Lithium Build for Magic Mobility X4

[swalker]

Has the seller got back to you about the bad battery?

Yes! We have exchanged 3 rounds of emails:

• I sent a description of the problems and they responded with an assurance they will resolve the problem and asked me to send pictures
• I set 24 pictures documenting the issues and they responded with a request for detailed pictures by cell
• I set 76 pictures documenting the issues with each cell with tags showing the unique cells and they responded with a confirmation of receipt and a statement that they are looking into it.

They have been very responsive. I will keep you updated as I learn more.

Steve

[Burgerman]

Maybe they shipped returned cells by mistake. Every warehouse has rather cheap employees if you know what I mean. That dont give a monkeys about anything.

[ex-Gooserider]

I would be raising serious issues with the vendor about the damaged cells - dents and squashing on electronics parts is a BIG red flag.... There is a You-Tube video of a person taking a Headway cell apart, basically the inside is a stack of very thin layers of alternating electrode materials and insulators, with NO extra space inside... Any dent in the case means the inside bits have also been squashed, with unknown, but probably BAD results... Even if they test OK initially, I'd expect shortened lifespans and lowered reliability....

As a side note, the rules about shipping 'damaged' or 'returned as defective' cells are far tougher than for 'new' cells - I suspect you'd have a hard time even finding a shipper that would accept them if properly labeled (at least some of the package photos I've seen suggest that the Chinese shippers are not always following the rules...)

Definitely raise a case w/ your credit card company and / or Paypal... I tend to play 'hardball ' and open a case right off the bat, and tell the vendor that I am doing so simply to preserve my interests, and not run the risks of having time limits run out, but that I will be happy to close the case as 'resolved satisfactorily' as soon as we have reached a reasonable agreement...

ex-Gooserider

I just had a look at all 16 cells. About half are fine but six of the cells are noticeable dented on the same corner. Increasing from slightly dented to quite a lot dented/squashed, I think this is also causing the bulging on one of the side the cell. It's lucky I'm not tight for space in the battery compartment. I've found some 2.5mm rubber gasket sheet that I will cut to size and use as insulation between and around the cells. That will stop the creases/bulges rubbing through the plastic film on the cells.

I think one the boxes of eight cells must have tumbled from a height, or been dropped while being carried, causing the outer box to split open along one edge. The inner cell boxes are fine but the shock/force/energy was obviously transmitted into the cells resulting in the damaged casings.

It's just one them things, hopefully they will all test okay. Afterall the electricity comes out the top half

[Scooterman]

I would be raising serious issues with the vendor about the damaged cells - dents and squashing on electronics parts is a BIG red flag.... There is a You-Tube video of a person taking a Headway cell apart, basically the inside is a stack of very thin layers of alternating electrode materials and insulators, with NO extra space inside... Any dent in the case means the inside bits have also been squashed, with unknown, but probably BAD results... Even if they test OK initially, I'd expect shortened lifespans and lowered reliability....

I just had a look at all 16 cells. About half are fine but six of the cells are noticeable dented on the same corner. Increasing from slightly dented to quite a lot dented/squashed, I think this is also causing the bulging on one of the side the cell. It's lucky I'm not tight for space in the battery compartment. I've found some 2.5mm rubber gasket sheet that I will cut to size and use as insulation between and around the cells. That will stop the creases/bulges rubbing through the plastic film on the cells.
I think one the boxes of eight cells must have tumbled from a height, or been dropped while being carried, causing the outer box to split open along one edge. The inner cell boxes are fine but the shock/force/energy was obviously transmitted into the cells resulting in the damaged casings.

