Invacare Xplore lifepo4 Conversion

[Dan]

I'm thinking of doing a full conversion to lifepo4 on the Invacare Storm 4 Xplore.

The first question is are these cells OK?
16PCS 3.2V 100Ah lifepo4 battery CELL 12V 24V36V 48V 105Ah
https://www.aliexpress.com/item/3305421 ... 4c4dKu6Zh2

The battery box is not wide enough because its slimmer at the bottom (the floor of the box is folded and riveted to the inside) but it can be modified.
What metal is the battery box made out of? Can it be welded OK?

[woodygb]

Try a magnet on the battery box ...if it sticks, then it is more than likely steel.

[Burgerman]

I know that the battery area is very close to the MK grp 24 batteries fitted. But the only way to find out for sure is to measure things accurately and look carefully. Nobody else can tell you. It may just fit. If not then yest modify or choose a smaller cell type.

[Dan]

OK, the magnet sticks to it so I'm guessing its galvanised steel.
Across the top of the box its 265MM but the bottom is only 255MM.

So those cells are OK to use in a wheelchair conversion?

I'm to retarded to want to use a smaller cell type.

Would those cells be OK sitting on their side? The battery box is quite long, long enough to fit 6 sitting on their side 210MM with 6 standing up in front of them 131MM = 341MM. There would be enough room to set the remaining 4 on their flat on top of the ones standing on their side.
Image is shit and not to scale, I'm still using Paint Shop Pro 7 from 2000.

[Burgerman]

Would those cells be OK sitting on their side?

Any way up.

[Dan]

OK I'm going to order those cells unless theres something wrong with them.

Plan B would be welding a new bottom onto the box. You can see the bottom 4MM sheet is folded at the ends and pushed up inside the side walls. This makes the bottom of the box 8MM slimmer than the top.
The MK jells are slimmer at the bottom so fit in OK.

[snaker]

You have to accurately measure the battery box first. It must be at least 1cm larger than the cells block. Those 105Ah cells plus insulation + tape seem not fit your battery box.

[shirley_hkg]

After wrapping each PAIR of cells in 0.8mm self-adhesive gasket paper , it measures
310*266*210(H)

[Dan]

I kind of know they will not fit side by side but I live near a light engineering shop. There is quite a bit of extra room outside the box between the motors so I think I can get the box widened. I like the xploer so for me it would be worth it and it will give me something to do this winter.

I was thinking of just using one 1MM or 2MM Polycarbonate sheet between the cells? So is it OK just to use one sheet between each cell?

Maybe I could use this tape also? 500x13x0.02cm its quite thin.
Mxfans 500 x 13cm Self-Adhesive Cardboard 18650 Battery Insulation Gasket Paper
https://www.amazon.co.uk/Mxfans-Self-Ad ... 269&sr=8-3

What about Duct tape and a 1MM Polycarbonate sheet?

[stevelawiw]

Something I did once on my first powerchair to maximise available battery space, take out the battery box and don't use it, so put the batteries in the frame of the chair. May or may not be doable on the Xplore I've not seen it up close.
Alternatively, something I am considering, lower your sights on capacity, save some money and go for something like these instead :- https://www.aliexpress.com/item/4000121191356.html?spm=2114.12010612.8148356.19.7edc2e0d8OsNaQ.
16 would give you 100ah at 24v. It's still a lot more available power than you ever had with lead, and they'll probably fit easy.

[hank]

Stevelawiw sent you a PM message
did you get it

[stevelawiw]

pm'd you Hank

[hank]

[Dan]

Something I did once on my first powerchair to maximise available battery space, take out the battery box and don't use it, so put the batteries in the frame of the chair. May or may not be doable on the Xplore I've not seen it up close.
Alternatively, something I am considering, lower your sights on capacity, save some money and go for something like these instead :- https://www.aliexpress.com/item/4000121191356.html?spm=2114.12010612.8148356.19.7edc2e0d8OsNaQ.
16 would give you 100ah at 24v. It's still a lot more available power than you ever had with lead, and they'll probably fit easy.

The battery box on the xplore is solid and part of the chairs frame. Unfortunately I'm to retarded to do the practical thing and order smaller cells that would be easy to fit. I have order the 205Ah ones. The Xplore can be really hard on batteries so in order to get rid of any range doubt.

What the first thing I should do with a new cell? They have come very charged up.
I'm using this preset to charge one up and discharge it to 2.5V or 3V?

[Dan]

I have order the 205Ah ones.

That should read I have ordered the 105Ah cells, even I'm not crazy enough to buy the 205Ah cells.

