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Make Lifepo4 cell box

PostPosted: 07 May 2019, 22:55
by martin007
Hello.

I'm considering adopting Lifepo4 batteries.
The main obstacle is how to fit these batteries into my chair.

wc_01.pg.JPG


Ideally, a metal box.

How have done you?

Re: Make Lifepo4 cell box

PostPosted: 07 May 2019, 23:59
by Burgerman
Where do the LEAD batteries usually fit?

Re: Make Lifepo4 cell box

PostPosted: 08 May 2019, 00:11
by martin007
Boxes...


img_20160224_130428.jpg

Re: Make Lifepo4 cell box

PostPosted: 08 May 2019, 10:48
by Burgerman
Then you need to find the biggest Ah that will fit in each box. Can be 4S or 8S. In each box.

What size are the lead bricks?

Re: Make Lifepo4 cell box

PostPosted: 08 May 2019, 13:39
by Scooterman
I have boxes on my small scooter but would do away with them if convert it to lithium. Simpler

Re: Make Lifepo4 cell box

PostPosted: 08 May 2019, 15:11
by martin007
What size are the lead bricks?


30 ah - 33 ah

I have boxes on my small scooter but would do away with them if convert it to lithium. Simpler


What alternative do you suggest?

Re: Make Lifepo4 cell box

PostPosted: 08 May 2019, 15:35
by Scooterman
Put all 8 cells in a single box. Buy or make the box.

Re: Make Lifepo4 cell box

PostPosted: 08 May 2019, 16:48
by martin007
Buy or make the box.


It's not that easy...

I'll also need to host powertec somewhere.

Re: Make Lifepo4 cell box

PostPosted: 08 May 2019, 18:33
by Scooterman
Down the road, I think you may run into connection problems with two boxes. Especially if you sometimes remove boxes to transport chair by car.

Just my opinion....

Re: Make Lifepo4 cell box

PostPosted: 09 May 2019, 01:17
by Burgerman
If both are 24V boxes, and both connect via andersons, then it will run on one or two boxes, and no connection issues with those. The charge cables will be sub D connectors, one on each box.

Re: Make Lifepo4 cell box

PostPosted: 10 May 2019, 19:20
by martin007
Does anyone know if those boxes are used outside the field of powerchairs?
Do those boxes have a technical name?

Re: Make Lifepo4 cell box

PostPosted: 10 May 2019, 19:26
by Burgerman
Boxes... :cussing :thumbup:

Re: Make Lifepo4 cell box

PostPosted: 10 May 2019, 19:48
by LROBBINS
Yes, they are used elsewhere and in English they're called "battery boxes". Here's what McMaster-Carr stocks:
battery boxes.jpg

Re: Make Lifepo4 cell box

PostPosted: 10 May 2019, 19:58
by martin007
And what's this technically called?

duda.jpg

Re: Make Lifepo4 cell box

PostPosted: 11 May 2019, 01:14
by Burgerman
I doubt anyone knows. You could create that from bolt/spacer/washer. Theres hundreds of different types of bolts and fixings.

Re: Make Lifepo4 cell box

PostPosted: 11 May 2019, 19:30
by martin007
Burgerman wrote:I doubt anyone knows. You could create that from bolt/spacer/washer. Theres hundreds of different types of bolts and fixings.



OK.

Thanks.

Re: Make Lifepo4 cell box

PostPosted: 14 May 2019, 00:48
by ex-Gooserider
As others have said, you are either going to have to make those boxes work, or build something custom... Those are almost certainly proprietary, so you will be mostly on your own for building...

A plastic box is nice in that you don't need to worry as much about insulating the outside of the packs, but a sheet metal box would be easier to make... A reasonably decent sheet metal shop should be able to turn out a custom box without a lot of trouble....

Ah rating is not a highly useful number for telling what size a battery is... Better is to have the 'Group Size' if not the dimensions... This is the first thing I found w/ Duck-Duck - https://www.batterystuff.com/kb/tools/bci-battery-group-sizes.html

Sounds like you might have size 'U-1' batteries - which is not unusual for a portable type chair - they are small and underpowered, but light as lead bricks go... Unfortunately I don't know if we have any 'recipes' for battery sizes that will work for them. It may also be a challenge to come up with a pack that can supply the required current in such a small size.

It may be worth looking at the chair design to see if it would be possible to fit a larger box or set of boxes...

ex-Gooserider

Re: Make Lifepo4 cell box

PostPosted: 14 May 2019, 21:46
by martin007
It may be worth looking at the chair design to see if it would be possible to fit a larger box or set of boxes...


The space available is very small and fair. banghead banghead

Re: Make Lifepo4 cell box

PostPosted: 15 May 2019, 01:41
by farmer
build a add-on like expresso and others have,
hang on back and be done with it

Re: Make Lifepo4 cell box

PostPosted: 15 May 2019, 01:41
by farmer
build a add-on like expresso and others have,
hang on back and be done with it

Re: Make Lifepo4 cell box

PostPosted: 07 May 2020, 04:46
by shirley_hkg
You can convert / modify the 2 boxes into ONE easily , with 3 thin sheets of PVC boards glued by silicon sealant.

You then have a better compartment , or even more height to accommodate more Ah. cheers


Re: Make Lifepo4 cell box

PostPosted: 07 May 2020, 11:20
by Irving
Would be good to have pics of boxes in chair to get feel of layout. Personally I'd ditch boxes, make new 4S packs out of largest cells in space available and fabricate simple U-shaped hangers to match the fixing points - maybe just webbing straps would suffice since LiFe packs are much lighter...