HI, Gooserider thank you for your reply. And I do appreciate what you say, dented cells obviously aren't ideal.
But I didn't deal directly with a dealer so it's a bit tricky, Shirley got them for me. But I don't blame him it's not his fault. I think from looking at the tracking/shipping info they came direct from his battery guy.
They were delivered by UPS but I don't know at what stage in the shipping, the box got dropped. I don't think UPS shipped the two boxes of cells all the way from the far east, I think they shipped them from their German hub. Perhaps If I noticed sooner I could have complained to UPS, but it's difficult without any official paperwork.
If I get trouble with the dented cells in the future I'll just have to buy some equivalent replacements. I'm sure Shirley would be able to source the same cells or something similar. But I'm hoping I won't have to and they'll be okay.

[ex-Gooserider]

True, I hadn't realized that you had gotten them through Shirley.... I think Shirley is a great guy and I have no hesitation in getting stuff through him, but at the same time it does make life more difficult if there is a problem...

ex-Gooserider

[Scooterman]

I think Shirley is a great guy and I have no hesitation in getting stuff through him, but at the same time it does make life more difficult if there is a problem...

ex-Gooserider

I totally agree, I'm the same as you. I've enjoyed dealing with Shirley, it's been good fun. And I would definitely ask for his help in the future (sourcing stuff). I would much rather deal with him than go through a marketplace, I'm nervous of them places, (but others seem to get on okay with them). Shirley's good to do what he does for people, it must be a lot of work for him.

[terry2]

Has the seller got back to you about the bad battery?

Yes! We have exchanged 3 rounds of emails:

• I sent a description of the problems and they responded with an assurance they will resolve the problem and asked me to send pictures
• I set 24 pictures documenting the issues and they responded with a request for detailed pictures by cell
• I set 76 pictures documenting the issues with each cell with tags showing the unique cells and they responded with a confirmation of receipt and a statement that they are looking into it.

They have been very responsive. I will keep you updated as I learn more.

Steve

Good to hear.

Lets us know the out come.

[swalker]

I wanted to report back on the resolution of the issue with my LiFePO4 cells. As I noted in previous posts, I have been in contact with the seller and they have been very responsive.

After working with them on the issues, I offered to have them do one of the following:

1. Send me a new set of cells (with them paying the shipping). I have not found a carrier that will ship damaged cells to China, so I offered to dispose of the damaged set.
2. Refund half the purchase price (not including shipping) and I would take the risk that the damaged set of cells would work well enough for my purpose.

They chose option 2, which I am OK with. They have sent the money via paypal and I am back to working with the cells to get them ready to install in the Magic Mobility X4 wheelchair.

While I would have preferred to get an unbulged set of cells with no signs if prior use, I am satisfied with the outcome. I give the seller high marks for handling this situation to my satisfaction.

Steve

[expresso]

I think that's a good deal - its good to know that they at least worked it out - - it would have been a pain to ship them back if you even can - like you said - no one wants to -

Now let me ask you this - did you pay with paypal ? did you call them and just worked it out with them - without having to open an dispute with paypal etc, ?

in my case - I had issues with two orders - I felt and both same seller - wanted to give him another try - turned out I had to force them to refund some - and also to send replacement Cell for one weak one - if it wasn't for paypal that stopped payment - opened dispute - they wouldn't have done it

so if they did it without an open dispute - you didn't force them - that's good customer service - which to me is important - glad its over with and I bet you can enjoy them for many years

looking forward to how they are - in use - charging results etc,

[swalker]

I was prepared to open a paypal dispute, but never needed to.

The seller took this action without any pressure from me. I just supplied the facts to the vendor.

Steve

[ex-Gooserider]

Glad to hear things worked out...

PayPal has been pretty good the times I've invoked them, and since having to many cases can cause them grief, vendors are generally pretty anxious to resolve issues in order to make the problem go away...

The problem is that Pay-Pal and eBay both have pretty tight time limits on how long after a purchase one can open a case. If the time limits expire they won't do anything, and the vendors know this as well... Especially with overseas vendors where it can take a while for shipping, by the time you get a problem item there might not be a lot of time to open a case...

