of energy. Be SURE you know what you’re doing so that you don’t do damage to yourself or your house.

Understood. The specificity and potential dangers are the reasons that I am researching all this.

The question of the appropriate ampere hours (using 32v LiPO4 cells) remains.

I can open a battery and check directly, but i’m trying to get a jump on this. I also want to cost it out.

Thanks

Each battery contains 46 cells. Top and bottom connections are different. At least in AF revision (I haven't seen others' internals yet).
They are grouped by 8 in general, with exception for center groups - there are 6 and 2 on the another side, and 4 and another 4, and they are connected by thick wires.
Additionally, you can't just replace nickle-cadmium with Lithium, and even if you have complete lithium battery I heard that 1st gen Segways must have firmware updated in order to recognize these batteries.

This is what happens when you apply too much heat when soldering wires... Plastic insulation cap melted and shorted + and -

S-
Yeah, looks like it was time to invite the Campfire Girls! S’mores anyone?
Thanks for the info. BTW, I like the form you setup to arrange the batteries and the polarity identifiers! It probably really helps keep things organized and error free.

What type of tool/system are you guys using to spot weld the jumper nickle bars?

What I first started researching fixing my tool batteries, I read about a company that spot welds the connections. I never did glean what they were using to achieve that.

You can invest in spot welder or do another diy like here
https://youtu.be/b_kGgPVrcCI

Thank you, as soon as I posted my enquiry, I decided to try google search and I found that one and more, including devices on Amazon. Neat stuff.
:thumbsup:

Would you describe how you opened the plastic case of the pack.

I see how you used a Dremel abrasive tool on one side. How did you open the other three sides?

I haven't used dremel, instead I did it as on this video
It takes several minutes, preserves the case and it can be sealed back with silicone.
https://youtu.be/zRLX3ElN-U8

Anyone rebuild battery before? Need opinion
 

Hey all.. I purchased 2 - x2 segway's with dead batteries, both red lights. I was able to use the float charge method I read about here, and got 3 of them charged and working again:D
Thank you rene_canlas

I have one that still goes to red and just wont turn green. It is accepting a float charge and measures 62V prior to re-installing 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. 3 out of 4 is amazing and im very happy with that, but you would think if the other one from this same set worked, why wouldn't this one too?

So, I opened the battery case up and tested each cell and noted the voltage on top of each group. All cells within the group tested the same voltage noted. In other words, I was looking for dead cells, but there were no individual cells that appeared or measured 0, or a different number from any of the others in the same group. ( Im feeling this means something significant )

Like, perhaps the wire that goes to that specific group of cells is bad? Ive never done this before, so just talking out loud. If there's anyone who's been in here before, what would you do next? Re-solder the bad looking connections? Replace all the cells in the most extreme low voltage clusters?

Photo's below and I marked w/arrow some areas of concern. Thanks so much for any input.

Looking at his last picture, they are 3.2 volts, 1500 mah and made in March of 2019

Don

Battery date is 16 january 2007

cell group 1 is bad 0.25v

cell group 12 is bad

cell group 13 or 14 is bad (can't tell which from you pictures)

given the age of the cells, I would replace with new along with the worst other so called good pack, this way at least you will have two good batteries.

when removing batteries, always remove the positive wire first, starting with the big red one and go around in sequence.

DON'T LET ANY WIRE TOUCH ANYTHING ELSE

when you have made, pruchased your replacement cells attache the wires in reverse order, starting with the big black one.

If you're not really sure then let someone skilled do it, it'e easy to kill your bms board...or start a really big fire.

hope this helps.........

You may need this tool:

https://www.ebay.de/itm/Segway-i2-X2...-/323877820781

Is on stock, also cheap versions available.
Cheers M8’s!

Thanks dorrington! truly appreciate your input and tips. I will now attempt to start pulling out those cell groups.

Ive seen quite a few comments that state "Be SURE you know what you’re doing so that you don’t do damage to yourself or your house." but, the fact is, most of us here dont know what were doing, we're trying to learn.

So for you more experienced peeps..
Thats why that simple guide on using the float charge method, written by rene_canlas is so incredibly helpful. Just spell it out, step by step, just about anyone can follow along.