[stevelawiw]

Hi Dan, well done! You've probably done the right thing in going for the biggest capacity available
Did you have to pay any additional import fees etc?
I don't think you really have to do anything to the cells other than wire them up, get them in the chair and start enjoying all that range freedom you've invested in!

[Dan]

Hi Dan, well done! You've probably done the right thing in going for the biggest capacity available

Thanks, its not going to be easy and its a lot of work and I will probably need the chairs frame modified a bit but its going to be worth it.

I bought this, 16 105Ah cells that can do 1C continuously and Maximum Pulse Discharging Current：300A
https://www.aliexpress.com/item/33054219276.html

Just under £1200 delivered by UPS in 15 days, all taxes were unfortunately included in the price.

[Dan]

I picked a cell at random just to check one. It was almost fully charged, I charged it up then started to discharge it but had to stop after 10Ah because I did not want to leave it running while I was out oh my house.
Finished up when I got back.
10Ah + 89.5Ah down to 2.9V

[ex-Gooserider]

OK, the magnet sticks to it so I'm guessing its galvanised steel.
Across the top of the box its 265MM but the bottom is only 255MM.

Red flag just went up in my head.... If you are thinking about welding it yourself, be careful to thoroughly remove any sort of galvanizing or other plating from the area you will be working on - ditto any paint, powder coating, etc... Then be sure to use really good ventilation that carries any welding fumes away from you!

Steel is quite weldable, but many of the metal treatments, especially Zinc (galvanizing) or Cadmium (the yellow 'Cad' plate often seen on bolts) are VERY nasty cumulative neurotoxins.... Paint and powder coat fumes can also be seriously unhealthy.... If you have any work being done by a professional shop, they should know about all this, and be set up to handle it, but some DIY folks are not as wary and have a tendency to do themselves in by not taking the right precautions....

ex-Gooserider

[Dan]

Don't panic, my welding days are over. If it needed to be modified I would take it to a proper light engineering shop and let them deal with it.

What about the cable for the interconnections? Would AWG10 silicone be OK? And what size for the balance cables? And for the cable from the pack to the chair?

[Burgerman]

Silicone is more fragile, and for flexi leads like charge cables. PVC 10 sqmm and 125A fuse to power module..

4 or 6 sq mm for silicone charge cables.

[Dan]

Is there any reason not to use 2MM rubber sheet on its own between the cells? Would be OK on its own without the cells being wrapped in anything?

[Burgerman]

As long as the OUTSIDE edges dont touch any metal And the bottom.

[Irving]

As long as there's sufficient isolation then that would be fine. Also remember that the pair of cells that are in parallel don't need insulating from each other as their cases are at the same voltage. So that saves some rubber and some space. 2mm is overkill though for the separators, but good for the surround.

[Dan]

As long as the OUTSIDE edges dont touch any metal And the bottom.

I intend to put a 4MM rubber lining at the bottom of the battery box. There is a brace for the top of the lead batteries 200MM high but that can be removed leaving the box at least 230MM high.

[Dan]

2mm is overkill though for the separators, but good for the surround.

I was thinking of not using any wrap on the cells but make sure they are each surrounded by rubber. Would that be a problem or should I play it safe and use some sort of wrap too?

[Irving]

2mm is overkill though for the separators, but good for the surround.

I was thinking of not using any wrap on the cells but make sure they are each surrounded by rubber. Would that be a problem or should I play it safe and use some sort of wrap too?

As I understand it the cases are connected to one of the terminals and the covering as supplied is very thin and shouldn't be relied on. Hence the separators in the video you posted. So you must isolate them from each other except where they are in parallel.

In your pic previously, you don't need a separator between the LH 2 cells assuming they were wired + to + and - to - but you would between them and the RH cell.

[Dan]

If I was to wrap each individual cell in an extra insulator for extra safety what could I use that's easily available in the UK?

[Irving]

If I was to wrap each individual cell in an extra insulator for extra safety what could I use that's easily available in the UK?

Anything robust enough, but unnecessary to do individual cells... self-adhesive 0.8mm pvc sheet for example

[ex-Gooserider]

Basic thing to remember is that it is arguably less critical WHAT you use, than it is to be 100% certain that what you use is 100% reliable and proof against wear, vibration or any other sort of damage accidental or intentional short of structurally damaging the chair itself (in which case you have other problems....)

Remember that if cells in the pack short to each other there will be much smoke and heat, possibly flames, as this is something that will NOT be protected by any fuses.... So make sure not to let it happen....

ex-Gooserider