I've heard of cases where vendors will sort of act like they are being friendly and trying to resolve the problem, but responding slowly in order to 'run out the clock' on your ability to make a case, then disappear...

By opening a case right off the bat, you keep this from happening - you don't have to worry about the time limit, instead the vendor now has time limits on his response to reach a resolution....

It seems like a good way to 'keep them honest'

ex-Gooserider

[expresso]

thats great they worked with you without having to dispute it -

i also agree with scootherman - some try to waste time and that bothers me - i didnt waste time with my situation because i wasnt getting an email back from them when i first told them about it - so i went right to paypal to at least protect myself - paypal gives you 90 days - thats not too bad - enough time to start a dispute

which i did both times - the first time the seller took his time and didnt seem to care - till after a month he realized paypal took the money back - then he started to work with me - and at the end begging me to stop the dispute - which i though was funny - all i asked for was a replacement Cell for the weak one and i showed them the graphes from the Pl 8 to prove it -

seller didnt care - till paypal stopped payment and holding it - paypal actually told me - send it all back and they would refund me - but i didnt want to do that - and finally i got replacement cell - 2nd time around same seller - i figure i give him a chance - and he had the Cells i wanted - size wise - 80ah etc, which i am using now

my dispute was they lowered the price right after i purchased them - and also the fact that i dont give the full 80ah out of them - they response was that i would get full 80ah if charged fully to 3.65v and discharged fully down to 2.0v - only then you get the rated Ah out of them - either way - they refunded me the difference from the sale price -

they didnt want to deal with paypal dispute again - so paypal is good to use in these cases - and i wont order from them again - matter of fact - i placed another order from another seller on alibaba - 100ah Cells - curious to check them - seems very nice seller and seems honest - i expect at the very least 85ah at 2.9v

they state 96ah at 2.0v min. so that means 85ah to 90ah min for me at 2.9V if that is what it gives me - i be Ok with it - Only Cell that is high quality and you get what they say - are the headways - - as long as understand the specs of the Cell and what to expect - you wont be disappointed

from my experience - and maybe otherrs have better sellers they deal with etc, - any cell you find - take10ah off the top and expect no more than that - thats fine - dont expect a full 100ah from a 100ah cell - unless you run it down to there specs - which most say 2.0v or 2.5v - if you follow that rule - you wont be shocked - you know what to expect and happy -

now if you get 75ah out of a 100ah cell - then i wont be happy and consider that something is wrong there - 85ah - 90ah - its fine - anything more even better

[swalker]

Now that the issue of the cells' condition has been resolved, it is time to get to work on building the battery pack.

I have charged each cell using the appropriate presets BM provided. I discharged each cell by 20 Ah for storage while the issue with the vendor was resolved. Once the resolution was in place, I charged each cell again and we started building up the battery pack.

We wrapped each cell in fish paper (electrically insulating paper) which was secured with electrical tape. We then encased each cell in PVC shrinkwrap.

After doing that, we built the wires needed to connect the cells together and assembled the cells in the the pack. There will be four cells on the right side and four cells on the left side of my wheelchair.

There is 5mm thick EVA foam between adjacent cells. This is non-conductive foam that is pretty compressible. It works great in accommodating the shape of the bulged cells.

I fully charged the battery pack (again, using the appropriate presets BM provided). I am now in the process of discharging the battery.

Here are some pictures to show what we have done so far.

[swalker]

More Pictures

[expresso]

that looks very nice - clean - they should ship them to us already wrapped this well to begin with

do you have a link to that fish paper ? does it have glue on it already - what size wiring did you use for those connections 6 awg ?

what size shrink wrap is that - ? came out perfect shrink wrapped

[swalker]

I bought the fish paper from digikey: https://www.digikey.com/product-detail/ ... -ND/257752

It was not self adhesive. I could not find a good source of self adhesive, so went with the regular stuff. I would have preferred self adhesive.