So now im off to tryout your last very insightful post.. gently drift the cells out of its sleeve.. ok off i go.

oh, one thing, no one said anything about this leaky solder joint.. is this normal?

https://forums.segwaychat.org/attach...5&d=1569903644

I would think that should be fixed before anything else. Thanks so much guys for your input and help.

Thanks for the input felix_fetche, but If i know I have 12 bad cells, it will cost me about US$50 to replace the cells. I dont need to spend a penny, or EUR 333,00 (US$365) on what I already know [:(!]

Leaky joint
 

Nothing wrong with the joint as far as I can see.....

Segway x2 replacement cells?
 

Need 12 cells to replace a couple bad groups inside of a pack.
Is this the correct replacement cell?

LiFePO4 Battery 18650 3.2V 1500mAh UL&UN38.3

is 3.2V 1500mAh correct?

Ive heard the Segway bms may not recognize all 18650 LiFePO4 cells?
If this is not it, what would the exact search term be to find them?

Thanks so much

Joe

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? Attached Images

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 new cells, Just direct charge these two small groups, bringing them up to more equal voltage of the other cells.

Am I doing this right? thanks a lot guys for any input.

Some cells will come back to life, I get around 30-40% usable cells from my old packs.

it only takes one cell of the group of four to develop an internal short and the whole set is unservicable.

I use an imax b6 charger to balance charge the pack without segways intervention,...then do a capacity test on each bank of four....if there is a big difference say 2-300 mA then i scrap the pack and harvest the good cells..I arrange them by individual cell capacity, after a few batteries i have a spare cells that are close enough to match existing cells

Only change just the bad ones if you're on a really tight budget, don't be cheap...buy new, my last lot were $1.50 each!

from my experience the bms does not care who made the cells as long as they are well balanced from a capacity point of view..that's the important bit.

Even new cells can have capacity differences...I match my cells as far as possible,...I capacity test each cell (ebay from china, not accurate I only care about numbers not actual capcity), wite the value on each cell, then charge them (miboxer c8..brilliant bit of gear) arrange them so that the total capacity of each group of four is as close as possible..then assemble.


phwew my fingers hurt now!...

dorrington, wow thanks man, you are so helpful, i really appreciate all your great experience.. and hard typing :) :thumbsup:

So, i think i should replace these 12 cells, they do charge up after a 2-3 hour charge, from .25v to 1.8v, but the voltage drops very fast after disconnecting charger.

I saw you mentioned "lifepo4 cells from alarmhookup on fleabay".
Im sorry Im not clear on exactly which rating to get,
is it 3.2V 1500mAh ?

Would this be the one's to get?

they are LiFePO4 18650 3.2V 1500mAh
https://www.ebay.com/itm/352610893740

Cheers man! :)

If they hold 3 volts or so for a couple of weeks then they might be usable...however it's still important to know the capacity, they may hold voltage but only have 500mA...

sounds like at least one cell in the banks that drop is bad....you'll have to disconnect all four to find the bad one, replace it and re-weld or solder back together...

I got a cheap welder from ebay $100 and some nickel strip, far better then soldering and alot faster..

I would advise new cells, repair your machine and enjoy it....disconnect the old packs and weed out good cells at your leisure...if you get another old pack do the same...eventually you'll have enough rescued cells for a new pack.....

like I posted before,.to get the cells out, carefully peel the connecting strips off..when both sides of the cell are removed, push the cell out of it's sleeve using a wooden dowel on the negative end, a light tap will help,...keep the insulating washer!..replace with a good cell (with its sleeve removed)....

Hope this helps...it's not a quick process
....


those look fine to me, 23x4 = 92 cells per battery...$350 per battery...not too bad and 6.0AH..

>If they hold 3 volts or so for a couple of weeks then they might be usable

thats a great point, REALLY good to know.
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 charge 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 will get those 12 cells for us$45 delivered on ebay, so now I will start to remove the tabs, remove the cells, and since it's only 12 cells, I rather not buy a spot welder for this, I think i'll try to just solder the new one's in .. wish me luck :)

and thanks again for your kind support and help here.