For the yellow connecting wire I used 6 AWG (13.3 mm2) tinned copper wire. I could not find any with silicone insulation, so used some with standard insulation.

I used Selterm tinned copper ring terminals for those connectors. Oddly enough, the 6 AWG Selterm ring terminal barrels were too large. Following their recommendation, I went down (up in number) a size to 8 AWG and those fit very well. I measured the diameter of the 6 AWG wire and it was the diameter it is supposed to be. Since the cells take 6mm bolts, I used 1/4 inch ring terminals. Life would be easier if we could just work in metric!

The shrink wrap is https://www.amazon.com/gp/product/B07FX ... UTF8&psc=1. It is 250mm wide (when flat) and 0.15mm thick. It is much thicker than the insulating material that was on the cells. We left the original insulation in place. That shrink wrap shrinks about 50% across the tube and around 15% along the length of the tube. It was easy to use with a heat gun. We used https://www.amazon.com/gp/product/B07FX ... UTF8&psc=1 for the heat gun.

I could not find a true AWG crimp tool for the connectors. I settled on https://www.amazon.com/gp/product/B00MV ... UTF8&psc=1, which did a great job of cutting and crimping the 6 AWG wire and 8 AWG terminals. We crimped first with the 16 (mm2) setting and then with the 10 (mm2) setting.

Steve

[expresso]

thanks for the break down - try this place next time - they have alot of ring heavy duty connectors also - i just got some 6 awg ring and 8 also

https://www.waytekwire.com/products?clear=true

i dont understand what you did - you used 6 awg wire on a 8 awg ring terminal and it fitted good ? i find it hard to fit 8 awg with 8 awg rings

i can do it - but hard to fit some solder in there - also i found 6 awg wire silicone also - i think at progressive.com - for hobby stuff

you did a great job and you have alot of room in your chair - on mines - i would have to always keep it as thin as i can to make it fit -

[swalker]

Thanks for the info on a source for wire and terminals.

For the Selterm terminals I used, you are supposed to step down a size when using twisted wire, especially fine twisted wire. I did not know that until I ordered the 6 AWG terminals. Those were huge. I re-read the info and found that they suggested 8 AWG terminals, which fit very well.

I found 6 AWG copper wire with silicone insulation. But, I really wanted tinned copper and could not find that with silicone insulation. Note that the ProgressiveRC 6 AWG silicone wire is only "tinned at both ends". I wanted it tinned along the entire run. Hopefully, I can find some for the next build.

Getting access to the battery box in my X4 requires quite a bit of disassembly. Thus, I have not yet test fit the new cells. I am sure hoping they fit!

Each set of 4 cells (including all the insulation) comes out at about 174 to 175mm wide. The lead acid batteries currently in the chair (MK M24 SLD G FT) are 173mm wide. It "looks" like there is an extra millimeter or two, so I am quite hopeful this will all fit just fine.

As for the other dimensions, the 4 cells (including insulation, wiring, etc.) are 258mm long (Mk M24 SLD G FT are 259mm long) and 210mm high (MK M24 SLD G FT are 209mm high).

Each battery box is 175mm wide (I think), 286mm long, and can accommodate a battery 230mm high. Width is the only dimension that is a concern.

I am sure looking forward to getting the new battery pack in the chair and seeing how it does. We have snow predicted for all next week, so it may be after that until I get to take it for a spin.

Steve

[expresso]

https://www.amazon.com/SELTERM-Battery- ... th=1&psc=1

this is what you used ? i just got some 6 awg terminals and yes they are huge - didnt know they made tinned wire all the way the whole cable

yes the progressive have tinned ends only - - sounds like you got it figured out - i be waiting to hear once you start using them and charging graphs etc,

funny i just found another 180ah Cell - with good size specs - maybe they may be the same cells - wonder how they come up with the Cap. when making them - and how do they know the C rate of the Cells -

you could find an hydraulic crimper easily - you used a manual one - how hard was it - did they make a good crimp you think ?

[terry2]

More Pictures

Glad you got it sorted.
Maybe get someone else to blag just one off them for testing? That would replace your damaged one.

You've wired it up different to me. Maybe I will try your way if I can get my cells balancing together.
It's confusing me(not hard) the way you have wired the balance cables

[Gnomatic]

Looking good, swalker. That is some giant pvc heatshrink there! What size is that?

[swalker]

Terry2: I have two sets of 22 AWG wires, with 9 wires in each set.

The first set is for the balance cables. Those are connected to the positive terminal on all the "in between" cells (and the positive and negative of the entire battery pack at the end cells).

The second set is for the cell monitor. Those are connected to the negative terminal on all the "in between" cells (and the positive and negative of the entire battery pack at the end cells).

Gnomatic: The blue PVC shrink wrap is 250mm when unshrunk and flattened out. I got it here: https://www.amazon.com/gp/product/B07FX ... UTF8&psc=1. It is available in a variety of sizes, including larger sizes. It has a roughly 2:1 shrink ratio. It shrinks about 15% lengthwise, which took a bit of experimenting to figure out. The first cell we did got covered 3 times, the first two attempts being pretty laughable. Good thing that it came in a 10 ft roll.

Steve

[Gnomatic]

How did you figure out/calculate that the flat 250mm heat shrink was the right size for your cells?

[Burgerman]

Presumably he measure right around, or added 2x width and 2x length.

E.G the cell is say 130 x 50 x height. So you just say 260 plus 100 x2? So you want one thats is bigger than 720mm circumference, or 360 wide. By as little as they have.

[swalker]

The PVC heat shrink tubing I bought is 250mm when flattened out (unshrunk). If formed into a cylinder, it would obviously have a circumference of 500mm.

The cells are 54mm thick x 173mm wide. So, I needed something that, when flattened out, was wider than 54+174 = 228mm. I figured that 250mm was large enough to easily go over the cells once the were wrapped in fish paper (the stuff I used is 0.010 inches thick). I thought 300mm would be too wide.

The shrink ratio across the tube is about 2:1 (48% to 50% shrink, per the specs). So, I could have used 300mm, for example, but I would have to do more shrinking. In my opinion, less shrinking is better.

Steve

[Gnomatic]

Well that's pretty straight forward and makes sense. Thanks.

[Gnomatic]

I bought the fish paper from digikey: https://www.digikey.com/product-detail/ ... -ND/257752

It was not self adhesive. I could not find a good source of self adhesive, so went with the regular stuff. I would have preferred self adhesive.

A little late but here is some self-adhesive insulating gasket tape.

[expresso]

@ Swalker - i noticed you have the Revo PSU - how long have you had it and any issues with ? i considered one but i heard so many others having issues - for one reason or another - not sure if was user error or the PSU - i heard from the Revo PSU and another one which has an adjustable voltage - forget the name

so i never bothered and always got used 24V units off ebay - have to say they never gave me an issue - have 4 of them - but i would like an unit like yours next time maybe - what is your take on it ? good - worth it ?

thanks

[expresso]

I bought the fish paper from digikey: https://www.digikey.com/product-detail/ ... -ND/257752

It was not self adhesive. I could not find a good source of self adhesive, so went with the regular stuff. I would have preferred self adhesive.

A little late but here is some self-adhesive insulating gasket tape.

not for me i may try this myself - this would be all i need to wrap the cell - how thick is that one - 1mm ?

good one

[Gnomatic]

I bought the fish paper from digikey: https://www.digikey.com/product-detail/ ... -ND/257752

It was not self adhesive. I could not find a good source of self adhesive, so went with the regular stuff. I would have preferred self adhesive.

A little late but here is some self-adhesive insulating gasket tape.

not for me i may try this myself - this would be all i need to wrap the cell - how thick is that one - 1mm ?

good one

Its listed as 0.2mm thick.